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Neuromotor task trainingNiemeijer, Anuschka Simone

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1-Niemeijer - titelpagina

Neuromotor Task Training: physiotherapy for children

with developmental coordination disorder

Anuschka S. Niemeijer

NEUROMOTOR TASK TRAINING FOR CHILDREN WITH DCD

i

PARANIMFEN Ingrid Falkena Mark A. Niemeijer This study was sponsored by an unconditional grant from the Health Care Insurance Board [College voor Zorgverzekeringen], the Netherlands. Niemeijer, Anuschka S. Neuromotor Task Training: physiotherapy for children with developmental coordination disorder Dissertation University of Groningen, the Netherlands – with summary in Dutch ISBN 978-90-77113-61-5 Lay-out design: Peter G.M. Mol Cover design: Frank Holtkamp Child on cover: Lars G. Vosselman Printed by: GrafiMedia, University of Groningen © Copyright 2007, A.S. Niemeijer All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronically, mechanically, by photocopying, recording or otherwise, without the prior written permission of the author.

2- Niemeijer - RUG aankondiging

RIJKSUNIVERSITEIT GRONINGEN

Neuromotor Task Training:

physiotherapy for children with developmental coordination disorder

Proefschrift

ter verkrijging van het doctoraat in de Gedrags- en Maatschappijwetenschappen

aan de Rijksuniversiteit Groningen op gezag van de

Rector Magnificus, dr. F. Zwarts, in het openbaar te verdedigen op

donderdag 5 juli 2007 om 13:15 uur

door

Anuschka Simone Niemeijer

geboren op 21 augustus 1970

te Delft

2- Niemeijer - RUG aankondiging

Promotores Prof. dr. T.W. Mulder

Prof. dr. B.C.M. Smits-Engelsman

Copromotor Dr. M.M. Schoemaker

Beoordelingscommissie Prof. dr. M. Hadders-Algra Prof. dr. M.J. Jongmans Prof. dr. K. Postema

ISBN 978-90-77113-61-5

TABLE OF CONTENTS

3- Niemeijer - TOC

Contents Chapter Page 1 Introduction

1

2 Children with developmental coordination disorder: comparison of a referred and non‐referred group Submitted

11

3 Neuromotor Task Training for children with developmental coordination disorder: a controlled trial Developmental Medicine & Child Neurology 2007; 49: 406‐411

23

4 Verbal actions of physiotherapists to enhance motor learning in children with DCD Human Movement Science 2003; 22: 567‐581

39

5 Are teaching principles associated with improved motor performance in children with developmental coordination disorder? A pilot study Physical Therapy 2006; 86: 1221‐1230

57

6 Fine motor deficiencies in children diagnosed as DCD based on poor grapho‐motor ability Human Movement Science 2001; 20: 161‐182

75

7 General discussion

97

Summary

105

Samenvatting (summary in Dutch)

113

Dankwoord

119

Curriculum Vitae

125

Northern Center for Healthcare Research (NCH)

129


3- Niemeijer - TOC

4- Niemeijer - Chapter1 introduction

Chapter I Introduction


2 4- Niemeijer - Chapter1 introduction

espite normal intelligence, about 5 to 10% of school-aged children have difficulty adequately performing movement tasks that are part of their daily routine. Because of their motor difficulties, they might not get asked to play by

peers, or they might withdraw from leisure activities because they feel they lack sufficient skills to enjoy participating. General practitioners, when consulted by parents about a child’s poor motor performance, may refer the children to a paediatric physiotherapist (PPT). PPTs can draw on an array of treatment approaches. Evidence for the effectiveness of these approaches for children who perform movement tasks poorly, however, is scarce. The aim of this thesis is to evaluate a new physiotherapeutic treatment programme called ‘Neuromotor Task Training’ (NTT). NTT was developed especially for children with poor motor performance in daily activities.

Developmental Coordination Disorder Over the years many labels have been used to describe children with motor difficulties, e.g. abnormal clumsy children (Orton, 1937), physically awkward children (Wall et al., 1990), children with coordination problems and difficulties (Sugden & Henderson, 1994), children with specific developmental disorder of motor dysfunction (World Health Organisation, 1992). The term which is fast becoming internationally accepted is developmental coordination disorder (DCD). DCD was first introduced in 1987 in the ‘Diagnostic and Statistical Manual for Mental Disorders’ (APA; DSM-III; 1987). The label DCD can be applied when four criteria are met (Table 1): Table 1. Diagnostic Criteria for Developmental Coordination Disorder (APA: Diagnostic and Statistical Manual of Mental Disorders-IV-TR; 2000; page 58). Criterion Description A Performance in daily activities that require motor coordination is

substantially below that expected given the person’s chronological age and measured intelligence. This may be manifested by marked delays in achieving motor milestones (eg, walking, crawling, sitting), dropping things, “clumsiness”, poor performance in sports, or poor handwriting.

B The disturbance in criterion A significantly interferes with academic achievement or activities of daily living.

C The disturbance is not due to a general medical condition (e.g., cerebral palsy or muscular dystrophy) and does not meet the criteria for a Pervasive Developmental Disorder.

D If Mental Retardation is present, the motor difficulties are in excess of those usually associated with it.

D

INTRODUCTION


Nature and aetiology of the disorder The DSM-IV criteria are not so specific that all children who meet the criteria make up a homogeneous group. Children with DCD differ in the motor skills they experience difficulties with. Frequently reported skills that are hard to master are writing and drawing, dressing (incl. buttoning, tying shoe laces), locomotion (walking, climbing or descending stairs, hopping, running, jumping), handling tools (such as scissors, cutlery, hammer, garden tools), speech (irregularities, stammer), constructional play, ball skills, and outdoor play and sports (skipping rope, swinging, roller skating, swimming, climbing, etc.) (Geuze, 2007). There may be several reasons why a child succeeds or fails. Research into the underlying processes has shown a wide range of deficits associated with DCD (e.g.: proprioceptive, kinaesthetic, visual perception of object size and object orientation, motor planning, motor programming, execution of movements, timing, force control, internal modelling, ability to disengage attention, interhemispheric transfer). In a meta-analysis, Wilson and McKenzie (1998) found that visual spatial processing is the main deficit associated with DCD. However, also in dysfunction of underlying processes a lot of variance exists between children with DCD. Some subgroups of children with DCD have been described, but what subgroups are found depends heavily on how children were selected, and the test items and statistical methods used by researchers (Macnab et al., 2001). In addition, children with DCD not only differ in the motor skills they experience problems with, or the underlying processes that are causing the deficit, but also in the extent to which they suffer from (different) co-morbidities or co-occurring problems such as attention deficit and hyperactivity disorder (ADHD). It is thus important to realize that the aetiology of the motor coordination difficulties might differ for each individual child. Because the group of children with DCD referred to receive treatment will be very heterogeneous, therapy can not follow a fixed recipe.

Long‐term consequences In contrast with what lay people, school teachers and healthcare professionals often believe, at least 50-75% of children with DCD do not outgrow their problems (Cantell, Smyth & Ahonen, 1994; Christiansen, 2000; Geuze & Borger, 1993; Hellgren, Jilbergt, Gillberg, & Enerskog, 1993; Losse, et al., 1991). Actual figures are assumed to be higher, but can not be proven due to lack of motor tests suitable for use with adolescents. Lack of practice, due to not participating in physical activities, may inhibit further motor development, possibly aggravating existing performance differences between a child with DCD and its peers. The poor performance of a child often invites ridicule by their peers. In the long term, suffering from DCD can lead to difficulties in other behavioural domains such as self concept, social skills, and academic success. Children with DCD might for example not fulfil their cognitive potential (Losse et al., 1991). In children with both motor (DCD) and attention problems (ADHD) a higher incidence of



depression has been found; 13% versus 7% in typically developing children (Gillberg & Gillberg, 1989). In addition, as children with DCD often withdraw or are being shut out from sport settings or playgrounds, their fitness becomes less (Peters et al., 2004), which raises their chance of clustered cardiovascular risk (Andersen et al., 2006). A vulnerability for other possible diseases as osteoporosis, obesity, type 2 diabetes mellitus, mental health problems has been described as well (Petersen et al., 2004). Given the impact poor motor performance can have in childhood and later, when children grow up, it is important for children with mild motor problems to be identified and treated.

Effectiveness of Treatment programmes The available treatment methods for children with DCD can roughly be divided into process-oriented and task-oriented approaches. Process-oriented are those treatment methods that aim at the underlying process or processes which the child has not developed adequately for his/her age and which are thought necessary for the successful performance and acquisition of motor skills. In these approaches, a task is broken down into subcomponents that are trained separately. By addressing the underlying processes, transfer to many tasks in which the trained processes are necessary is expected which would be an advantage. It is, however, very difficult to derive the true underlying processes, and to design activities that address these processes. Examples of these methods are the widely used sensory integration therapy (Ayres, 1972) and kinaesthetic training (Laszlo et al., 1988). Mandich et al. (2001) reviewed the literature and concluded that although process-oriented (bottom-up) approaches have a long tradition, these approaches have not shown to be reliably better than no treatment at all. In a meta-analysis of 13 intervention studies, Pless and Carlsson (2000) also found little support for process-oriented treatment effectiveness. More recently, task-oriented approaches have been developed in which specific skills are taught. Examples are: a task-specific intervention programme developed by Revie and Larkin (1993), the ‘cognitive orientation to daily occupational performance (CO-OP)’ programme developed in Canada (Martini et al., 1995, Polatajko et al., 2001), and ‘Neuromotor Task Training’ (NTT) in the Netherlands. For task-oriented (or top-down) approaches the evidence is accumulating (Pless & Carlsson, 2000; Mandich et al., 2001).

Neuromotor Task Training NTT was developed because the effectiveness of available intervention programmes was disappointing. In traditional treatment sessions, Dutch physiotherapists often apply what they have learned on various courses in an eclectic fashion. In stead of practising functional skills, traditional treatment programmes focus on prerequisites which are believed mandatory for adequate task performance. These programmes provided to

INTRODUCTION


children with DCD do not comply with current insights. In literature, research concerning motor learning has concentrated on three distinct subjects: a) how to instruct people, b) how to practice skills, and c) how to provide feedback. In addition, one notices three consistent findings which are important in relation to training motor skills in children with a coordination disorder: the low level of transfer from one acquired motor skill to the next, the large contextuality of the acquired motor functions, and the 'time on task principle'. The newly developed NTT treatment programme incorporates recent scientific knowledge on the variables affecting motor control and motor learning in order to enhance motor learning in general, in particular as regards the transfer of skills to activities of daily living. In this introduction, the important variables will be mentioned. For a more detailed description of NTT, we refer to Schoemaker and Smits-Engelsman (2005). NTT is a tailor-made, child-centred, and mainly task-oriented treatment programme. It focuses strictly on teaching those skills that a child needs in daily life. A physiotherapist treating according to NTT teaches those motor tasks with which a child experiences problems. A child will not be practising a wide range of assumed conditions that do not form part of that specific skill. Not the selective improvement of mobility or muscle strength is regarded as proper therapeutic goal for improving motor functions; it is creating interactions between the child and its environment that will result in acquiring new or improved motor functions. The ultimate goal of NTT is the ability of a child to transfer the skill acquired in the treatment situation to his or her daily life situation. The higher the resemblance between the treatment situation and the circumstances in which the skills are needed in daily life, the more successful the transfer of skills practised to daily life will be. Therapists start by assessing the strengths and weaknesses of a child's functional motor performance. They select the tasks that will be trained. These tasks will be different for each child, depending on its individual needs as well as the expectations, capabilities, and motivation of both the child and its parents/carers. The therapist will determine the entrance level of training of a skill by loading various aspects of the task performance. For example, in goal-directed movements, speed or accuracy in relation to distance and target size can be examined. During the assessment, therapists analyze which processes are involved in deficient motor skill performance. For instance, a child may fail to learn a specific motor skill due to lack of motivation, fear of failure, attention problems, or lack of understanding how to execute a particular skill. However, successful performance might also be hampered by motor control processes such as action planning (making wrong choices under changing stimulus/response conditions), movement planning (inability to perform the skill as complexity increases or sequences become longer), motor programming (poor timing of movement patterns and sequences), parameter setting (executing an activity but not with the required speed



and force; non optimal use of biomechanical characteristics), or initiating force (fine-tuning of the force recruitment is coarse). During NTT, functional training exercises are designed in such a way that the therapists can continue to analyse which motor control processes are deficient within the task to be trained. For example, if ball catching improves in a secure and supportive surrounding, task training will aim at more psychological processes. If however a child can catch the ball only when standing still or warned beforehand, gradually ball catching in more complex or more attention demanding situations will by trained. If the child hasn’t developed a throwing pattern yet, the opportunity of merely throwing a variety of objects (that vary in size, weight, material) will be given. Later, a demand on parameter setting will be introduced by propelling the object over various distances or by aiming the objects at targets of different sizes. Through this approach, functional skills are trained in such a way that they tap the processes that are thought to be involved in the child’s motor problems. Special attention is paid to how therapists teach the children. Explicit motor learning in general and transfer in particular can be enhanced by applying effective motor teaching principles. What principles are used depends on the child’s learning stage. When children try to acquire new motor skills, they go through distinct stages. Fitts and Posner (1967) described a three-stage model which is still one of the most influential models for motor acquisition (Magill, 2001). For each skill to be learned, therapists trained in NTT guide children with DCD through these three stages. In the first stage, the beginning level, children are engaged in cognitive activities to detect what movement co-ordination pattern will be required to achieve the goal of the skill. They need to solve problems such as ‘what is the goal of this task’; ‘which limbs do I need to achieve this goal?’; and ‘in what position do I need to hold my limbs?’. In this phase, therapists might demonstrate the task, provide time for (guided) self-discovery, compare the task with familiar tasks, or provide immediate, precise and positive knowledge of performance. In this phase, constant practice is required, as the goal of treatment in this phase is to acquire a basic co-ordination pattern. During the second stage, the intermediate level of motor learning, variability of practise within the same skill is introduced. Children learn to master the basic co-ordination pattern of the skill and refine their performance. They still make errors in this stage, but their errors are fewer and less variable. Changes in task demands (speed, accuracy, weight, material) provide the child the opportunity to vary task performance. In this way, task performance may be refined and adapted to the specific demands of several task situations. It is hypothesised that variability of practice will enhance transfer of learning during treatment to daily life motor skill performance (Magill, 2001). In this stage, therapists can provide ample opportunity to practice, a supportive non-threatening environment, short practice sessions with frequent breaks, and constructive feedback. Only after much practice, children will reach the third stage of skill learning, the

INTRODUCTION


advanced level. In this stage, children are able to perform a skill almost automatically, thus without much conscious attention. Therapists can promote enthusiasm, provide encouragement and motivation, provide feedback on specific aspects, use many different relevant contexts of increased difficulty (as close as possible to real life situations), increase complexity by combining tasks (sequentially and temporally), and suggest alternative strategies. A common idea of the relationship between contextuality and transfer to novel contexts is that the more variants of a specific task are met in training, the greater the likelihood that any future variant will be one previously met (Magill, 2001). Although NTT is a task-oriented approach, the theoretical framework behind it differs from other recently developed task-oriented approaches, such as CO-OP (Polatajko et al., 2001). In CO-OP, DCD is considered to be a motor learning disorder and cognitive strategies are taught to enhance motor learning. This is in contrast with NTT, which is based upon a cognitive neuroscience approach to motor control. Although cognition plays a role in NTT treatment, for instance when therapists ask various questions about task performance and problem solving, cognitive strategies are not explicitly taught but motor tasks are trained in various, gradually more challenging, circumstances. During NTT, the therapists tap the motor control processes that are assumed to be deficient while training functional skills. NTT focuses on learning a task within a variety of contexts. In the example of ball throwing, the distance, the angle, the target size or even the weight of the ball may be varied. In this way, the parameterization process is trained. NTT might, therefore, appear as a mere process-oriented approach, but (goal-directed) ball throwing is practised within a task specific training paradigm. This new Dutch treatment approach has become part of the curriculum for paediatric physiotherapists at Avans+, university for professionals.

Aims and outline of this thesis The main objective of this thesis was to evaluate ‘Neuromotor Task Training (NTT)’, a new physiotherapeutic programme developed especially for children with developmental coordination disorder. Because NTT is task-oriented and pays special attention to the question of how children are taught motor skills, we also wanted to gain an understanding of the assumed intervening mechanisms of NTT. To evaluate NTT, we conducted two studies: (1) a controlled trial in which two groups of children with DCD participated (chapter 2-5), and (2) a trial in which children participated who were diagnosed as having DCD based on poor grapho-motor ability (chapter 6). For the controlled trial, two groups of children with DCD were recruited. In both groups, all children experienced motor problems in school and/or at home. These groups were not randomly selected but existing groups, which made them vulnerable for initial differences. Because these differences might be relevant for the extent to



which the groups develop spontaneously or due to treatment, in chapter 2, we compare the motor and behavioural characteristics of the groups. In chapter 3, we present the controlled trial. In this chapter, we investigated whether 9 ‘weekly’ 30-minute sessions of NTT were effective for children suffering from DCD. In addition, because NTT is a task-oriented approach and effects of therapy are often small in terms of total scores on general movement tests, we investigated whether children improved particularly on tasks comparable to those trained. Furthermore, we explored whether behavioural characteristics of the children, such as attention problems, interacted with the extent to which their treatment was successful. In the courses on NTT, therapists were taught about motor learning theories, and the best ways to improve motor learning. In chapter 4, we describe the development of a taxonomy of the verbal actions of physiotherapists that aimed at enhancing motor learning. With the motor teaching principles taxonomy (MTPT), we investigate whether therapists were treating the children according to the NTT guidelines with regard to motor learning. As the physiotherapists’ verbal actions were intended to improve motor learning, we examined the associations between the teaching principles used and the success of treatment after 9 and 18 treatment sessions (chapter 5). In chapter 6, we present a study evaluating the effectiveness of NTT in children with poor grapho-motor ability. In the first study (chapter 2 to 5), we used mainly general motor tests to select children or to evaluate NTT. But one of the most common reasons for remediation is problems with handwriting. Handwriting is a very complex fine motor skill, and children with poor grapho-motor ability might thus form a specific subgroup of children with DCD. The DSM-IV explicitly mentions handwriting as an example of the daily motor activities which pose difficulties for children with DCD (Table 1, APA, criterion A). Therefore, in chapter 6, we describe a study in which we selected children with DCD on the basis of poor grapho-motor ability. To evaluate NTT, we used one of the manual dexterity test items (the flower trail drawing item) of an often used general motor test (the Movement Assessment Battery for Children, M-ABC; Henderson & Sugden, 1992). Besides changes in the outcome on the flower-trail item, we wanted to gain insight into changes in the underlying drawing process brought about by NTT. For this reason, the children performed the flower-trail item on an XY-digitizer. Finally, in chapter 7, we present and discuss the main findings of the studies conducted and described in this thesis. General conclusions are presented and recommendations for further research are suggested.

References American Psychiatric Association. (2000). Diagnostic and statistical manual of mental

disorders (4th ed, text revision,). Washington, DC: APA.

INTRODUCTION


American Psychiatric Association. (1987). Diagnostic and statistical manual of mental disorders (3rd ed,). Washington, DC: APA.

Andersen LB, Harro M, Sardina LB, Froberg K, Ekelund U, Brage S, Anderssen SA. (2006). Physical activity and clustered cardiovascular risk in children: a cross-sectional study (The European Youth Heart Study). The Lancet, 368:299-304.

Ayres AJ. (1972). Sensory integration and learning disorders. Los Angeles: Western Psychological Services.

Cantell MH, Smyth MM, Ahonen TP. (1994). Clumsiness in adolescence: educational motor and social outcomes of motor delay detected at 5 years. Adapted Physical Activity Quarterly, 11:115-129.

Christiansen SA. (2000). Persisting motor control problems in 11- to 12-year-old boys previously diagnosed with deficits in attention, motor control and perception (DAMP). Developmental Medicine and Child Neurology, 4:4-7.

Fitts PM, Possner MI. (1967). Human Performance. Belmont, C: Brooks/Cole. Geuze RH. (2007). Characteristics of DCD: on problems and prognosis. In: Geuze RH.

(ed). Developmental coordination disorder: a review of current approaches. France, Marseille: SOLAL. p 9-25.

Geuze RH, Borger H. (1993). Children who are clumsy: five years later. Adapted Physical Activity Quarterly, 10:10-21.

Gillberg IC, Gillbeg C. (1989). Children with preschool minor neurodevelopmental disorders. IV: behavioral and school achievement at age 13. Developmental Medicine and Child Neurology, 31:3-13.

Hellgren L, Jilbergt C, Gillberg IC, Enerskog I. (1993). Children with deficits in attention, motor control and perception (DAMP) almost grown up: general health at 16 years. Developmental Medicine and Child Neurology, 35:881-892.

Henderson SE, Sugden D. (1992). Movement Assessment Battery for Children; manual. Sidcup, Kent: the Psychological Corporation.

Laszlo JI, Bairstow PJ. (1985). Perceptual Motor Behaviour – Developmental assessment and therapy. London: Holt, Rinehart and Winston.

Losse A, Henderson SE, Elliman D, Hall D, Knight E, Jongmans, M. (1991). Clumsiness in children – do they grow out of it? A 10-year follow-up study. Developmental Medicine and Child Neurology, 33:55-68.

Macnab JJ, Miller LT, Polatajko HJ. (2001). The search for subtypes of DCD: Is cluster analysis the answer? Human Movement Science, 20:49-72.

Magill RA. (2001). Motor learning: concepts and applications. Madison, WI: McGraw-Hill.

Mandich AD, Polatajko HJ, Macnab JJ, Miller LT. (2001). Treatment of children with Developmental Coordination Disorder: what is the evidence? Physical & Occupational Therapy in Pediatrics, 20:51-68.



Martini R, Polatajko HJ. (1998). Verbal self-guidance as a treatment approach for children with developmental coordination disorder; a systematic replication study. The Occupational Therapy Journal of Research, 18:157-181.

Orton ST. (1937). Reading, writing and speech problems in children. New York: Norton.

Peters JM, Henderson SE, Dookun D. (2004). Provision for children with developmental co-ordination disorder (DCD): audit of the service provider. Child: Care, Health and Development, 30:463-479.

Pless M, Carlsson M. (2000). Effects of motor skill intervention on DCD: a meta-analysis. Adapted Physical Activity Quarterly, 17:381-401.

Polatajko HJ, Mandich AD, Missiuna C, Miller LT, Macnab JJ, Malloy-Miller T, Kinsella EA. (2001). Cognitive orientation to daily occupational performance (CO-OP), part III: the protocol in brief. Physical & Occupational Therapy in Pediatrics, 20:107–123.

Revie G, Larkin D. (1993). Task specific intervention with children reduces movement problems. Adapted Physical Activity Quarterly, 10:29-41.

Schoemaker MM, Smits-Engelsman BCM. (2005). Neuromotor task training: a new approach to treat children with DCD. In Sugden D, Chambers M. Children with developmental coordination disorder. London: Whurr.

Sugden DA, Henderson SE. (1994). Help with movement. Special Children 75:Back to Basics 13.

Wall AE, Reid G, Paton J. (1990). The syndrome of physical awkwardness. In: Reid G (ed.) Problems in movement control. Amsterdam: Elsevier Science. p. 283-315.

Wilson PH, McKenzie BE. (1998). Information processing deficits associated with developmental coordination disorder: A meta-analysis of research findings. Journal of Child Psychology and Psychiatry and Allied Disciplines, 39:829-840.

World Health Organization. (1992). International Statistical Classification of Diseases and Related Health Problems (10th ed.) Vol. 1 ICD-10. Geneva: WHO.

5- Niemeijer - Chapter 2

Chapter 2 Children with developmental

coordination disorder: comparison of a referred and non‐referred group

Anuschka S. Niemeijer Marina M. Schoemaker

Bouwien C.M. Smits-Engelsman

Submitted for publication


Chapter 2

12

Abstract Motor and behavioural aspects that might influence the perceived need to access special services for children aged 5-10 years suspected of having a developmental coordination disorder (DCD) were examined. One group of 36 children (29 males, 7 females; mean age 7y3mo, SD1y0mo) recently referred for paediatric physiotherapy (referred group) and a group of 18 children (13 males, 5 females; mean age 7y4mo, SD1y11mo) whose parents had not, as yet, sought professional help (non-referred group) were tested with the Movement Assessment Battery for Children (M-ABC), Test of Gross Motor Development-2 (TGMD-2), and Child Behaviour Checklist (CBCL). The groups did not differ in age, and performed equally poor on the M-ABC. The non-referred group had more difficulty with M-ABC’s manual dexterity and less with M-ABC’s ball skills. Their quality of gross motor patterns (TGMD-2) was below average but significantly better than that of the referred group. No differences were found in the relatively high CBCL scores. In subgroups of children performing at or below the 15th centile on the M-ABC, the same pattern of results was found. Not the severity but the nature and appearance of the difficulties seem to influence the parental decision to get a referral for treatment.

CHILDREN WITH DCD RECEIVING TREATMENT


13

iven the impact poor motor performance can have on children,1 and the fact that special services can be effective,2,3 it is important for children with mild motor problems to be identified and treated. These children may withdraw

from sport settings or playgrounds realising that they lack sufficient skill to enjoy participation. By doing so, their fitness declines, they might not get asked to play with peers, and they are likely to develop a sedentary life style.4 Nowadays, the diagnostic label Developmental Coordination Disorder (DCD) can be used for approximately 5-10% of school-aged children.5 Table 1 provides the DSM-IV-TR criteria for DCD. 6,

Table 1. Diagnostic Criteria for Developmental Coordination Disorder (APA: Diagnostic and Statistical Manual of Mental Disorders-IV-TR; 2000; page 58). 6

Criterion Description

A Performance in daily activities that require motor coordination is substantially below that expected given the person’s chronological age and measured intelligence. This may be manifested by marked delays in achieving motor milestones (eg, walking, crawling, sitting), dropping things, “clumsiness”, poor performance in sports, or poor handwriting.




Not all children with DCD access help from recognised health or educational professionals.4 The aim of this study was to obtain insight into the question why some children suspected of having DCD get treated and others do not. To study the use of treatment, we used a model proposed by Andersen and Newman7 which distinguishes three different categories of variables.8 One category consists of predisposing variables, such as demographic factors, variables related to social structure, and variables related to health beliefs. For children suspected of having DCD the predisposing variables seem unimportant, since Niemeijer et al.9 found no differences in social background (including educational level of the parents), living environment, or age at which motor milestones were reached. Another category is formed by enabling factors. This category is related to the availability of healthcare facilities in the community and economic characteristics of the family.7 In the Netherlands, most specialised care is only available after referral by a general practitioner (GP), who acts as a “gate keeper” for specialized care. Since 2006, children with DCD have been able to get physiotherapy without a GP’s referral, but at the time of our research, a GP’s referral was needed for physiotherapy. For both the visits to the GP, and special services such as physiotherapy,

G


Chapter 2

14

the reimbursement of costs depends on parents’ level of health insurance. In the Netherlands, nearly everyone has health insurance and there is a good spread of services throughout the country with equal quality of care and equal pricing. Therefore, these enabling factors which can have a major influence on use of services in other countries are not important when studying the differences between Dutch children who do and do not use health care services.10

Variables in the predisposing and enabling categories do not seem to explain why some children with DCD get treated and others not. Therefore, we study the influence of variables in the third category: the health needs like symptoms, diagnoses or disabilities.7 Two groups of children who experience problems in daily life due to poor motor performance are tested with two reliable motor tests: the Movement-ABC11 and the Test of Gross Motor Development-212. In addition, the Child Behaviour Checklist13 is administered in order to examine whether behavioural symptoms, such as attention problems, may be factors that influence the need to seek professional help.

Method

Selection of participants For this comparison study, we included two groups of children suspected of having DCD. Since there is no ‘gold-standard’ test to check whether criterion A to diagnose DCD (Table 1) applies for a child, we selected children with motor problems that had an impact on tasks of daily living or school performance (criterion B). The children were either recently referred to physiotherapy (referred group) or their parents were concerned about their motor development but had not, as yet, sought professional help for them (non-referred group). All children attended Dutch mainstream schools and had an IQ above 80. Thus far, Dutch children with serious learning difficulties (i.e. IQ < 80) attend special schools. The inclusion criteria were a) aged between ages 5 and 10; b) experiencing motor problems that have an impact on tasks of daily living or school performance; c) no medical condition thought to have caused the motor problems; and d) no prior physiotherapy. The referred group consisted of children whose parents went to their GP and discussed the motor coordination problems in school and/or at home. Because of these problems, the child was referred to physiotherapy. The child was checked by the GP and PPT for obvious neurological disorders and other medical conditions that could explain the motor difficulties. This group was selected during 2 years by 40 physiotherapists. According to the physiotherapists these children were fulfilling the criteria for DCD. The non-referred concern group was included within 1 year after we had spread an A3-poster in mainstream schools. On the poster a child was depicted whose legs were



15

strapped, and symptoms of DCD were written around the child, e.g. ‘clumsiness’, ‘poor handwriting’, ‘bumping into things’, or ‘two left hands’. The text “Are you having concerns about your child’s motor development? Have your child tested!” was printed boldfaced. The poster offered parents free motor testing. A priori, we believed that one SD difference (about 5 points) on the M-ABC would indicate a clinical meaningful difference between groups. Based on a 90% power to detect a significant difference with α = 0.05, the required sample size was 21 children per group. Sixteen children per group were required for 80% power. The Medical Ethics Committee of University Medical Center Groningen approved this study. Parental informed consent was obtained for all participating children.

Instruments The Movement Assessment Battery for Children (M-ABC) provides an indication of a child's motor functioning in daily life as it gives an estimate of motor competence in terms of speed, accuracy and distance.11 Four age-related batteries measure different aspects of motor ability; three items measure manual dexterity, two items measure ball skills and three items measure static and dynamic equilibrium. The obtained scores depend on the age of the child, which makes comparison of the performance among a broad age-range possible. A lower total impairment score (TIS) represents a better movement execution outcome. The test has a moderate to good validity and reliability.11;14;15 It is also validated for the Dutch population.15 The reliability (rs) of the cut-off scores in the Netherlands ranged from .43 to .97 for the different age-bands.16 In addition, Leemrijse et al. found the Standard Error of Measurement to be 3.13 points, where the mean TIS ranged from 13.2 to 15.4 and SDs ranged from 3.9 to 7.5.17 In accordance with Geuze et al.’s proposal, 5 we use the 15th centile cut-off score to distinguish children with DCD from children who perform within age norms (criterion A for DCD). The Test of Gross Motor Development-Second Edition (TGMD-2)12 was administered because it assesses how children co-ordinate their trunk and limbs during a fundamental movement task performance rather than the time spend or the errors made.12 It measures 12 skills that are usually acquired by children in pre-school and early elementary grades. It contains two subtests: (a) a locomotor subtest (LM) formed by running, galloping, hopping, leaping, horizontal jumping, and sliding, and (b) an object control subtest (OC) with six propel and receive skills: striking, bouncing, catching, kicking, throwing, and rolling. The TGMD-2 provides three to five performance criteria for each skill. Every skill is demonstrated by the test administrator, after which the child is asked to perform the action. The child is given two test trials. Each time a performance criterion is met, one point is given. All points are added over skills per LM or OC subtest. A higher score indicates a better quality of movement patterns. The TGMD-2 manual provides tables to calculate standard scores per subtest for ages 3-10. The use of these standardised scores allows for a description and


Chapter 2

16

comparison of the performance among a broad age-range. These scores have a mean of 10 (SD = 3), and together they can be converted into a composite Gross Motor Quotient (GMQ) which has a mean of 100 (SD = 15). The GMQ is the best estimate of an individual's gross motor development.12 Analysis of unpublished Dutch raw reference scores (n=138 in total, ages 4-10) showed a correlation with age (LM boys r = .72 & girls r = .69; OC boys r = .81 & girls r = .66), as was also shown by Ulrich16. By definition, the standardised scores were not supposed to correlate with age. We found no high correlations, except for girls of eight years and older (LM: boys r = .17& girls r =.02; OC: boys r = -.11 & girls r = -.46: for girls till the age of eight r = .10). Based on these results, it was assumed that the TGMD-2 could be applied for Dutch boys, and Dutch girls till the age of eight. The TGMD-2 has a high degree of reliability and low test error. The interrater reliability and the stability-over-time reliability coefficients varied between r = .88 and r = .98 for both the LM and OC subtests and the GMQ. The reported Standard Error of Measurement is 1 for the standard scores and 4 to 5 for the GMQ.12 The Child Behaviour Checklist, CBCL13, is a parent questionnaire to assess problems in 4–18-year-olds. The second part of the CBCL (120 items) was used in which information is gathered on behavioural or emotional problems during the past 6 months. T-scores can be obtained for eight problem syndromes, and for internalizing and externalizing behaviour. The T-scores make comparisons possible between the scales, and between ages since they are corrected for age and gender. T- scores above 60 (82nd percentile) or 63 (90th percentile) indicate behaviour in the clinical range.18 The good reliability and validity of the CBCL13 was confirmed for the Dutch translation.18 An experienced test administrator tested the children individually in a quiet room. He was blind for the referral status of the child.

Data analyses In this study, we described and compared the age, motor performance and behavioural symptoms in a referred and non-referred group. First, we described and compared the differences between the (initial) groups of children suspected of having DCD. For these group comparisons we used t-tests. Second, we compared the variables in subgroups consisting of children who performed at or below the 15th centile on the M-ABC. In this study, these children were considered to have DCD. In accordance with Geuze et al’s proposal, we used the 15th centile cut-off score on the M-ABC to distinguish children with DCD from children who perform within age norms (criterion A for DCD). Since the subgroups of children with DCD were smaller, they were compared with Mann-Whitney U-tests. The significance level alpha was set at 0.05. In order to find out whether the groups differed in the number of children scoring in the clinical or at-risk range we calculated odds ratios with 95 % confidence intervals.



17

Results Fifty-four children suspected of having DCD were tested (n=54). Of these children, 36 were recently referred to 17 of the 40 participating paediatric physiotherapists (28 males and 8 females; mean age 7y3mo; SD 1y0mo) and 18 had parents who were concerned about their child’s motor development (13 males, 5 females; mean age 7y4mo, SD=1y11mo). The groups did not differ in age [t(22.5) = -0.04, p = 0.97]. In the group of 36 referred children, 29 (81%) were considered as having DCD because they scored at or below the 15th centile (22 males and 7 females, mean age 7y1mo; SD=1y1mo). In the non-referred group, we found 13 out of 18 children (72%) to have DCD (10 males and 3 females with mean age 7y2mo, SD=2y1mo). Also in these smaller subgroups, the mean age was not statistically different [MW Z=–.40; p = 0.69].

Motor performance Both groups of children suspected of having DCD did not differ on the M-ABC total score [t(52) = 0.63, p = 0.53]. They scored on average 14-15 points (table 2); a score that is obtained by less than 5% of the school-age population. Moreover, they performed poorly on all different aspects of motor ability measured with the M-ABC. However, the non-referred group had more difficulty with manual dexterity and less with ball skills (on the M-ABC). In addition, the non-referred groups’ quality of gross motor patterns was described as below average (GMQ between 80 and 90), and is significantly better than the referred group whose qualitative performance was described as poor (between 70-79) [t(52) = –3.34, p=.002]. In the non-referred group, the GMQ ranged between 58 and 103 whereas the range was between 55 and 94 in the referred group. The same pattern of results was obtained when the two subgroups of children performing at or below the 15th centile on the M-ABC were compared (table 2). In addition, between the groups suspected of having DCD, we found no differences in the amount of children who performed below the 15th centile (OR=0.63; 95%CI: 0.17-2.35) or the 5th centile (OR=0.80; 95%CI: 0.25-2.50) on the M-ABC (table 3). Whilst, more referred children performed at or below the 15th centile on the TGDM-2 (OR=3.50; 95%CI: 1.04-11.8), or the 5th centile (OR=5.0; 95%CI: 1.23-20.3). In the non-referred group, one child performed within age norms (one SD) on both tests (5%), whereas 4 of the 36 referred children (11%) performed within age norms on the tests [OR = 0.47; 95%CI: 0.05-4.55; n.s.].

Table 3. Classification of children scoring below the 15th/5th centile on the TGMD-2 or M-ABC

Non-referred group (n=18) Referred group (n=36)

<15 centile <5th centile <15 centile <5th centile

TGMD-2 9 (50%) 3 (17%) 28 (78%) 18 (50%) M-ABC 13 (72%) 10 (56%) 29 (80%) 22 (61%) M-ABC: Movement Assessment Battery for Children:11 a lower score is better; TGMD-2: Test of Gross Motor Development-2:12 a higher score is better


Chapter 2

18

Behavioural aspects The average group CBCL-scores were within the clinical range on the social and attention problems scales (table 4). Between the groups, none of the differences in problem-scale scores reached statistical significance. However, we found a tendency for the non-referred group to internalize their problems more often. Whereas the number of children scoring in the clinical range was about the same for each symptom scale (no significant odds ratios), there was a difference between the smaller subgroups for internalizing behaviour. In the subgroups of children with DCD, 4 referred children (14%) and 6 non-referred children (46%) internalized their problems to such a degree that they scored within the clinical range (OR = 0.19; 95%CI: 0.04-0.89).

Discussion According to the M-ABC total impairment scores, the health-like needs for treatment are equal in both groups studied: a group of children whose parents had concerns about their development and a group of children that was recently referred for physiotherapy. Although no significant differences were found in severity of motor difficulties, as assessed motor by the M-ABC, the nature of the children’s difficulties differed. The pattern of results was the same for the initial groups suspected of having DCD, and the (smaller) subgroups existing of children who performed at or below the 15th centile on the M-ABC. In terms of speed and accuracy, the non-referred groups had more difficulty with manual dexterity items, and better ball skills compared to the referred. groups. Furthermore, their quality of movement patterns was significantly better, though it was below average. The CBCL scores revealed that in both groups many children suffered from social and attention problems. Although no differences between the compared groups were found on the CBCL symptom scales, we found a tendency for the non-referred group(s) to internalize their problems more. From the initially selected groups, a comparable amount of children (ca. 25%) was excluded from the secondary analyses. Taking the 15th centile on the M-ABC as a cut-off score to check whether criterion A for DCD applies for a child, suggests that children performing within the age norms on the M-ABC are not suffering from DCD. Geuze et al.5, however, also found that 25% of referred children who were judged to have DCD (by a team of rehabilitation specialists - rehabilitation doctor, occupational therapist, and physical therapist) performed above the 15th centile on the M-ABC. In addition, experimental studies show that the correlation between different motor abilities is generally low and none of the existing tests of motor functioning covers the whole range of motor abilities.19 There is no “gold standard” test for DCD with high sensitivity and specificity. Therefore, as recommended by Geuze et al.,5 the lenient 15th

centile cut-off is used for DSM-IV’s criterion A for DCD. Nevertheless, there is evidence that the M-ABC’s items are not exhaustive enough to identify children in need for

5- N

iem

eije

r - C

hapt

er 2

19

Tabl

e 2.

Per

form

ance

of s

elec

ted

grou

ps o

n th

e M

-ABC

11 a

nd T

GM

D-2

12; m

eans

and

SD

s

Child

ren

susp

ecte

d w

ith D

CD

Child

ren

with

DCD

N

on-r

efer

red:

n=1

8 R

efer

red:

n =

36

t-va

lue

p-va

lue

Non

-ref

erre

d: n

=13

R

efer

red:

n =

29

Z-va

lue

p-va

lue

TGM

D-2

GM

Q

86.3

(11.

5)

76.4

(13)

-2

.74

.008

90

.0 (1

5.3)

74

.6 (1

1.2)

-2

.66

.008

TG

MD

-2 L

M

7.8

(2.8

) 6.

2 (2

.8)

-1.9

8 .0

53

8.6

(3.4

) 5.

8 (2

.1)

-2.1

7 .0

3

TGM

D-2

OC

7.6

(2.1

) 5.

9 (2

.4)

-2.5

9 .0

12

8.1

(2.5

) 5.

7 (2

.2)

-2.1

9 .0

29

M-A

BC T

IS

14.1

(6.4

) 15

.2 (6

.0)

0.6

3 .5

3 16

.7 (5

.4)

16.8

(5.6

) 0

.34

.97

M-A

BC m

anua

l 7.

2 (3

.7)

4.8

(3.2

) -2

.52

.015

8.

8 (3

.1)

5.3

(3.3

) -2

.96

.003

M

-ABC

bal

l 2.

3 (2

.5)

4.5

(2.8

) 2

.78

.008

2.

3 (2

.5)

4.9

(2.8

) 2

.71

.007

M

-ABC

bal

ance

4.

5 (3

.5)

5.9

(3.4

) 1

.38

.17

5.6

(3.4

) 6.

5 (3

.3)

0.4

1 .9

7

Tabl

e 4.

Sco

res o

n th

e sy

mpt

om sc

ales

of t

he C

hild

Beh

avio

ur C

heck

list (

CBCL

) 13 ;

mea

ns a

nd S

Ds

Ch

ildre

n su

spec

ted

with

DCD

Ch

ildre

n w

ith D

CD

N

on-r

efer

red:

n=1

8 R

efer

red:

n=3

6 t-

valu

e p-

valu

e N

on-r

efer

red:

n=1

3 R

efer

red:

n=2

9 Z-

valu

e p-

valu

e

With

draw

n 59

.4 (7

.0)

57.2

(7.3

) -1

.1

.30

59.8

(7.2

) 57

.4 (7

.3)

-0.9

2 .3

6 Ph

ysic

al c

ompl

aint

s 58

.4 (9

.3)

54.7

(6.6

) -1

.44

.16

59.1

(10.

0)

55.0

(7.1

) -1

.08

.28

Anx

ious

/Dep

ress

ed

59.4

(9.6

) 55

.9 (7

.5)

-1.3

9 .1

7 59

.5 (1

0.4)

56

.0 (7

.5)

-0.8

3 .4

0 So

cial

60

.4 (6

.5)

62.0

(9.0

) 0

.70

.51

61.2

(6.7

) 63

.4 (9

.5)

0.6

3 .5

3 Th

ough

t 58

.2 (9

.9)

55.5

(8.5

) -1

.0

.33

58.9

(9.7

) 56

.4 (8

.6)

-0.8

5 .4

0 A

tten

tion

63.1

(11.

0)

62.6

(8.5

) -0

.17

.87

65.8

(11.

0)

62.7

(8.5

) -0

.90

.37

Del

inqu

ency

54

.4 (7

.7)

55.7

(7.9

) 0

.57

.57

54.5

(7.8

) 56

.6 (7

.8)

-1,2

0 .2

3 A

ggre

ssiv

e 58

.1 (1

0.4)

57

.3 (8

.7)

-0.2

7 .7

9 58

.2 (1

0.8)

56

.9 (9

.0)

-0.1

1 .9

1

Inte

rnal

izin

g 59

.7 (1

0.1)

53

.1 (1

1.3)

-2

.01

.05

59.8

(11.

2)

53.9

(10.

9)

-1.6

6 .1

0 Ex

tern

aliz

ing

53.5

(14.

0)

53.1

(13.

1)

-0.0

9 .9

3 54

.1 (1

4.0)

53

.2 (1

2.7)

-0

.24

.81


20 5- Niemeijer - Chapter 2

special services. For example, handwriting that is frequently one of the targets for remediation4 is not measured by the M-ABC.20 Moreover, in accordance to other studies,19;21 we found that children performing within age norms on one test can perform <1SD on another motor test. Therefore, we are not sure that the children performing within age norms on the M-ABC are not suffering from DCD. In both groups, children had social and attention problems. These associated problems have been described earlier.22 Noteworthy is that the non-referred group tends to internalize their problems more often which might mask the impact of their motor difficulties in daily life. Further research with larger sample sizes might provide more insight in the association between behavioural symptoms and the differences between children that do and do not get special services. The results indicate that more support is sought for children with DCD who, compared to their DCD peers have poor quality of gross motor patterns, poor ball skills and balance, better manual dexterity, and less internalizing behaviour. Van Enk found that besides health-need symptoms, the only parental non-somatic factor that influences the chance of use of health-care services is a mothers’ propensity to seek lay-advice.10 The more a mother contacts her social network, the higher the chance that she will visit a GP with her child. 10;23 In the advice from lay-persons, the quality of a child’s motor patterns might play an important role. The children who perform with a relatively high quality of movement patterns but with low accuracy and/or speed might be regarded by lay people as a developmentally delayed. People might think that a child will outgrow these problems. However, the motor performance of children with a poor quality of movement patterns often appears awkward to lay people. The awkward appearance might be interpreted as a disorder that needs remediation. Mandich et al. 2 found that a child’s inability to participate is a reason for parents to access special services. In our study, parents seem to have consulted a GP when their child is lacking gross motor skills, i.e. skills necessary to enjoy participating in playgrounds or sport settings. Still, the parents of the children in the non-referred group were having concerns. They did not consult a GP, but they did refer themselves to us. The willingness of these parents to participate in this study might be due to their need to share responsibility in the decision to seek/not seek help. Sharing responsibility is often an important cue to use healthcare services in childhood.10 The fact that children were not randomly selected through a screening and testing procedure might be interpreted as a limitation of our study. We did not randomly test children since such a procedure might lead to overidentification and possibly medicalisation because there is no sound test for criterion A with high specificity. It has to be noted that the often used M-ABC criterion does not imply that 15% of normal population has DCD. The actual incidence will be lower because the specifications of criterion B have to be met as well. i.e. the motor problems have to have an impact on tasks of daily living or school performance.5 Because the children were already referred


21 Chapter 2

to physiotherapy or parents responded to the poster themselves, they were aware of the motor problems in daily life, and the test results did not surprise them. Moreover, it was the problems experienced by the child and the parent(s) that initiated use of health services. Therefore, the perceived need is probably a better point of view than the (poorly) evaluated need.10 For clinicians, it is important to know that not the severity but the nature of the children’s motor difficulties seems to influence the parental perception to access treatment. Both groups in this study had motor difficulties that indicated physiotherapy. The non-referred group tended to internalize their problems more which might have made their problems in daily life less apparent for others, such as lay-persons, GPs, and health care specialists. We plead for a better identification of children with DCD, in school but also by health care workers. When parents are concerned about their child’s motor development, the child might thus not only be at risk for poor motor development but poor social-emotional development as well.

Acknowledgements We thank the children and their parents for being so willingly to participate in this study. We are also grateful to the paediatric physiotherapists who postponed the start of treatment in the referred group in order to make comparison with the children in the non-referred group possible. Thanks to Daphne Kuiper for providing reference data for the TGMD-2 in the Netherlands, and Janke Oosterhaven who has put a lot of effort in developing an ethical sound way to include children in the non-referred group.

References 1.Orton ST. (1937) Reading, writing and speed problems in children. NewYork: Norton. 2.Mandich AD, Polatajko HJ, Macnab JJ, Miller LT. (2001). Treatment of children with Developmental Coordination Disorder: what is the evidence? Phys Occup Ther Pediatr, 20:51-68. 3.Pless M, Carlsson M. (2000). Effects of motor skill intervention on DCD: a meta-analysis. Adapt Phys Act Q , 17:381-401. 4.Peters JM, Henderson SE, Dookun D. (2004). Provision for children with developmental co-ordination disorder (DCD): audit of the service provider. Child Care Health Dev , 30:463-479. 5.Geuze R, Jongmans MJ, Schoemaker M, Smits-Engelsman B. (2001). Clinical and research diagnostic criteria for developmental coordination disorder: a review and discussion. Hum Mov Sci, 20:7-47. 6.American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders (4th ed, text-revision.). Washington, DC: American Psychiatric Association. 7.Andersen RM, Newman JF. (1973). Societal and individual determinants of medical care utilization in the United States. Milbank Memorial Fund Q, 51:95-124.


22 5- Niemeijer - Chapter 2

8.Cunningham PH, Freiman MP. (1996). Determinants of ambulatory mental health services use for school-age children and adolesents. Health Serv Res, 31:409-27. 9.Niemeijer AS, Schoemaker MM, Smits-Engelsman BCM. (2003). Kinderen met een developmental coordination disorder: welke kinderen krijgen hulp in de eerstelijnskinderfysiotherapie? TvK [Journal of paediatric medicine], 71:197-202. 10.Van Enk JG. (2002). Determinants of use of healthcare services in childhood. Groningen, the Netherlands: PhD-thesis University of Groningen. 11.Henderson S, Sugden D. (1992). Movement Assessment Battery for Children; manual. Sidcup, Kent: The psychological Corporation. 12.Ulrich DA. (2000). Test of Gross Motor Development, Second Edition, examiner's manual. Austin, TX: Pro-Ed. 13.Achenbach TM. (1991). Manual for the Child Behavior Checklist/4-18 and 1991 profile. Burlington: University of Vermont. 14.Henderson S, Hall D. (1982). Concomitants of clumsiness in young school-children. Dev Med Child Neurol, 24: 448-60. 15.Lam J, Henderson SE. (1987). Some applications of the Henderson revision of the Test of Motor Impairment. Br J Educ Psychol, 57: 389-400. 16.Smits-Engelsman B. (1998). Nederlandse bewerking van de Movement Assessment Battery for Children (handleiding) [Dutch Manual]. Lisse, the Netherlands: Swets & Zeitlinger. 17.Leemrijse C, Meijer O, Vermeer A, Lambregts B, Ader HJ. (1999). Detecting individual change in children with mild to moderate motor impairment: the standard error of measurement of the Movement ABC. Clin Rehab, 13: 420-429. 18.Verhulst FC, Van der Ende J, Koot JM. (1996). Handleiding voor de CBCL/4-18. [Manual for the CBCL/4-18]. Rotterdam, the Netherlands: Academic Hospital/Sophia/ Erasmus University. 19.Smits-Engelsman BCM, Henderson SE, Michels CGJ. (1998). The assessment of children with developmental coordination disorders in the Netherlands: the relationship between the Movement Assessment Battery for Children and the Köorperkoordinations Test für Kinder. Hum Mov Sci ,17:699-710. 20.Smits-Engelsman BCM, Niemeijer AS, Van Galen GP. (2001). Fine motor deficiencies in children diagnosed as DCD based on poor grapho-motor ability. Hum Mov Sci, 20:161-182. 21.Crawford SG, Wilson BN, Dewey D (2001). Identifying developmental coordination disorder: consistency between tests. Phys Occup Ther Pediatr, 20: 29-50. 22.Kaplan BJ, Wilson BN, Dewey D, Crawford SG. (1998). DCD may not be a discrete disorder. Hum Mov Sci, 17:471-490. 23.McCue Horwitz S, Morgenstern H, Berkman LF. (1985). The impact of social stressors and social networks on pediatric medical care use. Med Care, 23:946-959.


Chapter 3 Neuromotor Task Training

for children with developmental

coordination disorder: a controlled trial

Anuschka S. Niemeijer Bouwien C.M. Smits-Engelsman

Marina M. Schoemaker

Developmental Medicine & Child Neurology 2007; 49: 406-411



24

Abstract The aim of this study was to evaluate neuromotor task training (NTT), a recently developed child-centred and task-oriented treatment programme for children with developmental coordination disorder (DCD). A treatment and a non-treatment control group of children with DCD were included. Children were selected if they scored below the 15th centile on the Movement Assessment Battery for Children (M-ABC). The children in the treatment group were recently referred for physiotherapy (n=26; 20 males, 6 females: mean age 7y 2mo [SD 1y 3mo]. The parents of the non-treated children (n=13) were concerned about their children’s motor performance and responded to advertisements for free testing (10 males, 3 females; mean age 7y 2mo, SD 2y1mo). Before and after nine weekly 30-minute sessions of NTT or at least 9 weeks of no intervention, the M-ABC and the Test of Gross Motor Development-2 (TGMD-2) were administered. Therapists reported per session on treatment goals and tasks trained. The effects on results indicate that motor performance does not improve spontaneously and that NTT is effective. During the intervention period, only the treated group improved on the M-ABC and the TGMD-2. Children improved most on tasks similar to those trained. In older children with poorer motor patterns, NTT’s treatment success was higher. The Child Behaviour Checklist subscales withdrawn, thought problems, anxious/depressed, and delinquency were determinants of effects on motor patterns.

A CONTROLLED TRIAL


25

pproximately 5 to 10% of schoolchildren have difficulty learning motor skills.1 A child is diagnosed with developmental coordination disorder (DCD) if the performance in daily activities that require motor coordination is substantially

below that expected given the child’s chronological age and intelligence, in the absence of any known neurological disorder or pervasive developmental disorder (PDD).2 To diagnose a child as having DCD, inadequate proficiency in movement performance should negatively interfere with activities of daily life.2 This latter criterion and the fact that most children do not outgrow DCD, which can have potentially long-term consequences,3;4 support the need for intervention. Evidence is lacking for the efficacy of treatment approaches that concentrate on the deficits in processes assumed to underlie poor motor coordination, such as sensory integration therapy and kinaesthetic training.5;6 For a decade, more task-oriented approaches have been emphasised and reveal promising results. These approaches focus directly on the functional skills hindering the child. Because only few studies have investigated task-oriented approaches, more efficacy research is needed. In the Netherlands, neuromotor task training (NTT) has recently been developed especially for children with DCD, because the existing intervention programs show no or little effect, and are not explicitly developed for these children.7;8 Until the introduction of NTT, Dutch therapists eclectically used what they had learned on various courses.9 NTT is based upon a cognitive neuroscience approach to motor control, which implies that several cognitive and motor control processes can be distinguished during the preparation and execution of functional motor tasks, such as the processing of motor-task related information, action planning, and initiation. Before starting the intervention, paediatric physiotherapists talk with the parent(s) to get insight into the problems experienced in daily life. In addition, they perform a standard protocol to assess the strengths and weaknesses of a child's functional performance. The aim of this assessment is twofold. First, the therapists determine the extent to which motor tasks are performed below the expected level, such as handwriting or ball skill tasks. Second, they will analyze which cognitive or motor control processes might be involved in the deficient motor performance. A child may fail to learn a specific motor skill because of attention problems, fear of failure, lack of motivation, or lack of understanding of how to execute a skill. In addition, motor control processes might hamper successful performance such as timing of components of a motor skill pattern, motor planning, or parameter setting (the execution of a motor act with the required speed and force). Thus the standard assessment of NTT includes the assessment of the child’s impairments within a particular functional motor activity. During intervention, therapists implement functional exercises that tap the specific motor control processes that are considered involved. NTT is a task-oriented approach focusing directly on teaching the skills a child needs in daily life. The higher the resemblance between skills

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and the circumstances practised during treatment and skills needed in daily life, the more transfer of skills can be expected. According to a recent review of treatment approaches, more recently developed approaches originate either from a dynamical systems approach or a cognitive neuroscience approach.10 Task-oriented approaches are generally based on dynamic systems theory. Although NTT is a task-oriented approach, the theoretical framework behind it differs from those behind other task-oriented approaches, such as the cognitive orientation to daily occupational performance (CO-OP) which was recently developed in Canada.11 In CO-OP, DCD is considered to be a motor learning disorder and cognitive strategies are taught to enhance motor learning. This contrasts with NTT, because NTT incorporates elements from the cognitive neuroscience approach and takes the motor training aspects into account as well. Although cognition plays a role in NTT treatment, for instance when therapists ask various questions about task performance, 7 cognitive strategies are not explicitly taught but tasks are trained in various, gradually more challenging, circumstances. This study examined the general effectiveness of NTT by means of a controlled trial in which motor performance was measured in a treatment and a non-treatment control group. In addition, we studied whether specific progress was made on tasks that resemble those trained. Furthermore, because DCD may not be a discrete disorder,12

the influence of behavioural characteristics on treatment success in the treatment group was investigated.

Method

Selection of participating children Treatment and a non-treatment control groups of children with DCD were included in this study. The non-treated group was used to control for possible testing effects and spontaneous development. The groups of children were not randomly selected because parents were unwilling to participate if their child had a chance of being put on a fictive waiting list. Moreover, because paediatric physiotherapists (PPTs) regard their services as effective, they felt it was unethical to withhold treatment when a child was referred to them. Forty therapists were willing to participate. They were instructed in NTT during their three-year training as PPTs, and during two extra meetings especially for this research. The fact that multiple therapists participated will enhance the external validity of our results. To insure internal validity homogeneous groups of children were compared since heterogeneity may obscure the effects reached in subgroups of children.9 All children in this study attended Dutch mainstream schools, which implies a normal-range IQ score.

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Thus far, Dutch children with serious learning difficulties (i.e. IQ < 80) attend special schools. The inclusion criteria were: (a) aged between 6 and 10 years; (b) no medical condition thought to have caused the motor problems; (c) no prior physiotherapy; (d) scoring at or below the 15th centile of the Movement Assessment Battery for Children (M-ABC);13 and (e) parental informed consent. The treated group consisted of children who were referred to physiotherapy by their general practitioner (GP) because of motor coordination problems in school and/or at home. They were checked by their GP and PPT for obvious neurological disorders and other medical conditions that could explain the motor difficulties. The control group was selected through posters in mainstream schools. We offered the opportunity to test unconditionally (and free of charge) children (ages 6-10y) whose motor abilities in daily activities were a point of concern for parents or teachers. To check for obvious neurological explanations of the motor problems, parents were asked whether the child had a history of accidents or physical traumas. If no obvious neurological disorder or other medical conditions were reported, the child was invited for two test occasions, each comprising of multiple tests within 3 months. A priori, for this controlled study, an average group difference of 5 points (about one SD)5,14 on the M-ABC was believed to indicate a significant group difference. This could mean change from the 5th centile to the 18th centile. Based on a 90% power to detect a significant difference between both groups with α being set at 0.05, the required sample size was 21 children per group. Sixteen children per group were required for 80% power. The Medical Ethics Committee of University Medical Center Groningen approved this study. In total, we included 20 males and 6 females scoring at or below the 15th centile on the M-ABC in the treatment group (n=26). They were treated by 13 PPTs. Their mean age was 7 years 2 months (SD 1y 3mo) range 6 years 2 months to 10 years 2 months. In the non-treatment control group, 13 out of 19 children tested were included because they scored at or below the 15th centile on the M-ABC at pretest: 10 males and 3 females (n=13), mean age 7 years 2 months (SD 2y 1mo), range 6 years to 10 years 7 months. Although the groups were not randomly selected, they did not differ in medical or social background, or age at which motor milestones were reached.15

Measurement Instruments General motor tests The M-ABC provides an indication of a child’s motor functioning in daily life.13 It gives an estimate of motor competence in terms of speed or accuracy (outcome of movement). This norm-referenced test consists of four age-related batteries, each having eight items measuring three different aspects of motor ability (subtests): manual dexterity, ball skills, and static/dynamic equilibrium. A lower score represents a better



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task performance. The total impairment score (TIS) can be converted into a centile score. A score less than the 5th centile indicates a definite motor problem and a score less than the 15th centile (less than one SD) indicates a degree of difficulty that is borderline.13 Leemrijse et al. studied the standard error of measurement (SEM) for different test items, subtests and the TIS.14 For the subtests, SEMs were 1.51, 1.73 and 1.84 respectively. The SEM for the TIS was 3.13 points whereas the mean ranged from 13.2 to 15.4, and the SD ranged from 3.9 to 7.5. Based on this SEM, an individual has improved significantly (95% confidence interval [CI]) if the TIS reduces at least 9 points.14 The second edition of the Test of Gross Motor Development (TGMD-2) is a criterion- and norm-referenced test designed to assess gross motor functioning of children aged 3 through 10 years.16 The test measures 12 gross motor skills that are usually acquired by children in pre-school and early elementary grades. Six of them form the locomotor (LM) subtest: running, galloping, hopping, leaping, horizontal jumping, and sliding. The other six form the object control (OC) subtest: striking, bouncing, catching, kicking, throwing, and rolling. Both subtest scores can be converted into a gross motor quotient (GMQ). A higher score indicates a better quality of movement pattern. A GMQ less than 85 indicates performance below the 15th centile. The SEM is 1 point for the subtests and 5 GMQ points for children above the age of 5.16

Treatment reports After each treatment session, therapists wrote a treatment report on the session goals and the skills trained. Therapists received at least nine sets of scoring sheets, all starting with the question: ‘Considering the reason to accessing special services, the goal of this session was…’. Subsequently therapists reported on the exercises the child had been practising. Afterwards, the researchers attempted to classify the skills trained into categories following the major categories of the M-ABC (manual dexterity, ball skills, balance) and TGMD-2 (LM, OC) as far as possible. In this way, we investigated whether children improved particularly on skills similar to those that were trained.

Behavioural characteristics To investigate whether behaviour characteristics influence the success of nine treatment sessions, the Child Behaviour Checklist (CBCL: Achenbach system of empirically based assessment)17;18 was administered. The CBCL is a parent questionnaire to assess problems in 4-to 18-year-olds. It contains 120 items on behavioural or emotional problems during the past 6 months. Data were entered in a special computer program through which t-scores could be obtained for eight problem syndromes, and internalizing and externalizing behaviour. The t-scores are corrected for age and sex, enabling comparisons with norm groups: t-scores above 60 (82nd centile) or 63 (90th

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centile) indicate behaviour in the clinical range.17;18 Parents received the questionnaires at the pretest.

Testing Procedure The researchers tested all children individually in a quiet room to determine current levels of motor performance. They were blind to treatment or control group. The M-ABC was administered first, to compare results with other studies using the M-ABC. Because Dutch healthcare insurers paid only for nine treatment sessions, children were retested after nine weekly half-hour treatment sessions, or in case of the non-treatment group after about 3 months without intervention. In practice, treatment sessions were frequently skipped because of holidays or illness, and nine treatment sessions took more than nine weeks.

Statistical analysis The data of the children in this study were not statistically independent as regular statistical techniques assume. The population of children consisted of subpopulations of therapists treating children with DCD. Therefore, we initially performed multi-level analyses.19 However, no strong hierarchical dependency was found. In our data, the variance at therapist level was 0 (SE=0), at the children’s level it was 25.3 (SE = 6.7) and within measurement occasions the variance was 22.3 (SE = 3.4). In other words, we found no effects of therapists on individual performance. Thus, the assumption of independent data does not seem to be violated if a general linear model is used. Subsequently, a 2x2 repeated-measurement analysis was used with pretest and posttest as within-subject factor, and group as between-subjects factor. This analysis uses difference scores, which is appropriate for non-random samples. Time differences between both test occasions was not controlled for because low associations were found between ‘weeks’ and ‘gain on the M-ABC’ (rs = -0.32) and ‘gain on the TGMD-2’ (rs = -0.03). Moreover, adding the ‘number of weeks between measurement occasions’ as a covariant did not reveal different results. Odds ratios were calculated to compare the proportions of children whose score was better versus worse in both groups.20 Differences between groups do not show how many treated children improved. While performing statistics at group level, the random mean measurement error will approximate to zero. This is not the case when investigating scores at the individual level. Therefore, the least detectable differences (LDDs) are calculated based on the SEMs published by Leemrijse et al.14 and Ulrich16 (taking %5 as significance level, the LDD = 1.96 * √2 * SEM). The individual (sub)test improvement was descriptively related to the classification of skills trained according to the treatment reports. Multiple linear regression was used to examine whether independent child-related characteristics influenced the treatment success. The change in motor performance (posttest [2] minus pretest [1]) was the dependent variable. In the first analysis, child



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characteristics (sex, age, and pretest scores) were the predictors, and in the second and third analyses, the predictors were the child-related CBCL-scores. In order to keep the regression coefficients (B) interpretable, the CBCL-scores were centred by subtracting their mean score.

Results Table 1 shows the group means for both motor tests during pretest and posttest. On the M-ABC, no pretest differences between groups were found (F(1,37)=1.18, p=0.28). During the intervention period the M-ABC scores changed statistically significant (F(1,37)=9.91, p=0.003). The treatment group improved on average nearly 6 points, whereas the control group’s average score did not show change. For the TGMD-2, the pretest scores of both groups differed by about 15 points (95% CI 5.3-23.3; t(37)=3.21, p=.003). The motor patterns of the treated group could be described as poor while those of the control group were average.16 After the intervention period, the quality of the treated group’s motor patterns had improved, whereas the performance of the control group had deteriorated (F(1,37)=16.25, p< 0.001; Table 1). Table 1. Group mean scores (and SD) at pretest and posttest on two general motor tests Group Pretest Posttest

Treated with NTT 17.7 (5.5) 11.8 (7.4) M-ABC Non-treated control 16.7 (5.4) 17.0 (7.5) Treated with NTT 75.8 (12.0) 83.2 (11.2) TGMD-2 Non-treated control 90.0 (15.3) 79.3 (17.7)

M-ABC, Movement Assessment Battery for Children;13 TGMD-2, Test of Gross Motor Development-2 16, NTT, neuromotor task training

Figure 1 shows that only one child in the treated (referred) group deteriorated (depicted in the lower-right quadrant), whereas in the control group only one child improved (upper-left quadrant). Children in the treated group were more likely to improve on the M-ABC (odds ratio [OR] 3.89; 95% CI 0.94-16.1) and the TGMD-2 (OR 26.7; 95% CI 2.88-248) than children in the non-treatment group. The treated child who did not show any improvement on either test was treated to improve his writing skills. Special attention was paid to the difficult curvature of some letters, and the speed accuracy aspects of the child’s writing. Writing is not evaluated with M-ABC’s manual dexterity items.21 This child deteriorated 0.5 M-ABC points and 6 points on the TGMD-2.

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In the treated group, 10 individuals improved more than the least detectable difference (LDD) of 9 points on the M-ABC and eight improved one LDD or more on the TGMD-2. None of the control children improved one LDD or more on either test (Table 2). Table 2. Number of children who changed one least detectable difference (LDD) or more Group Improved

≥ 1 LDD Stable < LDD >

Worsened ≤ 1 LDD

Treated with NTT 10 16 0 M-ABC Non-treated control 0 13 0 Treated with NTT 8 16 2 TGMD-2 Non-treated control 0 8 5

M-ABC, Movement- Assessment Battery for Children;13 TGMD-2, Test of Gross Motor Development-2;16 NTT, neuromotor task training.

Figure 1: Plot of individual difference scores. Children with positive effects of therapy on both test are plotted in the upper-left quadrant; children who performed worse on both tests after intervention are plotted in the lower-right quadrant. M-ABC, Movement Assessment Battery for Children;13 TGMD-2, Test of Gross Motor Development-2.16



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Treatment group Treatment reports were lacking for two of the 26 children. These children initially performed poorly on both tests. For the other 24 children, therapists had pursued one or more treatment goals that were concordant with at least one of their individual poor pretest scores. Not all skills that were performed poorly on the pretest were made into explicit treatment goals by the therapists (Table 3). Conversely, some goals were pursued while the child had performed that skill within test norms. In these cases, no or little improvement could be expected with both tests used. Moreover, the LDD often is equally high or higher than the 15th centile cut-off score, rendering significant improvement mathematically impossible.13

Table 3 shows the number of children whose performance score was improved at least one LDD, stable, or worsened one LDD or more. Children especially improved their test scores if they had been training similar tasks during NTT (3-7 out of 12-17 children with poor performance). If they had not trained the skills necessary to perform the tasks tested or their performance was already within age norms, performance was often stable. Only two children improved significantly on tasks that were not explicitly trained according to the treatment reports. Both had improved their static/dynamic equilibrium. The results in Table 3 do not indicate that certain motor skills are more easily improved by treatment than other skills. Table 3. Number of treated children whose posttest performance scores were improved (I), the same (S) or Worse (W) for different subtests and given the pretest performance and goal of treatment Performance below 15th centile

(<1 SD) Performance within norms

goal no goal goal no goal I S W I S W I S W I S W M-ABC Fine motor skills 3 9 0 0 3 0 0 4 0 0 5 0 Ball skills 6 8 1 0 1 0 0 1 0 0 7 0 Balance 3 12 0 2 0 0 0 5 0 0 2 0 TGMD-2 LM skills 7 8 0 1 1 0 0 2 0 0 5 0 OC skills 5 12 0 0 2 0 0 1 0 0 4 0 M-ABC, Movement -Assessment Battery for Children;13 TGMD-2, Test of Gross Motor Development-2;16 LM, locomotor; OC, object control

The M-ABC difference scores of the treated children were predicted by neither sex (p=0.50) nor age (p=0.70). Nor could the gain on the TGMD-2 be explained by sex (p=0.57). However, older children improved more on the TGMD-2 (regression

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coefficient B for age in months = 0.51, p=0.01) when adjusted for the children’s initial TGMD-2 scores (B =–1.04, p<0.001). This finding indicates that besides age, poor initial motor patterns were associated with more improvement. For the M-ABC, no such association was found (p=0.25). Within the control group no associations between pretest and difference scores were found (for TGMD-2: B=-0.25, p=0.28; for the M-ABC: r=0.30, p=0.12, both adjusted for age). Table 4 shows that the children in the treated group scored highly on social and attention problems. These behaviour characteristics did not influence the treatment success. Children who were more withdrawn and/or who had more thought problems improved less. A child who, for example, scored one point higher on the withdrawn subscale improved 1.17 [B =-1.17; 95% CI -2.22 to -0.12] points less on the TGDM-2. More positive effects of treatment were found for children who were more anxious/depressed and/or who exhibited higher scores for delinquency. Neither ‘internalizing’ nor ‘externalizing’ behaviour could predict the effectiveness of NTT (Table 5). Table 4. Regression Coefficients [and 95% confidence intervals] between eight sections of CBCL (centred) and effectiveness measures CBCL Mean, range M-ABC 2-1 p-value TGMD-2 2-1 p-value

Overall mean -5.74 [-8.72,-2.77] .01 7.86 [2.72, 13.01] .05 Withdrawn 58, 50-73 -0.51 [-1.12, 0.10] .093 -1.17 [-2.22, -0.12] .031 Physical complaints 56, 50-74 0.24 [-0.35, 0.83] .40 -0.63 [-1.65, 0.39] .21 Anxious/depressed 57, 50-77 0.27 [-0.45, 0.99] .44 1.48 [0.23, 2.72] .023 Social 64, 50-88 0.082 [-0.49, 0.66] .76 0.89 [-0.10, 1.77] .076 Thought 56, 50-75 -0.089[-0.71, 0.53] .77 -1.14 [-2.21, -0.06] .039 Attention 63, 50-80 -0.29 [-1.02, 0.43] .41 -1.20 [-2.46, 0.05] .059 Delinquency 56, 50-77 0.004 [-0.70, 0.71] .99 1.76 [0.54, 2.98] .008 Aggressive 57, 50-84 0.44 [0.10, 0.97] .10 0.10 [0.82, 1.02] .82 CBCL, Child Behaviour Checklist;17 M-ABC 2-1, (posttest minus pretest) Movement Assessment Battery for Children;13 TGMD-2 2-1, (posttest minus pretest) Test of Gross Motor Development-2. 16

Table 5. Regression Coefficients [and 95% confidence intervals] between two major scales of CBCL (centred) and effectiveness measures CBCL Mean, range M-ABC 2-1 p-value TGMD-2 2-1 p-value

Overall mean -5.90 [-8.70, -3.10] .0001 7.86 [1.79, 13.79] .05 Internalizing 55, 34-74 -0.04 [-0.34, 0.26] .78 0.210 [-0.49, 0.81] .32 Externalizing 54, 32-83 .0.19 [-0.10, 0.48] .18 0.218 [-0.44, 0.80] .30 CBCL, Child Behaviour Checklist;17 M-ABC 2-1, (posttest minus pretest) Movement Assessment Battery for Children;13 TGMD-2 2-1, (posttest minus pretest) Test of Gross Motor Development-2. 16



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Discussion The aim of this study was to evaluate NTT, a new treatment programme for children with DCD. The number of children included in the study was sufficient to prove that NTT is successful. Results showed that the treated group improved on both tests compared with the non-treated control group. More specifically, the non-treated group’s M-ABC score was stable, whereas their TGMD-2 score had deteriorated. The results add to the knowledge that task-oriented treatment approaches can have positive effects on children with DCD.5 They also show that spontaneous development within a 3- to 4-month period is rare in children with DCD.3;4 As in most recent studies on DCD, the M-ABC was used to select children with DCD,1 and to measure changes in performance. One could therefore argue that the reported effects of therapy are the result of ‘regression to the mean’. From this viewpoint, it is noteworthy that the non-treated control group did not spontaneously improve on the M-ABC. Moreover, their initial TGMD-2 scores were not related to change, whereas these scores had predictive value for the treated group. This indicates that the improvement is due to NTT. For this naturalistic study no restrictions were made about treatment schedules, so results are representative of daily practice in which variation in therapy provision is common. The fact that several therapists participated and that they were unaware of the children’s pretest performance suggests a wide effect of NTT. Although they may also have used the M-ABC, the TGMD-2 was unknown to them. They made their rehabilitation plans entirely independently from the researchers’ findings, based on their own assessment and problems experienced by the individual child in daily life. Clinically significant improvement (one LDD or more) was found most frequently in subtests that measured motor performance with tasks similar to those trained during NTT. Individual improvement was measured with LDDs to account for measurement error (a low test-retest reliability). For example, our post-pretest scores range from –7 to +7 for the M-ABC. Although the LDD is a conservative measure,14 more than half of the children were able to reach a difference score of at least one LDD on one or both tests. If similar tasks were not trained, a significant treatment effect was not likely to occur. These results suggest that treatment should be task specific in order to help children with DCD conquer their problems in daily life. Moreover, these results indicate that the positive effects of NTT are not (only) due to attention or other Hawthorne effects. Some children improved on balance tasks whereas no such tasks were reported as being trained. Although transfer to untreated skills has been reported earlier9, it is likely that balance was trained as an intrinsic part of other skills. However, it is also possible that other processes were initiated by this study or NTT too: children could have become more motivated to perform well during the test, gained self-confidence, or participated more in physical activities affecting their motor performance.

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Some child characteristics were studied in relation to the treatment effects. Within the treated group, males and females were similarly affected by therapy. No age effects were found on the M-ABC gain. In other studies using the M-ABC, therapy has been found to have better effects on children aged 6 to 13 years.6 This study’s small age range (6 to 10y) might thus explain the ability to find positive treatment effects and the lack of age effects on the M-ABC gain. Still, age did predict the TGMD-2 gain. In the treated group, older children improved their movement patterns the most. In these analyses, we controlled for pretest scores. Therefore, confounding by indication is no explanation for this age effect. Another explanation might be found in the way therapists teach. During NTT, therapist share knowledge about movement tasks and execution.7 They talk, for example, about why it is better to perform in a certain way, or ask a child whether he or she understands the task. It could be that improving children’s movement patterns is easier if they are old enough to understand and reflect on their own performance. Because child-related behavioural characteristics might obscure NTT’s effectiveness, other variables were examined as well. In addition to the findings of Schoemaker et.al.9 the present TGMD-2 results show that severity can be predictive for treatment success. Although several behavioural and emotional problems are associated with DCD,12 CBCL scores were not associated with M-ABC gain and only slightly associated with TGMD-2 difference scores. It is unclear why these relations were found. More research into these child-related characteristics is necessary, as it might have clinical relevance and might be the next step to improve treatment programmes. However, because the associations were low, the present findings indicate that therapists are able to take children’s emotional and social behaviour into account in such a way as to reach positive treatment effects.

Acknowledgements We thank the therapists who treated the children. After each session they wrote the treatment reports. Moreover, they provided the researchers with the opportunity to test the children before treatment started in their own practices. And, of course, great appreciation goes to all the parents and children participating in this study.

References 1. Geuze RH, Jongmans MJ, Schoemaker MM, Smits-Engelsman BCM. (2001) Clinical and research diagnostic criteria for developmental coordination disorder: a review and discussion. Hum Mov Sci 20: 7-47. 2. American Psychiatric Association. (2000) Diagnostic and statistical manual of mental disorders (4th ed, text revision.). Washington, DC: American Psychiatric Association.



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3. Losse A, Henderson SE, Elliman D, Hall D, Knight E, Jongmans M. (1991) Clumsiness in children -do they grow out of it? A 10-year follow-up study. Dev Med Child Neurol 33: 56-68. 4. Christiansen SA. (2000) Persisting motor control problems in 11- to 12-year-old boys previously diagnosed with deficits in attention, motor control and perception (DAMP). Dev Med Child Neurol 42: 4-7. 5. Mandich AD, Polatajko HJ, Macnab JJ, Miller LT. (2001) Treatment of children with Developmental Coordination Disorder: what is the evidence? Phys Occup Ther Pediatr 20: 51-68. 6. Pless M, Carlsson M. (2000) Effects of motor skill intervention on DCD: a meta-analysis. Adapt Phys Act Q, 17: 381-401. 7. Niemeijer AS, Smits-Engelsman BCM, Reynders K, Schoemaker MM. (2003) Verbal actions of physiotherapists to enhance motor learning in children with DCD. Hum Mov Sci 22: 567-581. 8. Schoemaker MM, Smits-Engelsman BCM. (2005) Neuromotor Task Training: a new approach to treat children with DCD. In Sugden DA., Chambers M, eds. Children with Developmental Coordination Disorder. London: Whurr. p. 212-227. 9. Schoemaker MM, Hijlkema MGJ, Kalverboer AF. (1994) Physiotherapy for clumsy children: an evaluation study. Dev Med Child Neurol 36: 143-155. 10. Wilson, P.H. (2005) Practitioner review: approaches to assessment and treatment of children with DCD: an evaluative review. J. Child Psychology and Psychiatry 46: 806-823. 11. Mandich AD, Polatajko HJ. (2005) A cognitive perspective on intervention for children with Developmental Coordination Disorder: the CO-OP experience. In: Sugden DA, Chambers M, eds. Children with Developmental Coordination Disorder. London: Whurr. p.228-241. 12. Kaplan BJ, Wilson BN, Dewey D, Crawford SG. (1998) DCD may not be a discrete disorder. Hum Mov Sci 17:471-490. 13. Henderson SE, Sugden DA. (1992) Movement Assessment Battery for Children; manual. Sidcup, Kent: The Psychological Corporation. 14. Leemrijse C, Meijer OG, Vermeer A, Lambregts B, Ader HJ. (1999) Detecting individual change in children with mild to moderate motor impairment: the standard error of measurement of the Movement ABC. Clin Rehabil. 13: 420–429. 15. Niemeijer AS, Schoemaker MM, Smits-Engelsman BCM. (2003) Kinderen met een developmental coordination disorder: welke kinderen krijgen hulp in de eerstelijnskinderfysiotherapie? Tijdschrift voor kindergeneeskunde [Journal of paediatric medicine] 71: 197-202. 16. Ulrich DA. (2000) Test of Gross Motor Development, Second Edition, examiner's manual. Austin, TX: Pro-Ed.

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17. Achenbach TM (1991) Manual for the Child Behavior Checklist/4-18 and 1991 profile. Burlington: University of Vermont. 18. Verhulst FC, Van der Ende J, Koot JM. (1996) Handleiding voor de CBCL/4-18. [Manual for the CBCL/4-18]. Rotterdam, the Netherlands: Academic Hospital/Sophia/Erasmus University. 19. Snijders TAB, Bosker RJ. (1999) Multilevel Analysis: An Introduction to Basic and Advanced Multilevel Modeling. London / Thousand Oaks / New Delhi: Sage. 20. Altman, D.G. Practical Statistics for medical research. London: Chapman & Hall, 1997. 21. Smits-Engelsman BCM, Niemeijer AS, Van Galen GP. (2001) Fine motor deficiencies in children diagnosed as DCD based on poor grapho-motor ability. Hum Mov Sci 20: 161-182.



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Chapter 4 Verbal actions of physiotherapists

to enhance motor learning in children with DCD

Anuschka S. Niemeijer

Bouwien C.M. Smits-Engelsman Koop Reynders

Marina M. Schoemaker

Human Movement Science 2003; 22: 567-581



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Abstract In this study, the motor teaching principles taxonomy (MTPT) was developed to investigate which teaching principles physiotherapists use to treat children with developmental coordination disorder during Neuromotor Task Training (NTT). In NTT, special attention is paid to the best ways to instruct and provide feedback. Based on motor learning theory and video observations of NTT treatments, teaching principles aimed at improving motor learning were categorised into three categories: giving instruction, providing or asking feedback, and sharing knowledge. The MTPT’s reliability and validity were satisfactory. Therapists gave instructions very frequently. In addition, the principle frequency showed hardly any correlation with the children’s initial motor performance level, indicating that the principles used are not related to the child’s entry level.

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he essential feature of developmental coordination disorder (DCD) is a marked impairment in the development of motor coordination (Diagnostic and statistical manual of mental disorders 4th edition, American Psychiatric

Association, 1994). DCD can be apparent in a variety of skills that require actions of the motor system. The level of motor coordination is below that expected given the child’s chronological age and intelligence, in the absence of any known neurological disorder, and leads to problems in daily life activities, which include playing and academic performance. There is a great need for treating this disorder because most children do not outgrow DCD (Cantell, Smyth, & Ahonen, 1994; Christiansen, 2000; Geuze & Borger, 1993; Hellgren, Jilbergt, Gillberg, & Enerskog, 1993; Losse et al., 1991), and it can lead to several long-term consequences such as an increase in medical events, less interest in sports and social problems (Henderson & Hall, 1982). Several approaches are used to treat children with DCD, as no single approach works for everyone due to the heterogeneous symptoms of DCD (Wallen & Walker, 1995). For many years now, the main treatment objectives have been to remediate underlying processing deficits and facilitate neuro-maturational development. The effectiveness of these bottom-up approaches, like Sensory Integration Therapy, perceptual-motor training or kinaesthetic training, has been studied. Mandich, Polatajko, Macnab, and Miller (2001) concluded in a review study that no bottom-up approach was reliably better than no treatment at all, and suggested that the positive effects found in evaluation studies could be explained by simple maturational effects. As children with DCD by definition have problems with performance in daily activities, more functional treatment approaches have been emphasised (Mandich et al., 2001). It is obvious that children with DCD fail to acquire skills that many children learn informally and perform without close attention (Henderson & Henderson, 2002). Therefore, in the more recently developed top-down approaches, the main objectives of treatment are formal tuition and skill acquisition. Therapists become teachers who guide the child in the process of learning motor skills. Evidence for the effectiveness of these approaches is just now becoming available (Polatajko, Mandich, Miller & Macnab, 2001; Schoemaker, Niemeijer, Reynders, & Smits-Engelsman, in press; Smits-Engelsman, Niemeijer, & Van Galen, 2001). An example of a top-down approach is the recently developed Neuromotor Task Training (NTT). Schoemaker et al. (in press) showed that treatment according to NTT has positive effects on handwriting and on fine and gross motor skills that were measured with the M-ABC tasks. NTT incorporates several principles derived from motor control and motor learning research (Schmidt & Lee, 1999). It is a child-centred intervention focused on treating functional motor skills. While it is a mainly task-oriented method, motor control processes are analysed and trained during practice. A great deal of attention is also given to motor teaching principles. Research has shown that applying the most effective teaching principles can enhance motor learning in

T



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general and transfer in particular. The influence of the therapist may be especially significant in top-down approaches such as NTT, where the therapist must give the formal tuition. Therefore, while treatment approaches tend to only describe in detail the motor control theories on which an approach is based, NTT also instructs therapists about the best ways to instruct or to provide feedback. The primary aim of this study was to develop a motor teaching principles taxonomy (MTPT) in order to investigate what teaching principles therapists trained in NTT actually used in daily practice. Even though the participating therapists all provided treatments based upon NTT, they were likely to have different styles for tutoring children. In order to gain insight into whether therapists applied the teaching principles they had learned, treatment sessions were recorded on videotape. With the MTPT, the therapeutic actions (i.e., those aimed at improving motor learning) could be classified during such observations. In this paper we describe the developmental process of this taxonomy as well as the reliability and preliminary validity of the MTPT.

Method

Intervention The Neuromotor Task Training treatment programme is taught in today’s curriculum for paediatric therapists in the Netherlands. It is mainly task-specific or skill-based, which means its focus lies on direct teaching of the tasks to be learned. The choice of tasks depends on the individual needs of the child as well as on the expectations, capabilities and motivation of the child and the parents. By increasing the level of difficulty within the same functional task, this form of training is expected to have a higher transfer to daily activities. Within the NTT approach, physiotherapists start by assessing the strengths and weaknesses of a child's functional performance. The entrance level of training a skill is determined by loading various aspects of the task performance. In goal directed movements, this could be speed or accuracy in relation to distance and target size. Paediatric physiotherapists design the functional exercise in such a way that they can analyse which motor control processes are deficient. For instance, if providing a secure and supportive surrounding improves ball catching, task training will aim at more psychological processes. If, however, a child can catch the ball only when standing still and is warned beforehand, ball catching in complex and attentionally demanding situations will be trained. If the child has not yet developed a throwing pattern, the opportunity of merely throwing a variety (size, weight, material) of objects will be given. A demand on parameterisation will gradually be introduced later, by propelling the object over various distances or by aiming the objects at targets of different sizes. Through NTT, functional skills are trained in such a way that they tap the specific motor control processes that are thought to be involved.



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The therapists received additional training in applying effective motor learning principles, on how to give instructions and provide feedback during their treatment of children. In their textbook on motor control and learning, Schmidt and Lee (1999) discuss ‘prepractice conditions’ in which motor learning can be enhanced when the child is not directly engaged in practice. These conditions involve learning motivation (goal setting) and provision of verbal information. The NTT program pays special attention to how therapists teach a child a skill. Future NTT therapists are taught to choose between different learning options, such as implicit, guided discovery or explicit learning. The process of learning complex skills shows multiple phases or stages of explicit learning: the cognitive phase, the associative phase and the autonomous phase (Fitts, 1964). It prioritises giving the child some sort of ‘idea’ or image of the task to be learned, be it through verbal instructions, use of videotapes and/or demonstrations. According to Schmidt and Lee (1999), clear instructions about what task to perform, how to perform it, and what to attempt to achieve as a score, are critical for motor learning. Less effective is the instruction ‘go’. Therapists should therefore give instructions (clues) that provide useful and important information about the movement itself, such as the initial positions relative to the surroundings. Instructions can also stress ways to recognise one’s own errors. After performing a motor task, providing feedback about what was done may be essential for skill learning. Therapists can talk about the outcome of movement (results) or about the nature of the movement pattern (performance). Providing adequate feedback on performance may enhance motor learning, especially in children with motor problems. Furthermore, in NTT both the motivational and informative functions of feedback are emphasised. The paediatric physiotherapists willing to participate in a research study on the effectiveness of NTT learned NTT during their three-year training as PPT and two extra meetings especially for purposes of this research. During the first meeting, an update was given on NTT. Then therapists recorded a treatment session on videotape while treating the child according to NTT principles. At the second meeting the tapes were brought in, and were used to develop a critical approach to the therapists’ habits and to stress the NTT principles in their treatments. Tapes were randomly started and stopped after approximately 2 min. All kinds of questions were asked, such as ‘why do they practice these skills?’, ‘what could be the reason these skills were trained?’, ‘what does the child think after the remarks the therapist made?’, ‘what would you say to this child?’. The group size of no more than 10 therapists allowed for exploration of such questions and all possible answers.

The development of a motor teaching principles taxonomy A motor teaching principles taxonomy was developed to classify overt and directly observable therapeutic actions, that is, actions by therapists aimed at enhancing motor



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learning. MTPT serves as an instrument to analyse video recordings of the treatment of children with DCD by physiotherapists trained in NTT. It is more than just a description of actions by therapists, because it combines theory and practice. The taxonomy is the final result of a cyclical process that incorporated knowledge from motor learning research as was emphasised in NTT (see section on intervention) and the observation of therapeutic actions on videotapes.

The developmental procedure of the MTPT The development of the taxonomy was a two-sided procedure: it was necessary to adopt a theoretical framework in order to subsequently observe in practice the situation in which the taxonomy would be used. Theory and practice overlapped as long as was necessary to develop a theory-driven instrument. Recent knowledge on motor learning, such as how to give instructions or feedback to children, were the building blocks for the teaching principles formulated in NTT. This knowledge guided the researchers in developing the taxonomy. To begin with, Schmidt and Lee’s definition of motor learning was adopted (‘motor learning is a set of internal processes associated with practice or experience leading to relatively permanent changes in the capability of motor skill’, 1999, p. 264). To find out what therapist behaviour could be seen as representative for this motor learning, the researchers watched video recordings, made by the therapists who brought them in for their NTT training. The researchers made an inventory of all deliberate actions by the therapists that seemed overt to people watching the video recordings, and which were assumed to aim at realising relatively permanent changes in motor performance. Thus talking about the weather or doing math were not considered to improve motor learning, although small talk can provide a nice working atmosphere that might help a child’s motivation to learn. As a result, mainly therapeutic verbal actions (purposeful and deliberate verbalisations) were registered, such as ‘make a little basket of your hands when catching the ball’, ‘try to touch my hand with your head’, ‘try not to make a loud noise when you land on the floor’, or ‘very good’ and ‘okay’. Manipulations of body parts and physical demonstrations could also be observed directly and were registered. The result of this developmental preparation phase was a long list of observed therapeutic actions. In the following phases, all observed and listed actions were clustered into one teaching principle if they were similar. For example, ‘try to jump twice’ or ‘throw the ball’ were considered as one teaching principle that was named ‘giving commands’. This clustering process was guided by the researchers’ knowledge of motor learning. The teaching principles, clusters of therapeutic verbal actions, were labelled by active voice without theoretical terms. This made the observations easier, because the principles refer directly to what happens. After this clustering process, the distinctions in NTT between ‘giving instruction’ and ‘providing feedback’ were used to categorise the



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principles. At the end of the procedure we can distinguish three levels in the MTPT. At the highest level, we find classes of therapeutic behaviour close to the definition, hence to the ‘theory’ of Schmidt and Lee (1999). At the second level we find smaller parts of these behavioural patterns – the motor teaching principles. And on the third level we find the concrete verbal actions aimed at enhancing motor learning in children during a treatment session.

Analyses of the psychometric quality of MTPT The psychometric requirements of a classification scheme include completeness, mutual exclusiveness, reliability and validity (Reynders, 1992). • The completeness requirement refers to whether all possible verbal actions aimed at enhancing motor learning observed by the researchers were covered by a teaching principle. To this end, six other video recordings brought in by therapists for their final instruction in NTT were observed and analysed with the Noldus software program Observer 4.1. Whenever the principles did not cover all actions, new principles would be created. • Mutual exclusiveness was reached when a therapeutic action could be covered by only one teaching principle and could thus be classified in only one category of the taxonomy. An indication for this requirement was obtained by reliability measures. • Reliability was measured through intrarater and interrater reliability measures. The agreement was corrected for chance using Cohen’s kappa. A value above 0.60 is regarded as satisfactory (Van de Sande, 1999). Intrarater reliability (consistency of observations) was assessed by comparing two observations with an interval of at least one week, and interrater reliability (objectivity of observations) was assessed by comparing observations of the tape by the research assistant and the first author of this paper. • The MTPT is face-valid because the taxonomy does not predict a construct but describes the actions directly (Nunnaly, 1967). The validity of the MTPT will be good if no extension of the teaching principles or categories is required for the observation of other video recordings of NTT treatment sessions (see completeness). It is also important that the interpretations of the data gathered with the MTPT be valid. The primary aim of the MTPT was to investigate what teaching principles therapists trained in NTT actually use to enhance motor learning in children with DCD. In order to report valid frequencies for each principle, the researchers decided that whenever therapists repeated their action because the child did not react, this action was included in the analyses only once. The principles used by therapists could however be different due to differences between therapists or children. This could harm the validity of the interpretation of the frequency with which teaching principles are used. We therefore examined whether the MTPT frequencies observed during 30 min NTT sessions were associated with therapists’ age or the motor performance tests scores of the children



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with DCD. The existence of associations would indicate that the observed frequencies would have to be interpreted with care, because other therapists or the treatment of children with other motor performance levels would lead to different results.

Participating therapists The professionals participating in this study were registered in the Netherlands as paediatric physiotherapists. Instruction in Neuromotor Task Training was given to the therapists at the start of this study. Thirteen female therapists, aged 37-53, treated the children in the study.

Selection of participating children Twenty-three children were referred to physiotherapy by their general practitioner (GP) because of motor coordination problems in school and/or at home. This indicates that their poor motor coordination interfered with activities of daily living (Developmental Coordination Disorder, criterion B, DSM-IV, 1994). The paediatric physiotherapist examined each referred child with the General Psychomotor Assessment Protocol for DCD (Smits-Engelsman, Van Galen, & Schoemaker, 1997), in order to exclude obvious neurological disorders or other medical conditions that could explain the motor difficulties (criterion C, DSM-IV). This protocol included assessing the child with the M-ABC to identify whether performance was below the 15th percentile given his/her age (to check for criterion A, DSM IV). A child was included in the study if both the GP and the physiotherapist agreed that he/she needed individual physiotherapeutic intervention, and if all criteria for developmental coordination disorder were met. Additional requirements for inclusion were attendance of a Dutch regular elementary school, implying an IQ-score in the normal range (criterion D), no history of physiotherapy, and parents’ informed consent. Eighteen boys and five girls with ages ranging from 5 to 10 were included. The mean age was 7 years 6 months (SD 1.1). The Medical Ethics Committee of Groningen University Hospital approved this study.

Protocol for extra video recordings As a video camera intrudes in the situation created by the therapist and child, only one treatment session was recorded on video. This was not done until the child had had six sessions and thus had become acquainted with the therapist, the room and the material. By this time, too, the therapist had set goals for the intervention. The therapists did not know what purpose the video recordings were to serve: they only knew that the researchers wanted to know more about what was actually practised during the sessions because the treatment was like a black box to them. The recordings showed therapists’ verbal and overt actions during one 30 min session.



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Tests of motor competence Although NTT is a task-oriented method, therapists tap the motor control processes that are assumed to be deficient while training functional skills. Only those skills are trained that needed training, or that child (and parents) wanted to be trained. Two tests of motor competence were used. A child was able to show his/her motor competence on a wide array of tasks (20).

The Movement Assessment Battery for Children, M‐ABC The M-ABC (Henderson & Sugden, 1992) is marketed by the Psychological Corporation in London. The test, which was validated for the Dutch population by Smits-Engelsman (1998), provides an indication of a child’s motor functioning in daily life. The M-ABC is a norm-referenced test consisting of four age-related batteries. Each battery consists of eight motor tasks; three items measure manual dexterity, two items measure ball skills and three measure static and dynamic equilibrium. A lower score represents a better performance. When a child is tested with the appropriate age-band and norms, a score at or below the 15th percentile means poor performance in comparison with his/her peers. In this study, the M-ABC was used by the therapists as an identification instrument for children with DCD, and as a research instrument by the researchers. This test is most often used to classify DCD and to measure effectiveness of treatment (Geuze, Jongmans, Schoemaker, & Smits-Engelsman, 2001). The standardised scores make comparisons within the broadest age range possible. The test is product-oriented as it measures motor competence in terms of speed and duration or the amount of successful attempts.

The Test of Gross Motor Development‐second edition, TGMD‐2 The TGMD-2 (Ulrich, 2000) is marketed by Pro-Ed, Texas. This test is a criterion- and norm-referenced test designed for the assessment of children aged 3 through 10. The instrument assesses gross motor functioning in two abilities: locomotor (LM) and object control (OC). For each of 12 skills, performance criteria were formulated and the observation of these leads to a raw score. A higher score indicates a better quality of movement patterns. The TGMD-2 provides several scores: raw scores, percentiles, age-equivalents, standard scores per ability, and a composite gross motor quotient (GMQ). The standard scores have a mean of 10 and a standard deviation of 3. Both standard scores can be converted into the GMQ, with a mean of 100 and a standard deviation of 15. The TGMD-2 (2000) possesses a high degree of reliability and little test error. Interscorer and stability-over-time reliability coefficients varied between r = 0.88 and r = 0.98 for both the LM and OC subtests and for the GMQ (Ulrich, 2000). In this study, the test is used because it measures 12 gross motor skills that are usually acquired by children in pre-school and early elementary grades. The test was also used because it is concerned with how the skill was performed, or the quality of movement patterns



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responsible for the performance outcome, rather than the product (Burton & Rodgerson, 2001). In addition, the norm-referenced standard scores make comparisons within the broadest age range possible.

Testing procedure The paediatric physiotherapists assessed the child for inclusion in this study. For objectivity reasons, a research assistant from the Institute of Human Movement Sciences also tested the children. Each child was tested individually at the therapists’ practices. Various motor tasks were used to determine the children’s current level of motor performance. Besides the M-ABC and the TGMD-2, which are used in this study, several grapho-motor tasks were administered. Depending on age, the total test battery took 90-120 min to complete. Younger children needed more time for each task and were given more time to rest in-between tasks to avoid worsening performance with fatigue. Even though the physiotherapist had already assessed the child with the M-ABC, the assessment was repeated. In this way, the obtained results were more likely to be true test scores, because huge learning effects on the M-ABC are reported for children with DCD (Leemrijse, Meijer, Vermeer, Lambregts, & Ader, 1999). The researchers administered the M-ABC first, so that the results could be compared with other studies using the M-ABC. Subsequently, the child sat at a table to do the experimental grapho-motor tasks on a digitizer for at least 10 min. After approximately 1 h of testing, the TGMD-2 was randomised with other grapho-motor tasks in such a way that the child was kept motivated and performed optimally.

Data analyses of test scores and MTPT frequencies To find out whether the motor teaching principles applied were associated with motor competence scores, correlations were calculated between MTPT frequencies, age of the therapists and scores on the tests administered by the researchers (M-ABC or TGMD-2). Spearman correlations were used because many principles were not normally distributed. For greater accuracy, the researcher analysed the correlations with scatterplots. In this study, many correlation coefficients were checked for significance. This might lead to capitalising on chance. However, because the small sample size would reduce the power, the significance level was set at 0.05.



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Results

The motor teaching principles taxonomy Table 1. The motor teaching principles taxonomy, three categories with principles covering verbal actions of physiotherapists aimed at improving motor learning

Giving instructions Giving information on what to do Give commands

Draw attention and demonstrate the movement Give clues on how to execute a movement Manually change the body in order to make a desired action possible

Sharing knowledge Talking about movement tasks and execution (before or during execution)

Explain why it is better to execute a movement in a certain way Revert to earlier trials Tell what the child is doing Provide rhythm or timing Explain the difficulty of a task Ask the child about the difficulty of a task Ask the child if he/she understands the task Ask the child if he/she thinks he/she can do the task (attainability) Ask the child questions about the movement execution of a task

Providing or asking feedback

Providing comments or asking for comments after the task is completed

Tell the child what was done right during the execution Tell the child what was done wrong during the execution Tell about the results of performance neutrally Tell about the positive results of movement Tell about the negative results of movement Ask the child’s opinion about the movement execution Ask the child’s opinion about the results of the task

To answer the question of which motor teaching principles were used by therapists to improve motor learning, all their overt actions were clustered into 20 principles. Some of these principles were difficult to categorise in either ‘giving instruction’ or ‘providing feedback’. Some therapists, for instance, explained why a movement should be executed in a certain way without directly telling the child that he/she should do it. This same kind of information was also observed after terminal feedback was given. Therefore another category was created, called sharing knowledge, which was often observed before or during the execution of a (new) practice trail. Therapists did not



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always provide feedback, they also asked the child to give feedback. The motor teaching principles taxonomy (see Table 1) thus contained 20 motor teaching principles in three major categories: (a) giving instruction to the child, (b) sharing knowledge with the child as part of the learning process, and (c) providing feedback or asking the child to give feedback. Table 2 shows that Cohen’s kappa for the intrarater or test-retest reliability was between 0.63 and 0.99, and for the interrater reliability between 0.60 and 0.77 for the three categories. For the separate principles all figures were 0.60 or higher, which is good (Van de Sande, 1999).

Table 2. Cohen’s kappa measures of reliability for three categories of the MTPT

Intrarater 1 Intrarater 2 Interrater 1-2 Giving instruction .69 - .79 .69 - .70 .64 - .68 Sharing knowledge .81 - .85 .73 - .85 .70 - .71 Providing or asking feedback .66 - .99 .63 - .90 .60 - .62

Results of observation of 23 tapes with the MTPT Table 3 shows that giving instruction was observed on average 37 times per session, SD 10.2 with a 23-56 range. Within this category many commands were given, 3-34 times in one session. Clues on how to execute a movement were observed once to 20 times. Sharing knowledge in the learning process was observed on average 20.9 times, SD 10.5 and 5-41 range. In this category, questions about how to execute a movement were observed most frequently. About the same amount of verbal actions were categorised as providing or asking feedback, mean 23.5 (9.3) with a 9-43 range. The feedback the children received generally concerned remarks about the positive results of their movement execution, on average 7.6 times in one treatment session. In addition, all therapists relayed positive results of the executed movements, with a range of 2–18 times. On the level of categories, the scores were all normally distributed. At the level of teaching principles they were either not skewed or skewed positively. Table 3 presents the frequencies of the different motor teaching principles and categories used. The observation of the 23 new video recordings that were made by the researchers after the final training in NTT did not reveal new actions. All observed verbal therapeutic actions fitted in the specially developed motor teaching principles taxonomy. Moreover, after observation of 23 videos, Cohen’s kappa for the intrarater or test-retest reliability was between 0.76 and 0.79 for the giving instruction category, 0.80 and 0.88 for the sharing knowledge category, and between 0.74 and 0.85 for the providing or asking feedback category.



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Table 3. Mean and range of number of times (frequency) that MTPT categories and principles were used, and correlation coefficients of MTPT frequencies with the children’s motor test scores Mean (SD) Range Correlation

with M-ABC Correlation with TGMD-2

Category: giving instruction 37.2 (10.2) 23-56 0.11 -0.15 Give commands 18.4 (7.8) 3-34 -0.05 -0.11 Demonstrate 3.5 (3.7) 0-13 0.14 -0.15 Give clues 12.7 (5.12) 1-20 -0.28 -0.27 Manually change body parts 2.7 (4.7) a 0-20 0.18 0.10 Category: sharing knowledge 20.9 (19.8) 5-41 0.15 0.14 Explain why 3.1 (3.2) 0-13 0.22 -0.22 Revert to earlier trials 2.9 (2.9) 0-12 -0.11 0.16 Tell what is being done 2.1 (2.3) 0-8 0.01 0.03 Provide rhythm/timing 0.1 (0.3) a 0-1 0.13 -0.14 Explain the difficulty 2.4 (2.6) 0-11 0.40 (.06) -0.25 Ask about the difficulty 1.4 (1.9) a 0-17 -0.03 0.12 Ask about understanding/comprehension

0.4 (0.7) a 0-2 0.32 -0.16

Ask about attainability 3 (2.9) a 0-12 -0.21 0.05 Ask about movement execution 5.6 (5.3) 0-18 0.09 0.28 Category: providing or asking feedback

23.5 (9.3) 9-43 -0.09 -0.19

Tell what went well 2.6 (2.1) 0-9 -0.25 -0.18 Tell what went wrong 2.2 (2.9) a 0-13 -0.12 -0.36 (.09) Tell about result neutrally 3.3 (3.2) 0-12 0.23 -0.12 Tell about positive result 7.6 (3.5) 2-18 0.06 -0.23 Tell about negative result 1.6 (1.3) 0-5 0.002 -0.003 Ask opinion performance 4.3 (4.3) a 0-15 -0.17 0.10 Ask opinion result 2.4 (2.4) 0-10 -0.19 0.30 Total verbal actions 81.8 (21.8) 39-128 0.17 0.02 p-values are provided in brackets when p < 0.10. a means not normally distributed.

Does the use of teaching principles differ with a child’s initial level of motor performance? The level of motor performance differed for the 23 children. All children were identified as performing ‘at risk/deviant’ (below the 15th percentile) during the physiotherapist’s assessment with the M-ABC. The researchers’ assessment showed that



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six children were scoring within normal on the M-ABC. The children’s mean total impairment score was 15.1 (SD 6.2), and their performance also varied on the TGMD-2, with a mean score of 73.4 (SD 12.3). Four children scored within normal limits on this test. In table 3, correlation coefficients are given for the association between the frequency of principles and the children’s test scores. These coefficients show that two teaching principles used by physiotherapists tended to be related to motor performance. Whenever a child performed more poorly on the TGMD-2, therapists were likely to provide more feedback on what went wrong (rs = -0.36, p = 0.09). If a child's performance was worse on the M-ABC, therapists would share knowledge about the difficulty of the task (rs = 0.40, p = 0.06). No significant correlation coefficients were found between frequencies of MTPT principles and the age of the therapists.

Discussion In this study, a motor teaching principles taxonomy was developed to investigate which teaching principles aimed at enhancing motor learning in children with developmental coordination disorder were used by physiotherapists during Neuromotor Task Training. NTT differs from many approaches because it pays special attention to teaching principles derived from recent motor learning research. During their training in NTT, therapists learned about different ways to instruct motor skills and provide feedback. Although the taxonomy was developed with these two teaching principles in mind, an additional category had to be created because several actions were ambiguous, e.g., ‘if you bend your knees, it’s easier’. These actions, in which therapists talk about movement tasks and movement execution with the child, could be observed before a new instruction was given (as feedback on previous performances), or during the execution of a movement. Therefore, all principles covering these actions were categorised as sharing knowledge. As a result of the developmental process, the MTPT consisted of 20 teaching principles in three categories: giving instruction, sharing knowledge, and providing or asking feedback. This last category contained feedback that was provided immediately after the child had executed a movement. It is referred to in research literature as final/terminal feedback. One might argue that the principles categorised in sharing knowledge are also forms of feedback, but then, the child could observe the provision of a repeated instruction in the same way. The MTPT was checked for several psychometric properties: completeness, mutual exclusiveness, reliability and validity. After it had been proved to be reliable, through Cohen's kappa measures for interrater and intrarater reliability, the researchers made several new video recordings of NTT treatment sessions. During observation of these videos with the MTPT, all therapeutic actions could be covered. The MTPT also works as a very complete taxonomy to classify verbal actions of therapists aimed at enhancing motor learning during NTT treatments of children with DCD. Because the MTPT



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allows the behaviour of therapists to be observed directly, and not by means of a psychological construct or through manipulation, it seems face-valid (Nunnaly, 1967). However, the actions observed were clustered into principles which may allow for observer interpretation, even though the naming of principles was done in verbs for a close relation with all possible verbal actions. Interrater and intrarater reliability measures on the frequencies of used principles and categories showed that they were obtained in an objective and reliable way. This last finding is very important because it provides evidence that the definition of each principle was clear enough to prevent individual observers from interpreting the actions as different principles. It also means that the principles and categories were mutually exclusive, and that the MTPT can be used to describe what teaching principles therapists trained in NTT actually use to enhance motor learning in children with DCD. Observation through the MTPT revealed that therapists used giving instructions most frequently. This means that children with DCD were encouraged to practice a lot during treatment sessions. According to Schmidt and Lee (1999), practice is very important for motor learning and therefore the number of practice trials should be maximised. Therapists have to give an instruction before a child with DCD knows what do. Fewer actions, however, were aimed at improving motor learning through sharing knowledge or providing or asking feedback. The frequency of most principles was normally distributed, indicating that a clear picture was obtained about what therapists do. Still, the principles showed great variations in minimum and maximum use. Consequently, even though the participating therapists all provided treatments based on NTT, they differed in their tutoring styles. The range of the number of principles frequently started at zero, indicating that those principles were scarcely applied. Only the three most frequently used principles were observed in each recorded treatment session at least once, namely giving commands, giving clues, and telling positive results. Each therapist used these principles, as emphasised in NTT. In order to stimulate children to keep trying, therapists have to give instructions. A command like ‘go’ is an instruction with a general goal, and stimulates the child to practice. Such commands were however given more often than clues (clear instructions about how to perform a task). According to the research discussed by Schmidt and Lee (1999), giving clues seems to produce better performance. NTT also emphasises that children with DCD need to experience success. The therapists accomplished this by telling the positive results of movement execution at least twice. In the videotapes observed, therapists used teaching principles differently. This might be due to differences in therapists, children or the interaction between both. The only differential information on this study’s therapists was their age, but we found no association between it and the different frequencies of the use of MTPT principles. In addition, most of the MTPT principles were not associated with the child’s M-ABC or



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TGMD-2 test scores, so the choice of principles seemed to be independent of the child’s entrance level. However, two theoretically important, non-significant correlation coefficients were found. Therapists explained the difficulty of a task more frequently to children with lower performance on the M-ABC, a test that assesses motor competence in terms of speed and accuracy. They also communicated more often what went wrong in the movement patterns and executions to children who had exhibited inferior motor patterns on the TGMD-2. This is a remarkable finding, because therapists were unaware of the scores obtained by the children on the M-ABC and TGMD-2. The finding makes clear that these two teaching principles were likely to be applied to a different extent, depending on the children’s performance levels. Further research is necessary to investigate whether the differences in teaching principles vary because of other child-related characteristics, such as behavioural ones, or to the interaction between characteristics of therapist and child. So far, the MTPT has been shown to be a reliable instrument that can be used by researchers and therapists interested in examining which teaching principles therapists actually use during NTT. It would be very interesting to investigate whether the MTPT is comprehensive enough to cover the teaching principles used in other top-down approaches, such as the cognitive orientation to daily occupational performance (CO-OP; Polatajko, Mandich, Missiuna, et al., 2001) or in treatments of children with diagnoses other than DCD.

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Cantell, M. H., Smyth, M. M., & Ahonen, T. P. (1994). Clumsiness in adolescence: Educational motor and social outcomes of motor delay detected at 5 years. Adapted Physical Activity Quarterly, 11, 115-129.

Christiansen, S. A. (2000). Persisting motor control problems in 11-12-year-old boys previously diagnosed with deficits in attention, motor control and perception (DAMP). Developmental Medicine and Child Neurology, 42, 4-7.

Fitts, P. M. (1964). Perceptual-motor skills learning. In A. W. Melton (Ed.) Categories of human learning (pp. 243-285) New York: Academic.

Geuze, R. H., & Borger, H. (1993). Children who are clumsy: Five years later. Adapted Physical Activity Quarterly, 10, 10-21.

Geuze, R. H., Jongmans, M. J., Schoemaker, M. M., & Smits-Engelsman, B. C. M. (2001). Clinical and research diagnostic criteria for developmental coordination disorder: A review and discussion. Human Movement Science, 20, 7-47.



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Hellgren, L., Jilbergt, C., Gillberg, I. C., & Enerskog, I. (1993). Children with deficits in attention, motor control and perception (DAMP) almost grown up: general health at 16 years. Developmental Medicine and Child Neurology, 35, 881-892.

Henderson, S. E., & Hall, D. (1982). Concomitants of clumsiness in young school-children. Developmental Medicine and Child Neurology, 24, 448-460.

Henderson, S. E., & Henderson, L. (2002). Toward an understanding of developmental coordination disorder. Adapted Physical Activity Quarterly, 19, 12-31.

Henderson, S.E., & Sugden, D.A. (1992). Movement Assessment Battery for Children; manual. Sidcup, Kent: The Psychological Corporation Harcourt Brace Jovanovic.

Leemrijse, C., Meijer, O. G., Vermeer, A., Lambregts, B., & Ader, HJ. (1999). Detecting individual change in children with mild to moderate motor impairment: The standard error of measurement of the Movement ABC. Clinical Rehabilitation, 13, 420-429.

Losse, A., Henderson, S. E., Elliman, D., Hall, D., Knight, E., & Jongmans, M. (1991). Clumsiness in children –do they grow out of it? A 10-year follow-up study. Developmental Medicine and Child Neurology, 33, 55-68.

Mandich, A. D., Polatajko, H. J., Macnab, J. J., & Miller, L. T. (2001). Treatment of children with developmental coordination disorder: what is the evidence? Physical and Occupational Therapy in Pediatrics, 20, 51-68.

Nunnaly, J. (1967). Psychometric theory. New York: McGraw-Hill. Polatajko, H. J., Mandich, A. D., Miller, L. T., & Macnab, J. J. (2001). Cognitive

orientation to daily occupational performance (CO-OP): Part II- The evidence. Physical and Occupational Therapy in Pediatrics, 20, 83-106.

Polatajko, H. J., Mandich, A. D., Missiuna, C., Miller, L. T., Macnab, J. J., Malloy-Miller, T., Kinsella, E.A. (2001). Cognitive orientation to daily occupational performance (CO-OP): Part III- The protocol in brief. Physical and Occupational Therapy in Pediatrics, 20, 107-123.

Reynders, K. (1992). Kinderrevalidatie in pedagogisch perspectief. [Educational perspective on child rehabilitation]. Groningen (NL), The Netherlands: Stichting Kinderstudies.

Schoemaker, M. M., Niemeijer, A .S., Reynders, K. & Smits-Engelsman, B. C. M. (in press). Evaluation of the effectiveness of a neuromotor task training for children with developmental coordination disorder. Neural Plasticity, Forthcoming.

Schmidt, R. A. & Lee, T. D. (1999). Motor control and learning: A behavioral emphasis. Champaign, IL.: Human Kinetics.

Smits-Engelsman, B. C. M. (1998). Nederlandse bewerking van de Movement Assessment Battery for Children (handleiding) [Dutch Manual]. Lisse, The Netherlands: Swets & Zeitlinger.



56

Smits-Engelsman, B. C. M., Niemeijer, A. S., & Van Galen, G. P. (2001). Fine motor deficiencies in children diagnosed as DCD based on poor grapho-motor ability. Human Movement Science, 20, 161-182.

Smits-Engelsman, B. C. M., Van Galen, G. P. & Schoemaker, M. M. (1997). Theory-based diagnosis and subclassification in developmental coordination disorder. In J. Rispens, T. van Yperen, & W. Yule (Eds.), Perspectives on the classification of specific developmental disorders (pp 229-247). Dordrecht, The Netherlands: Kluwer Academic.

Ulrich, D. A. (2000). Test of Gross Motor Development, Second Edition, examiner's manual. Austin, TX: Pro-Ed.

Van de Sande, J. P. (1999). Gedragsobservatie: Een inleiding tot systematisch observeren. [Observing behaviour: An introduction to systematic observations]. Groningen, The Netherlands: Wolters-Noordhoff.

Wallen, M., & Walker, R. (1995). Occupational therapy practice with children with perceptual motor dysfunction: Findings of a literature review and survey. Australian Occupational Therapy Journal, 42, 15-25.

8 Niemeijer -chapter 5

Chapter 5 Are teaching principles

associated with improved motor performance in

children with developmental

coordination disorder? A pilot study

Anuschka S. Niemeijer Marina M. Schoemaker


Physical Therapy 2006; 86: 1221-1230


Chapter 2

58

Abstract Background and Purpose. Therapists’ teaching skills often are disregarded in research studies. We examined whether the use of different teaching principles during neuromotor task training was associated with treatment effects. Subjects. Nineteen children (mean age=7 years 5 months, range=5–10 years) who had developmental coordination disorder and who performed below the 15th percentile on the age-related Movement Assessment Battery for Children (M-ABC) and 11 therapists participated in this study. Methods. One intervention session for each child was videotaped. The frequency of the use of principles included in the motor teaching principles taxonomy (Niemeijer et al, 2003) was correlated with changes in motor performance on the M-ABC and the second edition of the Test of Gross Motor Development. Results. Providing clues on how to perform a task, asking children about a task, and explaining why a movement should be executed in a certain way were related to better movement performance. Discussion and Conclusion. Teaching principles may be associated with success in therapeutic situations.

EFFICACY OF TEACHING PRINCIPLES


59

vidence for positive treatment effects in children with developmental coordination disorder (DCD) is becoming available as more task-oriented training programs are developed.1,2 Children with DCD, also described as clumsy

or dyspraxic, experience difficulties in acquiring adequate motor skills, such as writing or catching a ball.3 They are traditionally treated with sensory integration, process-oriented, and perceptual motor programs. Scientific evaluation studies have shown few effects of these programs on the motor performance of children with DCD.4 In more recently developed programs, which are very promising, therapists become skill teachers. They guide the child with DCD in the process of learning motor skills that children typically learn informally and perform without close attention.3 Effectiveness studies so far have disregarded the teaching skills of physical therapists, even though these might be major factors contributing to the success of treating DCD. A task-oriented treatment program that pays special attention to how therapists teach motor skills is neuromotor task training (NTT).5 Neuromotor task training is a child-centered treatment program suitable for children with DCD. It is based on recent scientific information on variables that affect motor control and motor learning.6,7 This information is incorporated into NTT to enhance motor learning in general and to enhance transfer to activities of daily life in particular. However, it is unclear whether the knowledge gathered through research in artificial laboratory experiments often with healthy children or adults, applies to motor teaching in therapeutic situations.6,8,9 This study is a first attempt to empirically associate therapeutic success with the teaching principles used by therapists who provide NTT to children with DCD. Neuromotor task training is a tailor-made program developed in the Netherlands for children with DCD.5 A therapist treating according to NTT teaches the motor tasks with which a child experiences problems. The choice of tasks depends on the individual needs of the child as well as on the expectations, capabilities, and motivation of the child and the parents. Therapists start by assessing the strengths and weaknesses of a child’s functional performance. The entrance level of training of a skill is determined by loading various aspects of the task performance. For example, in goal-directed movements, speed or accuracy in relation to distance and target size can be examined. By varying task loads during the functional assessment, the therapist can analyze which aspects of the task performance are most critical. Moreover, training of tasks with regard to these critical factors will tap the motor control processes that are thought to be involved. For instance, when a motor pattern for throwing an object is not yet developed, the child is given practice trials. To develop a throwing pattern, a variety of objects with which to practice are provided. Alternatively, if a child can catch a ball only when standing still and warned beforehand, training focuses on ball catching in complex and attention-demanding situations. Once the child has discovered a reasonably effective approach to the desired movement,10 a demand for

E


Chapter 2

60

parameterization gradually is introduced by propelling the object over various distances or by aiming the object at targets of different sizes. Toward the end of training, the therapist will examine whether the skill can be performed automatically by talking about something else or by combining it with a new task. During their training on NTT, therapists are encouraged to motivate children to learn and to provide specific instructions and feedback to the children. They can choose among different learning options, such as implicit, guided discovery or explicit learning. If explicit learning is chosen, they know that different stages of motor learning are involved: the cognitive phase, the associative phase, and the autonomous phase.11 Neuromotor task training emphasizes giving the child some sort of idea or image of the task to be learned, be it through verbal instructions or demonstrations. Schmidt and Lee reported that clear instructions about what task to perform, how to perform it, and what to attempt to achieve as a score are critical for motor learning.6 Less effective are instructions such as “go” or “OK.” Therefore, NTT therapists are trained to give instructions (clues) that provide useful and important information about the movement itself or to stress ways in which children can recognize their own errors. After a motor task is performed, providing feedback about what was done may be essential for skill learning. Therapists can talk about the outcome of a movement (results) or about the nature of the movement pattern (performance). In NTT, the provision of adequate feedback on performance is encouraged because it may enhance motor learning, especially in children with motor problems.6–8 Both the motivational and the informational functions of feedback are emphasized in NTT. Schoemaker et al2 showed that the use of NTT in the treatment of children with DCD had positive effects on handwriting and on fine and gross motor skills. Children with DCD improved their motor performance after 9 intervention sessions, whereas children in a nonintervention group did not improve spontaneously in 9 weeks. Niemeijer et al12 described the different therapeutic teaching principles that therapists actually use while treating children with DCD during 30-minute sessions of NTT. Although therapists aim to enhance motor learning by using these principles, there is no empirical clinical evidence that these mechanisms have positive effects. Niemeijer et al12 showed that the therapists’ use of principles varied but was not associated with a child’s initial level of motor performance on the Movement Assessment Battery for Children13 (M-ABC) or the second edition of the Test of Gross Motor Development14 (TGMD-2). These findings indicated that a child’s initial motor performance level does not influence a therapist’s verbal actions aimed at improving the child’s motor performance. In this pilot study, we investigated whether the frequency of use of particular teaching principles is associated with an improvement in children’s motor performance on the M-ABC and the TGMD-2.



61

Method

Sample Selection and Description Forty therapists, all registered in the Netherlands as pediatric physical therapists, were willing to participate. They learned NTT during their 3-year training and 2 extra meetings organized especially for the purpose of this study. An update on NTT was given during the first meeting. Next, the therapists recorded an intervention session on videotape while treating a child with DCD. At the second meeting, the videotapes were used to stress the NTT principles in their interventions.

Table 1. Diagnostic Criteria for Developmental Coordination Disorder (APA: Diagnostic and Statistical Manual of Mental Disorders-IV-TR; 2000; page 58). 15 Criterion Description

A Performance in daily activities that require motor coordination is substantially below that expected given the person’s chronological age and measured intelligence. This may be manifested by marked delays in achieving motor milestones (eg, walking, crawling, sitting), dropping things, “clumsiness”, poor performance in sports, or poor handwriting.




Children could be included in this study if they fulfilled the 4 criteria for DCD in the Diagnostic and Statistical Manual of Mental Disorders, 4th ed, TR (Table 1),15 if they were recently referred for physical therapy, if they had no history of physical therapy, and if their parents gave informed consent. They had to be referred for physical therapy by their general practitioner because of motor coordination problems in school or at home. This criterion indicated that their poor motor coordination interfered with activities of daily living (criterion B15). The therapists examined the children with the General Psychomotor Assessment Protocol for DCD16 to exclude obvious neurological disorders or other medical conditions that could explain the motor difficulties (criterion C15). As part of this protocol, the M-ABC was administered, and a score at or below the 15th percentile confirmed that the child’s motor coordination was substantially below that expected for his or her age (criterion A15). All children attended mainstream Dutch schools, a factor that indicates that their intelligence was within the normal range (criterion D15). Because this study investigated treatment effects through measurement


Chapter 2

62

of the progression of motor performance by independent researchers, a child also had to perform below the age-appropriate 15th percentile of the M-ABC during the researchers’ pretest assessment to be included in this study. After a recruitment period of 2 years, 19 children and 11 therapists participated in this study. The therapists were all female and between 37 and 53 years of age. The children scored below the 15th percentile on the M-ABC during the researchers’ pretest assessment. Sixteen boys (one aged 5 years, six aged 6 years, four aged 7 years, four aged 8 years, and one aged 10 years) and 3 girls (6, 8, 9 years of age) participated. Their mean age was 7 years 5 months (SD=1.3 years). None of them was diagnosed by a psychiatrist as having attention-deficit/hyperactivity disorder or a pervasive developmental disorder.

Measurement Instruments The motor teaching principles taxonomy12 (MTPT) was used to register the type and frequency of therapists’ verbal actions aimed at improving motor learning. The MTPT is a well-structured observation system developed to analyze videotaped recordings of NTT intervention sessions. The development of the MTPT was based on scientific motor learning information emphasized in NTT and on the observed (verbal) actions of therapists. The therapists’ overt actions can be clustered into 3 major categories, covering 20 different teaching principles (Table 2). These categories are mutually exclusive and exhaustive. The reliability of categories and their individual principles in the MTPT is satisfactory.12 The verbal actions of therapists are registered only once if the therapists repeat an action because the child does not react. Thus, for example, the frequency of instructions given is related directly to the child’s number of practice trials. The Cohen kappa values for test-retest reliability were between .69 and .79 for the “giving instruction” category, between .73 and .85 for the “sharing knowledge” category, and between .63 and .99 for the “providing or asking for feedback” category. For interrater reliability, they were between .60 and .77. The TGMD-2 assesses gross motor functioning with 2 subtests: locomotor and object control.14 A total of 12 gross motor skills that usually are acquired by children in preschool and early elementary grades are measured. For each skill, there are 3 to 5 performance criteria, and their observation leads to a raw score. A higher score indicates a better quality of movement patterns. The TGMD-2 provides age-related standardized scores for each subtest, with a mean of 10 (SD=3). Both standardized scores can be converted into a composite gross motor quotient (GMQ), with a mean of 100 (SD=15). The TGMD-2 possesses a high degree of reliability and little test error.14 Interscorer reliability and stability-over-time reliability coefficients varied between r=.88 and r=.98 for both the locomotor and the object control subtests and the GMQ. The SEM is 5 GMQ points for children above the age of 5 years.14 In the present pilot study, the TGMD-2 was added to the protocol because this test evaluates how a skill is



63

performed or the quality of movement patterns responsible for the performance outcome,20 rather than the product evaluated by the M-ABC.

Table 2. The motor teaching principles taxonomy, three categories with principles covering verbal actions of physiotherapists aimed at improving motor learning

Giving instructions Giving information on what to do Give commands

Draw attention and demonstrate the movement Give clues on how to execute a movement Adjust body position to make a desired action possible

Sharing knowledge Talking about movement tasks and execution (before/ during execution) Explain why it is better to execute a movement in a certain way

Revert to earlier trials Tell what the child is doing Provide rhythm or timing Explain the difficulty of a task Ask the child about the difficulty of a task Ask the child if he/she understands the task Ask the child if he/she thinks he/she can do the task (attainability) Ask the child questions about the movement execution of a task

Providing or asking Feedback

Providing comments or asking for comments after the task is completed

Tell the child what was done right during the execution Tell the child what was done wrong during the execution Tell about the results of performance neutrally Tell about the positive results of movement Tell about the negative results of movement Ask the child’s opinion about the movement execution Ask the child’s opinion about the results of the task

The M-ABC provides an indication of a child’s motor functioning in daily life.13 It was validated for the Dutch population by Smits-Engelsman.17 The M-ABC consists of 4 age-related batteries with norms. Each battery consists of 8 motor tasks that measure different aspects of motor ability; 3 items measure manual dexterity, 2 items measure ball skills, and 3 items measure static and dynamic equilibrium. A lower score represents a better performance. When a child is tested with the appropriate age range and norms, a score at or below the 15th percentile means poor performance in comparison with that of peers. The standardized scores make comparisons within a broad age range possible. The test is product oriented, as it measures motor competence


Chapter 2

64

in outcome terms (eg, speed and amount of successful attempts). This test often is used to classify DCD18 and to measure treatment effectiveness.18,19 The reliability and validity studies reported for the M-ABC are based primarily on its predecessor, the Test of Motor Impairment.13 The minimum test-retest reliability at any age was .75, and the interrater reliability was .70. The decision agreements of the total scores were 97% for age 5 years, 91% for age 7 years, and 73% for age 9 years. Thus, the test has moderate to good validity and reliability. The standard error of measurement (SEM) (test-retest) was 3.13 points; the mean total scores ranged from 13.2 to 15.4, and the standard deviations ranged from 3.9 to 7.5.19 The least detectable difference (LDD) between 2 scores thus was 8.68 (1.96×√2×SEM). Retesting within 2 weeks has shown effects of learning.19 Therefore, for monitoring of an individual child, it is recommended that measurements be obtained twice at the beginning of therapy and that the first measurement be discarded.19 Although the M-ABC is used for evaluation purposes,18,19 specific evidence of its sensitivity to change or responsiveness has not yet been published. In the present pilot study, the therapists used the M-ABC as an identification instrument for children with DCD. In addition, the researchers used it as an evaluation instrument (pretest and posttest).

Protocol Before treatment started, the researchers tested the children with the M-ABC and the TGMD-2. The raters received training to increase the reliability of test examinations. They all recorded a test session on videotape. The first author decided whether the motor assessments were in line with the guidelines for test administration as described in the manuals. The raters did not look into files to find out whether the child had been tested before or what the test scores had been. The M-ABC was administered twice before treatment, first by the therapist identifying the child with DCD and second by the researchers during the pretest assessment. Through this procedure, chances that improvement between the pretest and posttest M-ABC scores would be attributable to test-retest effects were reduced.19 After 9 weekly half-hour sessions of NTT, the researchers tested a child 1 to 2 weeks later (posttest assessment). Because physical therapists in the Netherlands can apply for payment of additional sessions after the first 9 sessions, a second posttest assessment was conducted after 18 sessions if a child received prolonged treatment. The researchers videotaped one 30-minute session of NTT for each child-therapist relationship. They made the recordings after the child had received at least 6 sessions, so as to intrude as little as possible in the treatment situation. By now, the child had become acquainted with the therapist, the room, and the material. In addition, the therapist had set goals for the intervention. The therapists did not know what purpose the videotape recordings were to serve; they knew only that the researchers wanted to know more about what was actually practiced during the sessions. The researchers who



65

had developed the MTPT analyzed the videotapes. To obtain the most consistent judgment over different videotapes, we used the MTPT frequencies from the researcher with the highest test-retest reliability (Cohen kappa values were .69–.79 for “giving instruction,” .81–.85 for “sharing knowledge,” and .66–.99 for “providing or asking for feedback”; the interrater reliability was .60–.77).

Data Analysis In this study, t tests were used for M-ABC and TGDM-2 data from all 19 children seen on 2 test occasions, and repeated-measures analyses of variance were used for data from 13 children tested 3 times (SPSS version 111,). To examine the degree to which the applied motor teaching principles (with often-skewed distributions) were associated with positive treatment effects, we analyzed the data in 2 ways: difference scores (children’s posttest minus pretest scores) were calculated, as this is the most straightforward method for measuring change,21 and these scores were nonparametrically (Spearman rank) correlated with MTPT frequencies (SPSS version 11); and the change over time was modeled between and within children.22 For this latter approach, at least 3 measurement occasions are needed; these were available for our data from 13 of 19 children. Simple multilevel regression analyses (MLwiN 1.12) were performed on all of the available data (51 measurement occasions for 19 children; the “missing” 6 occasions were not a problem) to investigate a linear effect of the MTPT variables on M-ABC or TGMD-2 over time, with the child’s age as a covariate. We standardized the regression weights: [SD(x)/SD(y)] × regression weight.23 Motor learning on the M-ABC was enhanced when a negative association was found. For the TGMD-2, however, the same was true when a positive association was found. Because of our small sample size and multiple tests for significance, the alpha level was set at .05

Results Table 3 shows the children’s mean pretest and posttest scores on the M-ABC and the TGMD-2. A statistically significant improvement between pretest and posttest scores was found. No statistical difference was found between pretest or first posttest scores for children suffered from social and attention problems. Although no differences between the compared groups were found on the CBCL symptom scales, we found a tendency for the non-referred group(s) to internalize their problems more.

1 SPSS Inc, 233 S Wacker Dr, Chicago, IL 60606. 2 Centre for multilevel modelling, University of Bristol, 35 Berkely Square, Brilstol, BS8 1JA United Kingdom.

66

8 N

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res

on th

e M

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sses

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t Bat

tery

for

Child

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(M-A

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ss M

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for t

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(n=1

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68 8 Niemeijer -chapter 5

From the initially selected groups, a comparable amount of children (ca. 25%) was excluded from children who did (n=13) or children who did not (n=6) receive additional sessions. Post hoc analyses of the group of 13 children tested 3 times showed that improvement was statistically significant between the first and second measurement occasions (M-ABC: t(12)=2.58, p=.02; TGMD-2: t(12)= –3.46, p=.05) but not between the second and third test occasions. At the individual level, we found that 7 of the 19 children showed changes that exceeded the LDD (1.96×√2×SEM) on the M-ABC and that 9 showed an improvement of 1 LDD or more on the TGMD-2. Tables 4, 5, and 6 also show the different measures of association between the categories of teaching principles within the MTPT and the children’s changes on the M-ABC and the TGMD-2. The 95% confidence intervals of the Spearman rank correlations were broad. For example, “giving clues” was associated with improvement on the TGMD-2 after 9 sessions (n=19, r=.52, 95% confidence interval: .10–.79, p=.01).

Discussion and Conclusion The aim of this pilot study was to examine whether different types of teaching principles used by therapists were associated with therapeutic effectiveness. On both motor tests, performance improved more than 1 standard deviation for the treated group as a whole, and about one third of the children showed an improvement of 1 LDD or more. The mean M-ABC score improved from a score at the 1st percentile (very poor) to a score representing the 15th percentile (boundary with normal range). The mean TGMD-2 score improved from a score at the 2nd percentile (poor) to a score representing the 10th percentile (below average). Although we detected statistically significant differences in response to treatment, we have no data to assist with the interpretation of the clinical meaningfulness of these changes. Nonetheless, 2 methods of investigating the relationship between teaching principles and changes with intervention determined that 4 principles were associated with improved performance on the TGMD-2 (giving clues, explaining why, providing rhythm, and asking about understanding) and that 2 principles were associated with improved performance on the M-ABC (adjusting body position and explaining why). Two principles associated with treatment effects were categorized as “giving instruction” in the MTPT: giving clues and adjusting body position. Therapists gave clues, that is, instructions that provided useful and important information about the motor task. Most of the instructional clues were aimed at improving the quality of motor patterns, such as “can you try to bend your knees when you jump?” This factor makes the TGMD-2 sensitive to therapeutic success by using the teaching principle of giving clues. The M-ABC assesses motor competence through the time a child needs to execute a movement or the accuracy of the child’s movements. These outcome aspects of movement execution are not necessarily improved when children have to focus on the quality of their movement performance.24 The present findings indicate that motor


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patterns improve if children receive clues about how to perform a movement. Schmidt and Lee reported that giving clues is one of the best ways to instruct a skill, as opposed to commands such as “do your best” (instructions with a general goal), because giving clues focuses an individual’s activities and serves as a reference against which achievement can be compared.6 However, Wulf and Weigelt24 showed that giving body-related instructions to adults degraded their learning of a ski simulation task compared to giving no instructions. For motor learning in adults, providing an external focus of attention, such as a cue, is thought to be beneficial in terms of both outcome of movement performance and movement patterns.25,26 Shea and Wulf26 theorized that it is probably better to perform a movement without being too concerned about the body movements, as conscious control may interfere with control processes that would otherwise regulate the movement automatically. It is unclear whether the children with DCD in this study needed clues as cues because their motor learning processes were not automatically regulated or whether they needed cues to help them focus on a specific aspect of the task instead of on all aspects at the same time (eg, internal or external, visual, or kinesthetic). Nevertheless, the present findings may confirm the idea that children with DCD need formal instruction on how to perform a task. The quality of their movement patterns was higher when they received more verbal clues about how to perform a task. Another instructional principle found to be significantly associated with improvement was adjusting body position to make a desired action possible. For example, when the child prepares for a writing task, the therapist puts the child’s arm in a “correct” position without explanation. With this action, the therapist physically guides the child. Theoretically, there are opposing views as to whether or not guidance should be effective in producing learning of the main task.6 Guidance can prevent making errors and can have positive effects on the task learned. However, it also can prevent the learner from learning from errors; therefore, transfer of learning may not be as effective when practicing with guidance as when practicing without guidance. In the present pilot study, therapists guided the children through tasks other than those assessed during the posttest assessments. Therefore, the results indicate that guidance in the form of correcting posture may have positive effects on children with DCD. Three principles in the category of “sharing knowledge” were found to be statistically significant: explaining why it is better to execute a movement in a certain way, providing rhythm or timing, and asking whether the child understands the movement task. In another promising treatment approach, the cognitive orientation to daily occupational performance (CO-OP), emphasis is placed on teaching children to plan and evaluate their own movements.3,27 Mandich et al, 28 who performed in-depth videotape analyses of CO-OP, found that many children with DCD lacked an understanding of the motor requirements of a task. They interpreted the therapists’ provision of this knowledge as a prerequisite for the use of the cognitive strategies of



70

CO-OP. Their observations and the results of the present pilot study indicate that talking (sharing knowledge) about motor tasks or movement execution with a child with DCD enhances the child’s motor performance. Although this study is a pilot study, we were able to detect some statistically significant associations. However, it is important to realize that the powers to find significant correlations with a clinically relevant medium effect size (>.30) were only .36 with 19 participants and .26 with 13 participants.29 To detect a medium effect size with a power of .80 (one-tailed alpha level set at .05), information would be needed on treatment effects and teaching principles used in 68 children. Therefore, the present results only show that children who were taught through the teaching principles identified in this study were more likely to improve their motor performance, that is, to show more treatment success, than others. Two methods were used to analyze our data. Although the use of difference scores has been debated,22 they were used in the present study because they are the most straightforward measures of change. The disadvantage of using difference scores is the unreliability of the measured scores, as these are never the true scores, and the measurement error is compounded. This unreliability makes it difficult to detect effects statistically. Another disadvantage is their relationship to initial status. As is often seen, people with the poorest performance improve the most.21 This tendency also was found in the present study, although 2 children who performed very poorly did not benefit more from treatment than others. Nevertheless, the same pattern of results was found with separate multilevel analyses used to model the change over time between and within children on each of the performance tests. Although we restricted ourselves to possibly too simple multilevel analyses, without exploiting other possibilities, such as random effects or model selection, for which we believed the data were insufficient, we were encouraged by the similarity of the results obtained by the 2 different methods. Further research with more participants is necessary to determine whether the nonsignificant findings resulted from low power. Because participation takes time that some children and parents are lacking, multiple measurement occasions are needed for more children to model the change over time in a more powerful way. Because it is of clinical importance, more insight also should be gained with regard to how the change in motor abilities influences the participation of children with DCD in, for example, activities at recess in the school yard. In addition, more research is needed to obtain information on how physical therapists use teaching principles during subsequent sessions. A limitation of the present study design is that it does not provide evidence for a causal role of teaching principles in therapeutic success. The teaching principles used in this study were not randomly assigned to the children; therefore, we cannot rule out the possibility that certain child characteristics, such as hyperactivity or introversion, influenced the tutoring style of the therapists. In future studies, we would like to assign


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children randomly to a few different therapists to determine to what extent the use of teaching principles is therapist related or results from the interaction with the child. Although this pilot study has limitations, therapists may benefit from the results, as the results may raise their awareness and provide insight on how to influence motor learning in children with DCD. Still, caution is warranted because the study is based on a small sample size (resulting in low power to find significant associations), broad age ranges, and information on therapists’ teaching principles during middle practice sessions only. The results suggest what many people already knew intuitively: children with DCD need formal instruction.

Acknowledgement The authors acknowledge the important discussions with Dr Koop Reynders, several graduate students who helped with the data collection, and Dr Marijtje van Duijn for her statistical advice. They thank the therapists who were willing to participate and have their daily professional activities registered on videotape. They also thank the children for their contributions. Finally, they thank the Dutch Health Care Insurance Board, which funded this research.

References 1.Polatajko HJ, Mandich AD, Miller LT, Macnab JJ. Cognitive orientation to daily occupational performance (CO-OP), part II: the evidence. Phys Occup Ther Pediatr. 2001;20:83–106. 2.Schoemaker MM, Niemeijer AS, Reynders K, Smits-Engelsman BCM. Effectiveness of neuromotor task training for children with developmental coordination disorder: a pilot study. Neural Plast. 2003;10:155–163. 3.Henderson SE, Henderson L. Toward an understanding of developmental coordination disorder. Adapted Physical Activity Quarterly. 2002;19:12–31. 4.Mandich AD, Polatajko HJ, Macnab JJ, Miller LT. Treatment of children with developmental coordination disorder: what is the evidence? Phys Occup Ther Pediatr. 2001;20:51–68. 5.Schoemaker MM, Smits-Engelsman BCM. Neuromotor task training: a new approach to treat children with DCD. In: Sugden D, Chambers M, eds. Children With Developmental Coordination Disorder. London, United Kingdom: Whurr; 2005:212–227. 6.Schmidt RA, Lee TD. Motor Control and Learning: a Behavioral Emphasis. Champaign, Ill: Human Kinetics; 1999. 7.Magill RA. Motor Learning: Concepts and Applications. Boston, Mass: McGraw-Hill; 1998. 8.Larin HM. Motor learning: a practical framework for paediatric physiotherapy. Physiother Theory Pract. 1998;14:33–47.



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9.Kilduski NC, Rice MS. Qualitative and quantitative knowledge of results: effects on motor learning. Am J Occup Ther. 2003;57:329–336. 10.Gentile AM. Skill acquisition: action movement and neuromotor processes. In: Carr JH, Shepherd, RB, Gordon J. et al, eds. Movement Science: Foundations for Physical Therapy in Rehabilitation. Rockville, Md: Aspen; 1987:93–154. 11.Fitts PM. Perceptual-motor skills learning. In: Melton AW, ed. Categories of Human Learning. New York, NY: Academic Press; 1964:243–285. 12.Niemeijer AS, Smits-Engelsman BCM, Reynders K, Schoemaker MM. Verbal actions of physiotherapists to enhance motor learning in children with DCD. Hum Mov Sci. 2003;22:567–581. 13.Henderson SE, Sugden DA. Movement Assessment Battery for Children. London, United Kingdom: The Psychological Corporation; 1992. 14.Ulrich DA. Test of Gross Motor Development. 2nd ed. Examiner’s Manual. Austin, Tex: Pro-Ed; 2000. 15.Diagnostic and Statistical Manual of Mental Disorders. 4th ed. text revision. Washington, DC: American Psychiatric Association; 2000. 16.Smits-Engelsman BCM, Van Galen GP, Schoemaker MM. Theory-based diagnosis and subclassification in developmental coordination disorder. In: Rispens J, van Yperen T, Yule W, eds. Perspectives on the Classification of Specific Developmental Disorders. Dordrecht, the Netherlands: Kluwer Academic; 1997:229–247. 17.Smits-Engelsman BCM. Nederlandse Bewerking van de Movement Assessment Battery for Children (Handleiding). Lisse, the Netherlands: Swets & Zeitlinger; 1998. 18.Geuze RH, Jongmans MJ, Schoemaker MM, Smits-Engelsman BCM. Clinical and research diagnostic criteria for developmental coordination disorder: a review and discussion. Hum Mov Sci. 2001;20:7–47. 19.Leemrijse C, Meijer OG, Vermeer A, et al. Detecting individual change in children with mild to moderate motor impairment: the standard error of measurement of the Movement ABC. Clin Rehabil. 1999;13:420–429. 20.Burton AW, Rodgerson RW. New perspectives on the assessment of movement skills and motor abilities. Adapted Physical Activity Quarterly2001;18:347–365. 21.Hauser-Cram P, Wyngaarden Krauss M. Measuring change in children and families. J Early Intervention. 1999;15:288–297. 22.Singer JD, Willett JB. Applied Longitudinal Data-Analysis: Modeling Change and Event Occurrence. New York, NY: Oxford University Press; 2003. 23.Snijders TAB, Bosker RJ. Multilevel analysis: an introduction to basic and advanced multilevel modeling. London, United Kingdom: Sage; 1999. 24.Wulf G, Weigelt M. Instructions about physical principles in learning a complex motor skill: to tell or not to tell. Res Q Exerc Sport. 1997;8:362–367. 25.Wulf G, McConnel N, Gärtner M, Schwarz A. Enhancing the learning of sport skills through external-focus feedback. J Mot Behav. 2002;2:171–182.


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26.Shea CH, Wulf G. Enhancing motor learning through external-focus instruction and feedback. Hum Mov Sci. 1999;18:535–571. 27.Polatajko HJ, Mandich AD, Missiuna C, et al. Cognitive orientation to daily occupational performance (CO-OP), part III: the protocol in brief. Phys Occup Ther Pediatr. 2001;20:107–123. 28.Mandich AD, Polatajko HJ, Missiuna C, Miller LT. Cognitive strategies and motor performance in children with developmental coordination disorder. Phys Occup Ther Pediatr. 2001;20:125–143. 29.Cohen J. Statistical Power Analysis for the Behavioral Sciences. Hillsdale, NJ: Lawrence Erlbaum Associates; 1988.



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9 - Niemeijer - chapter 6

Chapter 6 Fine motor deficiencies in children diagnosed as

DCD based on poor grapho‐motor ability


Anuschka S. Niemeijer Gerard P. van Galen

Human Movement Science 2001; 20: 161-182


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Abstract A sample of 125 children from grades 4 and 5 of two normal Dutch primary schools were investigated regarding the incidence of handwriting problems and other fine motor disabilities. Handwriting quality was assessed with the Concise Assessment Method for children's handwriting (BHK) and the school questionnaire for teachers (SQT). Two groups of 12 children each were formed, one group of good writers and a group of poor writers selected from the lower performance range. The latter group was investigated in depth by assessing general and fine motor ability using the Movement Assessment Battery for Children (M-ABC test) and the Motor Performance School Readiness Test (MSRT). We hypothesised that poor handwriting is part of a wider neuromotor condition characterised by faster and cruder movements, lack of inhibition of co-movements and poor co-ordination of fine motor skills. To test the theory kinematic measures of drawing movements were collected on the flower-trail-drawing item of the M-ABC test. Moreover, the experimental group of poor writers received physiotherapy during a three-month period and was tested for handwriting proficiency after therapy and again nine months later. The results revealed that 34 % of the group of 125 children displayed handwriting problems. The analysis confirmed that serious handwriting problems are accompanied by fine motor deficits. We suggest that in these children an enhanced level of neuromotor noise is compensated for by enhanced phasic stiffness of the limb system. This results in higher movement velocity and fewer velocity peaks. In the children who received physiotherapy the quality of handwriting improved.

FINE MOTOR DEFICIENCIES


77

ovement control during fine motor tasks such as writing and drawing has been studied extensively in normal children (e.g., Meulenbroek & Van Galen, 1988; Wann, Wing, & Søik, 1991). The complexities of these tasks are

nevertheless hardly understood. Research into deviant development of fine movement behaviour has not resulted in definitive insights, which is unfortunate since research on disturbed motor behaviour in children has important implications for the development of theory-based intervention programs. Studies of deviant motor behaviour are complicated by the fact that the neuromotor system works according to the principle of output optimisation. This makes it hard to distinguish whether the altered properties of a movement pattern should be attributed to some primary disorder or to the adaptation to the disorder. In the latter case the “abnormal” movement pattern that has evolved could be seen as the optimal task solution given the altered properties of the neuromotor system. In that case, it should be seen as a “normal” adaptation, considering the reduced number of available strategies or fewer degrees of freedom (Latash & Anson, 1996). The latter view is in particular true for handwriting and drawing movements. In these tasks various end-effector segments are involved which give the system a considerable amount of flexibility under changing temporal and spatial task conditions. Handwriting requires a high level of co-ordination and high-precision force regulation, which makes it a relevant task for studying the causes and effects of motor co-ordination disorders. Children with co-ordination disorders lack the normal redundancy in movement strategies. Consequently, they will be less flexible to adapt to task constraints (Smits-Engelsman, 1995). Not surprisingly, writing problems are fre-quently mentioned symptoms in children with Developmental Coordination Disorder (DCD; APA, 1994). In general, studies of dysgraphia have been conducted from a descriptive, product-oriented approach. In that tradition, the main feature of dysgraphic children is that they are not capable of producing a good quality script. Dysgraphic handwriting is said to lack consistency (Keogh & Sugden, 1985; Hamstra-Bletz, 1993) and the observed inadequacies are typically of a motor nature and not due to carelessness or ignorance, nor are poor spelling or other psycholinguistic problems the primary cause (Wann & Kardirkamanathan, 1991; Smits-Engelsman & Van Galen, 1997). Another common feature of children with dysgraphia is that they, even with the proper amount of instruction and practice in school, fail to make sufficient progress in the acquisition of the skill. In a one-year follow-up study on the persistence of deficiencies of fine motor skills and dysgraphia (Smits-Engelsman, Van Galen, & Portier, 1993, 1994) it was shown that poor writers who did not receive remedial treatment had not caught up, nor had their performance improved much in the one-year period. On the basis of these results it was concluded that poor handwriting is not caused by a developmental delay but rather by a specific neuromotor condition.

M


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When the child’s teacher has given the child additional support for some time but no progress is made and the child is found to be hampered in school by its poor grapho-motor performance, physiotherapy is often prescribed. Studies evaluating physiotherapy treatment for children with a DCD are limited in number and scope, and the results from the few studies that have been conducted are inconsistent. The findings from most efficacy studies so far are indeterminate or of little relevance to improve our insight into the possible causes of the eventual effects of a therapy programme. The reasons for this are the lack of theory-based tasks for evaluation, the heterogeneity of children diagnosed as DCD, the different (or insensitive) evaluative instruments, and the divergent treatments of children with DCD. Motor problems in children with DCD are mostly evaluated by means of product or result-oriented psychomotor tests (Geuze, Jongmans, Schoemaker, & Smits-Engelsman, 2001). Most efficacy studies have concentrated on the evaluation of motor performance per se without paying attention to the processes underlying the production of the movements. In the present study, which was inspired by a process-oriented approach, it is argued that studying the kinematics of the children’s movements may be of help to gain insight into the causes of failure to produce an acceptable movement product. In this way we expect to enhance the insight into the possible causes of the differences between good and poor performers, as well as increase our understanding of possible changes brought about by therapy. The test most commonly used to measure the effects of intervention on everyday, routine motor skills is the M-ABC test (Laszlo, Bairstow, Barttip, & Rolfe, 1989; Losse et al., 1991; Schoemaker, Hijlkema, & Kalverboer, 1994a; Schoemaker, Schellekens, & Kalverboer, 1994b; Wright & Sugden, 1995; Smits-Engelsman, Schoemaker, Van Galen, & Michels, 1996; Rintala, Pienimäki, Ahonen, Cantell, & Kooistra, 1998). Although norm-reference tests are necessary to discriminate between normal and deviant motor performance, such product-oriented ways of testing do not provide any insight into the strategies and dynamics of the way the child moves or has changed moving as a result of treatment. Another backlash of these tests is that they may not be sensitive or specific enough to measure the effects of intervention (Henderson, 1986; Schoemaker et al., 1994b). The aim of the approach used in the present study is to relate changes in motor behaviour to underlying motor control processes. A major assumption of such a research strategy is that grapho-motor tasks are the joint outcome of several cognitive and neuromotor processes. Knowing more about the processes underlying motor disorders may help to make diagnoses more articulate, and thus lead to more precise evaluations and treatment programmes. Therefore, in this study the outcomes of traditional motor performance tests are related to kinematic analyses of the writing and drawing movements in order to better scrutinise intervention effects.



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In earlier studies by Smits-Engelsman et al. (1996), DCD children with poor handwriting were compared with controls and it was found that both the quality of writing and the writing speed (the amount of letters written in 5 minutes) of the poor writers had significantly improved after physiotherapeutic treatment. In a few other studies (e.g. Schoemaker et al., 1994b; Smits-Engelsman & Van Galen, 1997) an XY tablet (digitizer) was utilised to record handwriting and/or drawing movements and analyse their kinematics. Although performance did indeed change, the authors were not able to detect which specific factors of the therapy altered motor execution in the different diagnostic and age groups or the different tasks. Different diagnostic groups (DCD with overall poor motor function versus children with fine motor problems only) seem to apply different, age-dependent strategies for the various tasks to adapt to their deficiency (for more details see Smits-Engelsman, Van Galen, & Schoemaker, 1997). A particular movement strategy that has been observed in impaired children is that of slowing down the end-effector speed, leading to a slower overall movement performance (Schoemaker et al., 1994b). Another strategy mentioned in the study is the absence of co-articulation possibly in order to avoid computationally costly joint rotations. The result is that movement trajectories are less well formed. Yet another strategy was brought forward by Van Galen, Portier, Smits-Engelsman, and Schomaker (1993) based on the theory that poor writers are characterised by increased levels of noise in the neuromotor system. The latter authors state that poor writers filter their noisy motor commands through the application of an enhanced limb stiffness regime, either by increasing movement speed (phasic stiffness), or by scaling up muscular co-contraction (tonic stiffness), exploiting friction with the writing surface through enhancement of pen pressure, or by a combination of these biophysical adaptations. The role of stiffness for effective movement control is discussed in more detail in Van Gemmert and Van Galen (1997).

Goals of the present research There are three questions that we wanted to confirm in this study. The first was after the prevalence of writing problems among Dutch school children. This has been estimated in previous studies to range from 5% to 25 % (Hamstra-Bletz, 1993; Smits-Engelsman, 1995; Mojet, 1991). The second question referred to what the underlying deficit of motor control may be. Previous findings imply that poor writers have typical kinematic profiles (low spatial accuracy, noisy velocity profiles with high energy in the tremor-related bands of the spectrum, high movement velocity), pointing in the direction of a poor muscular initiation process as the underlying deficit (Smits-Engelsman et al. 1997; Van Galen et al., 1993). The third question to be verified was the effectiveness of intervention (physiotherapy) (Schoemaker et al., 1994a,b; Smits-Engelsman et al., 1996).


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Secondly, we introduced a new set of research questions that relate to: (1) the prevalence of more general motor dysfunction, fine motor dysfunction and noisy or immature motor patterns in children with poor writing performance, (2) the effectiveness of intervention on readability and writing speed, (3) the changes in the movement kinematics of children with poor grapho-motor skills after physiotherapy.

Method

Subjects and selection procedure Parents were informed by letter of the research to be conducted in the schools of their children. All parents consented to their children participating in the first part of the study (up to the intervention). The procedure we used to determine whether a child was to be diagnosed as a good, a poor or a dysgraphic writer consisted of the administration of the concise assessment method for children's handwriting (BHK, Hamstra-Bletz, De Bie, & den Brinker, 1987), the result of which was verified by the school questionnaire for teachers (SQT, Smits-Engelsman, Van Galen, & Michels, 1995). All children attending grades 4 and 5 of two regular schools were administered the BHK (N = 125). Ninety children were in grade 4 (7-9 years) and 35 children in grade 5 (8-10 years). Ages ranged between 6.10 and 9.10, mean age was 8.4 years. The SQT was administered when a child was diagnosed as a poor or dysgraphic writer (BHK score ≥ 20; n = 41). The criterion for motor problems on the SQT was failing at least four out of six items. Target children (N=19) were those who failed both the BHK and the SQT. The parents of these children were informed about the intervention study and were asked to get a referral for physiotherapy from their general practitioner. The parents of 7 children did not think the problems were urgent enough to warrant professional help. In total, 12 children (8 boys and 4 girls, mean age 8.4) were referred for physiotherapy. These children received a more detailed examination with the M-ABC Test (Henderson & Sugden, 1992) and the Motor Performance School Readiness Test (MSRT, Huyberechts, 1981). The performance of these twelve children on the latter two tests was compared to the norm scores. From the classmates who were classified as good writers (score BHK < 19) 12 children were randomly selected as a control group (6 boys and 6 girls, mean age 8.6). The control group was formed to compare their results with those of the poor writers group on tasks for which no norms were available, i.e. the experimental flower trail drawing task.



81

Measuring instruments

The concise assessment method for childrenʹs handwriting (BHK) The concise assessment method for children's handwriting, or BHK, by Hamstra-Bletz et al. (1987) is a screening tool to recognise dysgraphia on the basis of a completed piece of handwriting. This writing task consists of copying a standard text in 5 minutes or at least the first five lines if the child is a very slow writer. The standard text gradually increases in difficulty as the text proceeds, while at the same time the size of the print decreases for each consecutive paragraph. The first five sentences have a degree of difficulty equal to a grade 3 level reading exercise (Hamstra-Bletz, 1993). The child copies the text, which it has not seen before, on unruled paper. Handwriting quality is evaluated using the dysgraphia scale of the BHK. This scale is based on the assessment of thirteen dysgraphia features, i.e. deviations from the standard handwriting model. The first two items are scored on the basis of the entire written work. Both items are measured on an ordinal scale with six categories resulting in a score from 0 to 5. For the remaining 11 items, the first five sentences are scored as to whether or not a particular feature is present in that sentence. A score of 0 is given if the feature is absent. The maximum score for a feature is 5. Each child's total score on all 13 items is then used to determine if the child is dysgraphic. Classification was done as follows: (a) not dysgraphic: a score 0-19; (b) poor writers: a score of 20-28; (c) very poor writers /dysgraphic: a score of 29 or higher. To determine copying speed the number of letters written by the child in the allotted 5 minutes, including corrections, are counted. This score is translated to a decile score scaled to the norm for the child's grade. Hamstra-Bletz (1993) defines as slow writers children with scores in the first or second decile, while those whose scores are in the eighth to tenth decile are said to be fast writers. Hamstra-Bletz reports satisfactory results regarding inter-rater reliability on the items (r = 0.71–0.89) and intra-rater reliability for grades 4 (r = 0.87–0.94) and 5 (r = 0.79–0.88). In this study the BHK is used both as a selection and an outcome evaluation instrument.

The school questionnaire for teachers (SQT) This questionnaire, developed by Smits-Engelsman et al. (1995) is based on the teacher's assessment of a child’s handwriting proficiency. The scale has 7 items that measure several different aspects of writing, such as the form of the letters, the presentation of the written work, the continuity of the hand, the exertion required for writing and the fluency of the hand. In addition, 3 items are included that ask for information on the child's spelling, general learning performance and general motor skills. The questionnaire does not provide a definition of “normal” so that each teacher has to use his or her implicit norm for what a child of a particular age ought to be able to do.


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When a child had been classified as a poor or dysgraphic writer (BHK score ≥ 20) the teachers provided their assessments of the child's abilities on each of the SQT dimensions on a five-point scale (internal consistency α = 0.93). When at least four of the items 1,2,3,5,6, and 10 are scored below average the child is regarded as definitively experiencing writing problems. Classification with the SQT is comparable to results yielded by the Groninger Motor Observation Scale (82% agreement) (Van Dellen & Kalverboer, 1990), or a general motor test (the KTK; 86% agreement) (Kiphard & Schilling, 1974).

The Movement Assessment Battery for Children (M‐ABC test) The most frequently used test of motor performance for children with motor disorders is the M-ABC test developed by Henderson and Sugden (1992) and validated for the Dutch population by Smits-Engelsman (1998). This instrument was developed to provide an indication of a child's motor functioning in everyday life. Research has shown that the M-ABC test is a useful instrument for identifying children with motor difficulties (Henderson & Hall, 1982; Laszlo & Bairstow, 1985; Sugden & Wann, 1987; Henderson. May, & Umney, 1989; Smits-Engelsman, Henderson, & Michels, 1998). The M-ABC test consists of four age-related item sets. Each set is built up of eight items that measure different aspects of motor ability; three items measure manual dexterity, two items measure ball skills and three items measure static and dynamic equilibrium. Children can score between 0 and 5 on each item, so that the total score will vary from 0 to 40. The total scores can be transformed into percentile scores that show the child's level of performance in comparison with its peers. The test has a moderate to good validity and reliability (Henderson & Hall, 1982; Lam & Henderson, 1987). Henderson and Sugden (1992) found a 62–100% agreement in classification (scores) between different raters and Smits-Engelsman (1998) 90–96% agreement of classification of motor performance between two measurements at a two-week interval. Smits-Engelsman et al. (1998) studied the relationship between the M-ABC test and the 'Körperkoordinationstest für Kinder' (Kiphard & Schilling, 1974) in 202 children. A correlation of 0.62 and a Cramer’s V of 0.56 was found for the classification of motor performance. The M-ABC test was administered to collect data on general motor performance for the poor handwriting group. The children were tested by an experienced paediatric physiotherapist.

The Motor Performance School Readiness Test (MSRT) The MSRT (Huyberechts, 1981) was originally designed as an early screening instrument for perceptual-motor deficits that may be indicative of later learning problems. The norms used are based on children aged 5–6.8 years and provided by the test manual. This test was used because of its proven sensitivity to detect fine motor



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problems in poor writers even though the items have usually already been mastered by children 6.8 years of age (Smits-Engelsman, 1995). The test consists of 19 neuro-developmental items (e.g., walking on heels, diadochokinesis, recognition and labeling of body parts, and left–right discrimination) scoring five factors; gross motor functions (static and dynamic balance), co-ordination of involuntary movements (e.g., diadochokinesis), fine motor functions and laterality, complex functions, and body scheme. The total test score and the scores on the factor co-ordination of involuntary movements and the factor co-ordination of fine motor functions are hypothesised to be the most important scores for children in this study. Involuntary associated movements are seen in young children, but they also occur in older children (> 8 years), in particular during the performance of unusual or very difficult movements. If involuntary movements are present, smoothness will be affected, although the quantitative scores may well be within the normal range (Touwen, 1979).

Flower‐trail drawing item of M‐ABC test One of the manual dexterity items of the M-ABC test (Henderson & Sugden, 1992) is the flower trail. In each age-related battery there is such an item measuring pencil control. The flower-trail item for 7- and 8-year-old children (Fig. 1) was used in this study for the recording of the children’s movement dynamics. The children were instructed to draw a line between the two solid lines of the flower trail as accurately as possible. They were also told not to lift the pen while drawing the trace. There was no speed instruction or time constraint. The child was allowed to draw the line in either the clock-wise or anti-clock-wise direction. Prior to the experiment each child was allowed to practice so that it could familiarize itself with the experimental setting, which also allowed the experimenter to check that the child understood the task. The flower-trail tasks were printed on normal sheets of A4 paper, three test figures per page. All children had to complete 10 flower trails. They were seated at a table on which the digitizer was placed. For every series of three test figures a fresh sheet with three flower trails was laid upon the digitizer. Subjects wrote with a wireless electronic pen of normal appearance and weight. Pen position data over time were recorded using a Wacom UD-1218-RE digitizer with a wireless inking pen and the OASIS software (De Jong et al., 1996). The position of the pen tip, and the force exerted along the axis of the pen, was recorded with a sampling frequency of 206 Hz. All data were stored for later analysis using the same software package. OASIS was especially designed for psychological tests and experiments that employ a digitizer. Before each experiment a calibration of the pen pressure on the digitizer was performed at 0.25 N intervals. In the analysis, the start and end (vertical) parts of the flower trial were not taken into account. For each dependent variable the mean and the standard deviation of ten repeated flowers was taken for


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further analysis. The following kinematic variables were used as dependent variables: Trajectory Length in cm: distance in centimetres covered by the pen tip; Movement Time in seconds: total time in seconds taken to complete the flower; Velocity in cm/seconds: average of absolute velocity of the pen tip; Number of Velocity Peaks: number of times absolute velocity reached a peak; Pen-up Time: time during which the pen was not on the digitizer; Number of Lifts: number of times the pen was not on the digitizer; Pen Pressure in N: average axial pen pressure in Newtons.

Intervention Two paediatric physiotherapists treated the children 18 times over a period of approximately 3 months. The child-specific therapy was based on the individual assessment results. The actual writing of letters or words was not trained. The therapy approach was build on the following three elements: 1. Prewriting exercises, aimed at learning to adapt force to different contexts and with different materials (Smits-Engelsman & Van Tuyl, 1998). Starting point for these exercises is that children experience fluent movements during trajectory formation. From there on movements with different amplitudes are trained (force generation) until

Figure 1a: the flower trail, one of the manual dexterity items of the Movement ABC (Henderson and Sugden, 1992). Figure 1b: the flower trail as recorded on the XY-digitizer with Oasis software (De Jong et al., 1996).



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a certain level of constancy is obtained. After that, exercises to train spatial and temporal constraints are brought into the program. 2. Fine motor training if manipulative skills were found to be insufficient to perform prewriting exercises. 3. "Gross" motor function training only if one or more of the prerequisites for sitting and independent arm movements were lacking (See 2).

Procedure The drawing task was administered individually in a quiet room. The total time needed for the motor performance measurements of the children with writing problems was about 2 hours and the drawing task took about 30 minutes. The poor writers were re-assessed twice after the physiotherapy intervention, approximately 3 and 12 months after the first measurement.

Data analysis To test differences in general or more specific aspects of motor proficiency between the experimental group and the control children we analysed the results on the motor assessment scales, the school performance data, and the kinematic data of the flower trail. For the contrast analyses on BHK data t-tests (corrected for equality of means) were used. The kinematic variables used were mostly skewed, so comparisons were made with non-parametric tests for significance, the Mann–Whitney U test for differences between groups and the Wilcoxon test for changes over the three-month period. Because of the small number of subjects, we could have used a less conservative significance level, but to correct for multiple comparisons, the probability level was set at 0.025 to establish significant effects. Since group data obscure individual differences between subjects, we will report how many children in the experimental group really deviated from the norm values.

Results

Prevalence of writing problems in the pre‐selection group (N = 125) On the basis of the concise assessment method for children's handwriting (BHK, Hamstra-Bletz et al., 1987) children were classified as good, poor or dysgraphic writers. Scores ranged from 5 to 41, mean score was 17 and were normally distributed. This procedure resulted in identifying 84 good writers (67%), 34 poor writers (27%) and 7 dysgraphic writers (6%). Nineteen children (15%) failed on both the BHK and the SQT, which indicates they were not only characterised by substantially lower writing performance levels given their chronological age, but that their teachers had also reported interference with daily school activities.


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Comparison between the academic performance of the poor writers and the normative data Because handwriting proficiency was the basis for assigning children to either the group of good or (very) poor writers, it is not surprising that a significant difference was obtained on the handwriting quality score of the BHK, as well as on all handwriting items of the SQT. The spelling performance of the children with poor handwriting, however, fell within the normal range. No significant differences were found for copying speed. Table 1 presents an overview of the performance of the poor writing group and the control group on the BHK and SQT.

Table 1. Performance of the poor writers and the good writers (control group); Means and S.D. on the BHK and SQT Poor writers

(n = 12) Good writers (n = 12)

p-value

BHK handwriting quality 25 (6) 12 (6) 0.0001

BHK copying speed 132 (35) 138 (23) n.s.

Teachers' rating for writing 5.1 (0.64) 6.2 (0.49) 0.002

Total score SQT 38 (4.7) 26 (6.7) 0.001

Writing items SQT 20 (3.7) 12 (3.8) 0.001

Prevalence of overall motor dysfunction, fine motor dysfunction, and noisy or immature motor patterns in the group of poor writers Of the 12 children selected for a more detailed examination of overall motor function, three scored below the 15th percentile on the M-ABC test. Seven children scored below the 15th percentile on the manual dexterity scale of this test. Compared to the norm scores of the MSRT for 6.8-year-old children, the scores of three poor writers were still deviant (below the 30th percentile) on the total MSRT. On the factor fine motor skills 10 children were found to have deviant scores and on the factor co-ordination of involuntarily movements seven children (see Table 2 for their individual scores).



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Table 2. Description of the poor writers’ gender, age and their individual scores on the BHK, M-ABC, M-ABC manual dexterity, the MSRT-raw total, 2nd, and 4th factor scores with decile scores (2nd factor is fine motor skills and laterality and the 4th factor is coordination of involuntary movements)a Gender Age BHK-

score M-ABC

M-ABC- manual

MSRT MSRT Factor 2

MSRT Factor 4

M 7,8 27 * 5.5 0 54 – 9 10 – 3 * 5 – 9 F 7,9 22 * 9 4* 55 – 9 12 – 6 5 – 9 F 7,7 28 * 6 2 52 – 8 9 – 1 * 3 – 3 * M 8,2 20 * 5 4 * 59 – 9 11 – 4 4 – 7 M 8,6 23 * 7.5 4 * 45 – 6 9 – 1 * 1 – 1 * F 8,0 31 * 5 2 45 – 4 8 – 1 * 0 – 1 * M 9,0 27 * 21 * 10.5 * 38 – 3 * 8 – 1 * 1 – 1 * M 7,8 23 * 9 7 * 39 – 3 * 8 – 1 * 1 – 1 * M 9,3 20 * 12.5 * 10 * 48 – 8 10 – 2 * 5 – 9 M 8,4 23 * 5 3.5 38 – 3 * 7 – 1 * 1 – 1 * M 8,0 41 * 0 0 53 – 9 10 – 3 * 3 – 4 F 9,10 22 * 10 * 8.5 * 50 – 7 9 – 1 * 3 – 3* 4M:1F 8,4 25 8 4.6 48 9.3 2.7 a An asterisk (*) means deviant

Differences in the errors and kinematic profiles in the flower trail of poor and proficient writers The mean number of drawing errors (crossings of the outlines of the flower-trail figure) was 17 for the poor writers and 5.5 for the control group (Z = –2.98, p <0. 01). No significant difference in average trajectory length of the 10 flowers was found between the two groups. However, for movement time (time needed to complete a figure) and movement velocity while drawing, main effects for groups were found. The poor writers finished the tasks in less time (p < 0.025) and they also used a higher (p < 0.025) movement velocity. There was a non-significant tendency for good writers to spend, on average, more time pausing above the paper (0.56 seconds versus 0.39 seconds for the poor writers). In guiding the pen through the flowers the poor writers' movements tended to have fewer velocity peaks. No differences were found for pen pressure, nor for the number of times the pen was lifted. Table 3 presents the means, standard deviations, test-statistics and p-values for each group.


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Table 3. Kinematic data on the flower-trail drawing item and comparison of the experimental group of poor writers (n=12) and the control group of good writers (n=12) using the Mann–Whitney U test Experimental

group Control group Z-value p-value

Trajectory length (cm) 35.1 (3.2) 36.3 (4.8) -1.44 .16 Movement time (seconds) 28.3 (6.9) 36.1 (7.3) -2.25 .024 Movement velocity while drawing (cm/second)

1.66 (0.32) 1.36 (0.16) -2.48 .012

Number of velocity peaks 176.1 (39) 214 (49) -1.73 .083 Pen-up time (seconds) 0.39 (0.28) 0.56 (0.24) -1.85 .065 Number of lifts 1.38 (1.2) 2.14 (2.5) -1.33 .20 Pen pressure (N) 2.25 (0.94) 2.26 (0.76) -.81 .44

Writing performance of the poor writers before and after treatment At the time the children were assessed as having writing problems according to the concise assessment method for children's handwriting (BHK) their writing quality score was 25. After the three-month treatment period their mean score for quality had improved to 21 (t(12) = 1.93, p < 0.05). At the third measurement, 12 months after the first, they wrote qualitatively better still, resulting in an average score of 14, which is a significant improvement of the writing product (t(12) = 5.2, p < 0.001). As to writing speed, before treatment they wrote on average 132 letters in 5 minutes, whereas after the treatment period they wrote 149 letters (t(12) = 1.4, p = 0.09, n.s.). At the third measurement they wrote 212 letters in 5 minutes, i.e., 80 letters more than before therapy (t(12) = 4.27, p < 0.001). Table 4 gives insight into the individual improvement over the 12 months period corrected for normal development. Changes in the kinematic profiles of the poor writers after 3 months The mean number of drawing errors did not decrease between the two measurements. However, a significant difference in the trajectory length measure was found (Z = –2.12, p < 0.05). At the second measurement (see Table 5) the trajectory covered was almost 2 cm shorter per flower trail (35.1 vs. 33.3 cm, respectively). For movement time, movement velocity while drawing, and number of velocity peaks no significant main effects were found. During the second measurement the poor writers completed the tasks within the same time as during the first measurement and used the same movement velocity. However, when corrected for trajectory length, the poor writers tended to use fewer velocity peaks per distance at the second measurement (Z =–1.96, p = 0.05). There was also a tendency to spend on average shorter intervals above the paper



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(39 and 18 seconds per flower; Z = –2.09, p < 0.05) and to lift the pen less often (1.38 vs. 0.54 times per flower; Z = –1.96, p = 0.05). No differences were found for pen pressure.

Table 4. Classification of the individuals (in the experimental group of poor writers) before and after treatment and one year after starting treatment on handwriting quality and copying speed using the concise assessment method for children's handwriting (BHK; Hamstra-Bletz, et al., 1987) Handwriting quality Copying-speed Dysgraphic Poor Good Slow Normal Fast Dysgraphic writers

Before treatment 2 2 After treatment 2 1 1 After 1 year 2 1 1 Poor writers Before treatment 10 1 7 2 After treatment 1 5 4 1 7 2 After 1 year 2 7 1 5 3

Table 5. Kinematic data on the flower-trail drawing item of the experimental group of poor writers (n=12) before and after treatment with physiotherapy (Wilcoxon test) Before

treatment After treatment

Z-value p-value

Trajectory length (cm) 35.1 (3.2) 33.3 (0.7) -2.12 0.03 Movement time (seconds) 28.3 (6.9) 24.8 (4.0) -1.34 0.18 Movement velocity while drawing (cm/s)

1.66 (0.32) 1.75 (0.25) -0.78 0.47

Mean number of velocity peaks

176.1 (39.0) 143.0 (24.8) -1.96 0.05

Mean pen-up time (seconds) 0.39 (0.28) 0.18 (0.15) -1.96 0.05 Number of lifts 1.38 (1.20) 0.54 (0.38) -2.09 0.04 Pen pressure (N) 2.25 (0.94) 2.20 (0.68) -0.31 0.75

Discussion One of the aims of this study was to provide prevalence data on handwriting difficulties in a normal population of grade 4 and grade 5 children. These findings confirm once again that handwriting is a difficult skill to accomplish. One-third of the children in the sample fell short of the norms for handwriting quality of the BHK. For about 15% of the


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children, both the objective BHK and subjective measures (SQT filled out by the teachers) verified writing difficulties. The M-ABC test, an instrument for overall motor performance, provides an indication of a child's motor functioning in everyday life. Although only 3 (out of 12) children showed a below-norm total score on the M-ABC test, the children in the evaluation study meet the diagnostic criteria for DCD described in DSM-IV (APA, 1994). All selected children experienced writing difficulties according to their teachers and as measured by an objective handwriting assessment tool (BHK). Moreover, their inadequate development of a specific academic motor skill (handwriting) evidently interfered with daily school activities. Parents acknowledged the problems and general practitioners were willing to refer the children to physiotherapy. To our knowledge, the symptoms of the children were not caused by a known physical disorder like neurological or sensory deficits or mental retardation. In addition, the M-ABC test indicated that seven of the twelve children were having problems with fine motor skills. The MSRT gave a similar picture. According to the results on the MSRT only 3 children seemed to function below the level of a normal total score. One should keep in mind, however, that the norm scores of this test apply to children between the ages of 5–6.8. Beyond this age a ceiling effect is expected because the test is designed to assess if children perform at elementary school entrance level, e.g., have adequate fine motor skills (factor 2). Likewise, an improvement is expected on factor 4, involuntary movements, because dyskinetic movements are supposed to disappear in older age groups. All but one of the 12 poor writers, however, were performing below par on factor 2, measuring co-ordination of fine motor skills and half of the children was not able to suppress mouth-hand automatism's (part of factor 4). It can therefore be stated that the group of poor writers is characterised by substantially lower performance in fine motor co-ordination given their chronological age. If one wishes to identify fine-motor co-ordination problems in children with handwriting difficulties by means of a general norm-referenced motor test, we recommend that both motor performance tests used in this study be administered (manual dexterity items of the M-ABC test and at least the items representing factor 2 of the MSRT). When comparing the performance of the poor writers (children with DCD, mainly characterised by poor fine motor performance) to published norms and the matched controls, it became clear that they are most typically characterised by spatially inconsistent motor behaviour and by fine motor deficits. A persistent feature is a high degree of involuntary movements (dyskinesia). On the basis of the kinematic analysis of the children’s drawing movements we also found that poor writers can be characterised as being less capable to adapt to spatial demands. At the same time, they exhibit faster movements, fewer velocity peaks and fewer pauses above paper. Taken together, this may imply that they prefer a more ballistic movement strategy that is less dependent



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upon visual correction. From the perspective of the neuromotor noise hypothesis as discussed in the introduction of this paper this may mean that the present group of poor writers chooses to apply higher phasic stiffness to filter a higher level of neuromotor noise in their neuromotor apparatus. In Van Galen et al. (1993) and Smits-Engelsman and Van Galen (1997) direct evidence for higher tremor-related energy in the movement velocity spectra of poor writers was found. This makes them particularly deficient in making fine adaptations to the high level of accuracy required in the experimental task used in this study and less vulnerable in the free writing task on an unruled paper (BHK). These observations are in accordance with our theory published earlier that the deficit in this group of children is caused by a problem in the recruitment of muscle force or muscular initiation stage (Smits-Engelsman & Van Galen, 1997; Van Galen et al., 1993). We have to consider, however, which other underlying processes might cause the fine motor disorder in this group of DCD children. Wilson and McKenzie (1998) conducted a meta-analysis to identify information-processing factors that characterise children with DCD. According to these authors relevant main factors are Visual Processing, Other Perceptual Processing, Motor Control, General Intelligence and Motor Skill. The present study does not support the idea that general intelligence and general motor skill are highly relevant factors. Spelling and general learning performance were in the normal range and only 3 children failed on overall motor performance (the M-ABC test). Children with DCD, however, are known to display deficits in the use of visual feedback (Geuze & Kalverboer, 1987; Lord & Hulme, 1987; Van der Meulen, Denier-van de Gon, Gielen, Gooskens, & Willemse, 1991; Wilson & McKenzie, 1998). For accuracy, visual monitoring of movement is necessary to detect errors and correct movements. Because the flower-trail is performed with full vision, kinaesthetic information may be redundant (Laszlo & Baker, 1972) and kinaesthesia is not the first deficit to be considered. During the practice trials in our experiment the children had no difficulty in pointing out the mistakes they made, they were perfectly aware that they had crossed the lines. However, we cannot conclude that visual information processing is not a factor to be considered in causing the poor motor outcome because it was not manipulated as an experimental factor in the present research. In accordance with an earlier study by Smits-Engelsman et al. (1996) it was found that the children wrote more accurately after 3 months of physiotherapeutic treatment. Also, this improvement was still present after 9 months. One year after the first measurement, the children -their increased age levels taken into account- still wrote more letters in 5 minutes and the readability of their handwriting product had further improved. As the writing of 9 of the 12 children now was of normal quality and produced at normal speed, this change could not be attributed to a changed speed-accuracy trade-off. Immediately after treatment the poor writers produced higher


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quality handwriting. After some practice the children were indeed able to increase their copying speed without any negative effect on the quality of their writing performance. In the introduction we stated that a process-oriented analysis might give insight into the changes in movement strategies. During the second measurement the less proficient writers used less time to complete the task, lifted their pens less often and for shorter periods, covered more centimetres per second, and displayed fewer velocity peaks. We already mentioned the possibility that this movement strategy may be an expression of applying higher phasic stiffness to filter out tremor. The pen pressure applied did not differ from that of the controls nor changed over time. This means that poor writers do not increase the tonic stiffness of the writing hand. Although increased pen pressure is often seen in tasks with high mental or physical stressors (Van Gemmert & Van Galen, 1997) this is not the strategy used by the present group of poor writers. The reason may simply be that children in the age groups under study already use relatively high pen pressure (Mojet, 1991). Still higher pen pressure would ask for enhanced muscular forces to drive the hand-pencil system. Higher forces, however, are typically accompanied by higher neuromotor noise and thus the strategy would not help in counteracting excessive levels of neuromotor noise. The results of our study indicate that the poor writers contrast most clearly and selectively with the better performers in that they fail to accommodate for the spatial accuracy constraints of the experimental tasks. Three months later, after physiotherapy, the differences between the movement profiles of the children with poor handwriting and those of the controls displayed during the execution of fine motor tasks seemed to have become more pronounced. Contrary to what one might expect, the movement strategy used by the poor writers deviated more from the controls than 3 months earlier. However, they did become better in using their typical movement strategy of higher phasic stiffness, apparently in order to find an optimal task solution given their noisy neuromotor system.

Acknowledgements We wish to thank all the children, their parents and teachers for their commitment and willingness to participate in this study, and Mrs Marjo Stevens and Mrs Ingrid Vrenken for the physiotherapy sessions with the children.

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Smits-Engelsman, B.C.M., Van Galen, G.P., & Michels, C.G.J. (1995). De leerkracht beoordeeld: Inschatting van schrijfvaardigheidsproblemen en motorische achterstand bij basisschoolleerlingen [Teachers’ assessment of the motor proficiency level and motor writing skills of elementary school pupils]. Tijdschrift voor Onderwijsresearch, 20, 285-299.

Smits-Engelsman, B.C.M., Van Galen, G.P., & Portier, S.J. (1993). Cross-sectional and longitudinal study on developmental features of psychomotor aspects of handwriting. In Proceedings of the sixth handwriting conference of the international graphonomics society: motor control of handwriting. Telecom, Paris.

Smits-Engelsman, B.C.M., Van Galen, G.P., & Portier, S.J. (1994). Psychomotor Development of Handwriting Proficiency: A cross-sectional and longitudinal study on developmental features of handwriting'. In C. Faure, P. Keuss, G. Lorette, & A.Vinter (Eds.), Advances in handwriting and drawing: A multidisciplinary approach. Europia, Paris.

Smits Engelsman, B.C.M., Van Galen, G.P., & Schoemaker, M.M. (1997). Theory-based diagnosis and subclassification in developmental coodination disorder. In J. Rispens, T. van Yperen and W. Yule (Eds.), Perspectives on the classification of specific developmental disorders. Dordrecht: Kluwer Academic Publishers.

Smits-Engelsman, B.C.M., Schoemaker, M.M., Van Galen, G.P., & Michels,C.G.J. (1996). Physiotherapy for Children’s Writing Problems. In M.L. Simner, C.G. Leedham, & A.J.W.M. Thomassen (Eds.), Handwriting and drawing research: Basic and applied issues. Amsterdam: IOS.

Sugden, D.A., & Wann, S. (1987). The assessment of motor impairment in children with moderate learning difficulties. British Journal of Educational Psychology, 57, 225-236.

Touwen, B.C.L. (1979). Examination of the child with minor neurological dysfunction (2nd ed.). Clinics in Developmental Medicine, vol. 71. London: SIMP/ Heineman.

Van Dellen, T., & Kalverboer, A. F. (1990). Groninger Motorische Observatielijst. [Groningen Motor Observation Scale]. Laboratory for experimental psychology, Groningen State University.

Van der Meulen, J.H., Denier-van de Gon, J.J., Gielen, C.C., Gooskens, R.H., & Willemse, J. (1991). Visuomotor performance of normal and clumsy children II: Arm-tracking with and without visual feedback. Developmental Medicine and Child Neurology, 33, 118-129.

Van Galen, G.P., Portier, S.J., Smits-Engelsman, B.C.M., & Schomaker, L.R.B. (1993). Neuromotor noise and deviant movement strategies as an explanatory ground for poor handwriting in children. Acta Psychologica, 82, 161-178.

Van Gemmert, A.W.A. , & Van Galen, G.P. (1997). Stress, neuromotor noise and human performance: A theoretical perspective. Journal of Experimental Psychology: Human Perception and Performance, 23, 1299-1313.


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Wann, J., Wing, A.M., & Søvik, N. (1991). Development of graphic skills. London: Academic Press.

Wann, J., Kardirkamanathan, M. (1991). Variability in children's handwriting: Computer diagnosis of writing difficulties. In: J. Wann, A.M. Wing, & N. Søvik (Eds.), Development of graphic skills. London: Academic Press.

Wilson, P.H., & McKenzie, B.E. (1998). Information processing deficits associated with developmental coordination disorder: A Meta-analysis of research findings. Journal of Child Psychology and Psychiatry, 39, 829-840.

Wright, H.C., & Sugden, D.A. (1995). Management of children aged 6-9 years with developmental coordination disorder. In I. Morisbak, & P.E. Jorgensen (Eds.), 10th Symposium Conference Proceedings, ISAPA, ’95: Quality of life through adapted physical activity and sport.

10 - Niemeijer - Chapter 7

Chapter 7 General discussion



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he main objective of this thesis was to study whether Neuromotor Task Training (NTT), a new paediatric physiotherapy programme which was developed especially for children with developmental coordination disorder, is effective.

We presented two studies that show effects of NTT on movement task performance (speed and accuracy), movement patterns, and the motor processes underlying task performance (chapters 3 and 6). The main finding of our controlled trial was a remarkable improvement in about half of the children after nine weekly 30-minute sessions of NTT, whereas hardly any positive change was observed in children with DCD during a three months period of no intervention. The changes in the treated group were even more apparent after 18 sessions of NTT. Children especially improved on motor tasks comparable to those that were trained during NTT sessions. In addition, we found that therapy was successful regardless the children’s behavioural symptoms. Furthermore, according to the guidelines of NTT, the therapists were using several teaching principles to enhance learning. The principles ‘providing clues on how to perform a task’, ‘asking children about a task’, and ‘explaining why a movement should be executed in a certain way’ were associated with improvement of motor performance. We also found in children recruited because of poor grapho-motor ability that their writing speed and accuracy improved after NTT sessions. In addition, we found a change in the underlying writing process indicating that children with poor handwriting had learned to use their typical movement strategy in a more effective way.

Strengths of the presented studies There are several strengths of the studies conducted to investigate whether NTT was effective. First, we used a control group to evaluate NTT in children with DCD (chapter 3). A control group has frequently been lacking in studies evaluating treatment programmes (Schoemaker et al., 1994; Wright & Sugden, 1998, Martini & Polatajko 1998). If a control group has been used, it was often made up by typical developing children (Schoemaker, 1992). In the present controlled trial, we compared the developmental progress in treated children with the progress rate of their non-treated DCD peers. The use of a non-treatment control group revealed that the performance of untreated children with DCD remained the same or even deteriorated within a three months period. Therefore, the progress seen in the children who received NTT could be attributed to the treatment. Second, the treatment programme provided to the children with DCD was especially designed for them and incorporated recent knowledge about motor control and motor learning. So far, therapists had eclectically used what they had learned on several courses. Such combined approaches have demonstrated smaller effects than pure approaches (Kavale & Mattson, 1983; Mandich et al., 2001). Thus, the fact the NTT was especially developed for children with DCD might explain finding positive effects, up to 1 standard deviation, on general motor tests. Third, the weekly

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treatment sessions of NTT in the controlled trial were provided in a naturalistic unrestricted way, taking illnesses and holidays into account/ as they came. The lack of artificial constraints in our study makes that the results can be generalized to how treatment is provided in real life. Fourth, the external validity of our studies is high, because multiple therapists treated the children, which makes it possible to generalize the positive effects found to other Dutch paediatric physiotherapists treating with NTT. Moreover, we did not tell therapists what skills to teach or how to teach a skill to an individual child (no fixed treatment recipes), which makes it more likely that therapists not involved in the present studies are able to provide the same effective service. Fifth, we not only evaluated NTT in terms of outcome of movement (speed and accuracy), but also in the quality of the children’s movement patterns. Moreover, in chapter 6, we evaluated changes in the processes that underlie motor performance. Our results showed that the outcome and quality of motor performance had changed during the period in which children were treated with NTT, but also the processes underlying motor performance. Sixth, in contrast to most effectiveness studies, we not only concentrated on the evaluation of motor performance per se, but also paid attention to what happened during the sessions. We took a look in the ‘black box’ called therapy. We made video recordings of NTT treatment sessions, and the therapists wrote treatment reports. This information allowed us to examine whether the treatment was provided according to NTT guidelines. In addition, we used the information about the content of the therapy sessions to get more insight in the efficacy of several elements in Neuromotor Task Training.

Limitations of the studies Besides the strengths of the studies presented in this thesis, there were also some limitations. First, one might argue that the positive results are not providing real hard evidence that NTT works because the children in the controlled trial were not randomly assigned to the treatment or non-treatment control group. The groups of children were not randomly selected because parents were unwilling to participate if their child had a chance of being put on a fictive waiting list. Moreover, because paediatric physiotherapists (PPTs) regarded their services as effective, they felt it was unethical to withhold treatment when a child was referred to them. In addition, Eccles stated that randomized controlled trials (RCTs) should only be considered when there is genuine uncertainty about the effectiveness of an intervention (Eccles et al., 2003). The disadvantages of RCTs are the tight inclusion criteria and the artificial constraints placed upon participants which limits the generalizability of the findings (Eccles, 2006). For our controlled trial (chapter 3), we attempted to identify a control group of similar characteristics and performance to the study population and collected data in both groups before and after a period in which NTT or no intervention was applied to them. We formulated criteria for the participation of children to include groups as



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homogeneous as possible because heterogeneity may obscure the effects reached in subgroups of children (Schoemaker et al., 1994). In previous analyses, not published in this thesis, we found that both recruited groups did not differ in mean age, medical background, average birth weight, age at which motor milestones were reached, living environment, or highest educational level of the mother/father (Niemeijer et al., 2003). Their motor problems were equally severe according to the M-ABC test, but the nature of the difficulties differed (chapter 2). Thus, as in most studies, even in apparently well matched control and study groups (Eccles et al., 2003), performance at pretest differed. This pretest imbalance suggests that the control group was not truly comparable, and might not experience the same developmental progress as the treated group, if the latter was not treated. The control group had relatively more difficulties with manual dexterity. In chapter 3, we found that half of the children in the treatment group was (also) treated for fine motor skills/ handwriting, and a third of these children showed significant progress on the M-ABC manual dexterity items after NTT. Furthermore, in a group of children recruited because of poor grapho-motor skills we found effects of NTT in writing behaviour (Smits-Engelsman et al., 1996, Niemeijer et al., 2000; Schoemaker et al., 2003) and in the underlying motor processes (chapter 6). Thus, although the treatment and non-treatment control groups differed in their health care needs, we have no reason to assume that their spontaneous developmental progress rate would have been different. Therefore, we may conclude that the improvement was most probably caused by NTT. A second limitation might be the use of several assessment instruments to test children before and after a (non-)intervention period. Multiple testing for significance raises the chance to find one or more (sub)tests to show a statistically significant improvement. Our within treated-group analyses, however, showed that children improved most on tasks similar to those trained during NTT. It is hard to believe that this result is a due to chance, because it confirms the mainly task-oriented bases of NTT. Moreover, in an earlier study evaluating physiotherapy in children with writing difficulties, we also found a relationship between the tasks trained and the effects measured (Niemeijer et al., 2000). Although the number of children was sufficient to prove that NTT is effective, our sample sizes were too small for several additional analyses such as interaction effects between therapists and children. We trained 40 therapists, but only 17 of them recruited children for this study. In contrast to what we had hoped for, only 40 children recently referred for physiotherapy were participating. No effect of therapist on the treatment results was found, which might be caused by the small number of children per therapist. In addition to the positive effects of NTT, we were able to show the impact of some behavioural characteristics of the children (chapter 3), and of some teaching principles (chapter 5) on the successfulness of treatment. Nevertheless, not all suspected intervening mechanisms were found to attribute to NTT’s effectiveness. For

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example, ‘demonstrating a skill’ enhances motor learning in typical developing children and adults (Schmidt & Lee, 1996). Although ‘demonstrating a skill’ is one of the guidelines of NTT, it was not much applied by the physiotherapists and showed no association with the therapeutic benefits. This latter finding might be due to a lack of power (too small sample sizes), but it also seems to correspond to recent experimental findings in children with DCD. Children with DCD often perform visual perceptual and visual-motor integration tasks poorly in comparison to control children (Van Waelvelde et al., 2004) They frequently have problems identifying common objects from incomplete visual presentations (Sigmudsson & Hopkins, 2005) Moreover, they experience problems with several activities that they see their parents, peers, or significant others perform daily, so they had enough models to learn from already. It might thus well be, that we did not find significant associations because these simply do not exist. More research is necessary as this information is very relevant for the therapist treating the children.

Conclusion The child-centered and mainly task-oriented NTT methodology is effective. In contrast to other effectiveness studies, we were able to show that the effects are not (solely) due to general effects such as Hawthorne effects (the attention paid to the children) or spontaneous development. We found very specific effects of NTT: children improved most on tasks comparable to those trained. Because NTT was especially developed for children with DCD and turned out to be an effective treatment approach, we plead that other therapists will also start treating such children according to NTT guidelines.

Future research Although, we were able to show that NTT for children with DCD is more effective than no treatment during a 3-month period, more research is necessary. We do for example not know what the long term effects of NTT are. Neither do we know whether NTT is a better methodology to treat children with DCD compared to other treatment methodologies, such as motor remedial teaching (MRT) or the CO-OP approach which was recently developed in Canada. In future research, we would not only like to investigate which approach is most effective in general, but also which approach is most effective for different (sub)groups of children with DCD. Insight in why some children improve more than others is necessary to improve our knowledge on motor learning and development. This insight might have clinical implications as well. Although we found no indication that certain tasks were more easily improved, we think that more research is needed into the responsiveness of motor tasks to change. In addition, although the impact was low, we found indications that the behaviour of children is influencing the extent to which NTT was effective. Children who were more withdrawn, or had more physical complaints statistically



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improved their quality of motor performance less than their DCD-peers. Whereas those children that were more anxious/depressed improved more. It is unclear why these correlations were found and more research into the impact of these associations in daily life is worthwhile. Our results might be attributed to the small sample size which makes that exceptions have a large impact on the data and their interpretation. On the other hand, the three symptoms which are all considered as internalizing behaviour might have different origins making a child more or less responsive to treatment. It might be that the co-occurring anxiousness or depression are caused by the motor problems as a consequence of their inability to succeed in motor tasks. Whereas the other behavioural symptoms, withdrawn and physical complaints, could be co-morbid conditions of the motor problems. More research is necessary as this hypothesised difference might lead to other long term outcomes of treatment as well. In future research, we recommend not only to follow-up on the children’s motor behaviour, but their socio-emotional development as well. A follow up of the children participating in our controlled trial, with motor tests and the CBCL, may provide insight in the long term development of children’s health care needs. In the present controlled trial, we were able to videotape one treatment session per child. More research is needed to obtain information on how physical therapists use teaching principles during subsequent sessions. It might be that physiotherapists each have their own tutoring style. Therefore, in future studies, we would like to assign children randomly to a few different therapists to determine to what extent the use of teaching principles is therapist related or results from the interaction with the child. Another point of concern is the linkage between the effectiveness measures and functional behaviour. We used several measurement instruments to examine the effectiveness of NTT. Improvement of the treated group in terms of outcome of movement (speed and accuracy) and quality of movement patterns was found. We were even able to find changes in the underlying motor processes while a very complex task was performed. More insight should be gained with regard to how the change in motor abilities influences the participation of children with DCD in, for example, activities at recess in the school yard. Does scoring within age norms mean that the problems are solved, and the child is cured? We found that the total impairment score of the M-ABC is associated to a child’s movement versatility during recess play (unpublished data; Kuiper et al., 1999). Those children performing below the 15th centile showed about 2 skills during their 15-minutes recess play, whereas their peers with better M-ABC scores exhibited on average 5 different skills. The present evaluation study shows that the tasks learned during NTT predict what aspects of the M-ABC test will be performed better than before treatment started. It also shows that transfer of skills to other skills is not likely to occur (chapter 3, Revie & Larkin,1993; Niemeijer et al., 2000). However, the main goal of NTT is not to teach a child to perform well in the therapy room only. Whether the improvements as can be measured with motor tests generalise to a child’s

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motor behaviour in daily life is unknown. Although observing children during recess play is very time-consuming, it is worthwhile to investigate how versatile the movements of children with DCD are before and after treatment of locomotor and ball skills. It will provide insight in whether treated children expand their motor vocabulary in daily life situations. While talking with parents of children in the controlled trial, I got the impression that they experienced progress of their children’s motor development in daily life. This impression might be biased, and therefore it would be worthwhile to be able to investigate it.

References Eccles MP, Grimshaw J, Campbell M, Ramsay C. (2003). Research design for studies

evaluating the effectiveness of change and improvement strategies. Quality & Safety in Health Care, 12:47-52.

Kavale KA, Mattson PD. (1983). ‘One jumped off the balance beam’: meta-analysis of perceptual-motor training. Journal of Learning Disabilities, 16:165-173.

Kuiper D, Niemeijer AS, Reynders K. (1999). Movement versatility in children with movement problems (poster). DCD IV Developmental Coordination Disorder, from research to diagnostics and intervention. 4th biennial workshop on children with a Developmental Coordination Disorder, The Netherlands; Groningen, p. 60.

Mandich AD, Polatajko HJ, Macnab JJ, Miller LT. (2001). Treatment of children with Developmental Coordination Disorder: what is the evidence? Physical & Occupational Therapy in Pediatrics; 20:51-68.

Martini R. Polatajko HJ. (1998). Verbal self-guidance as a treatment approach for children with developmental coordination disorder: A systematic replication study. Occupational Therapy Journal Research, 18:157-181.

Niemeijer AS, Schoemaker MM, Smits-Engelsman BCM. (2000). De behandeldoelen in relatie tot het effect van fysiotherapie bij kinderen met schrijfproblemen. Tijdschrift van de Nederlandse Vereniging voor Fysiotherapie in de Kinder- en Jeugdgezondheidszorg (NVFK) [Journal of the Dutch Peadiatric Physiotherapy Association] , 27:6-9.

Niemeijer AS, Schoemaker MM, Smits-Engelsman BCM. (2003). Kinderen met developmental coordination disorder: welke kinderen krijgen hulp in de eerstelijnskinderfysiotherapie? Tijdschrift voor Kindergeneeskunde, [Jounal for Peadiatric Medicine], 71:197-202.

Revie G, Larkin D. (1993). Task specific intervention with children reduces movement problems. Adapted Physical Activity Quarterly, 10;29-41.

Schmidt RA, Lee TD. (1999). Motor Control and Learning: a Behavioral Emphasis. Champaign, Ill: Human Kinetics.

Schoemaker MM (1992). Physiotherapy for clumsy children. An effect evaluation study. PhD thesis, University of Groningen, the Netherlands.



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Schoemaker MM, Hijlkema MGJ, Kalverboer AF. (1994). Physiotherapy for clumsy children: an evaluation study. Developmental Medicine and Child Neurology, 36:143-155.

Schoemaker MM, Niemeijer AS, Reynders K, Smits-Engelsman BCM. (2003). Evaluation of the effectiveness of Neuromotor Task Training for children with Developmental Coordination Disorder - a pilot study. Neural Plasticity, 10:155-163.

Sigmundsson H, Hopkins B. (2005). Do ‘clumsy’ children have visual recognition problems? Child: Care Health and Development; 31:155-158.

Van Waelvelde H, De Weerdt W, De Cock P, Smits-Engelsman BCM. (2004). Association between visual perceptual deficits and motor deficits in children with developmental coordination disorder. Developmental Medicine and Child Neurology, 46:661-666.

Wright HC, Sugden DA (1998). A school based intervention programmes for children with developmental coordination disorder. European Journal of Physical Education, 3:35-50.

11- Niemeijer - Chapter 8 summary

Summary



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espite normal intelligence, about 5 to 10% of school-aged children have difficulty adequately performing movement tasks that are part of their daily routine. Examples of such tasks are tying shoelaces, buttoning, eating neatly,

bicycling, playing ball, climbing stairs, swimming, but also drawing and handwriting. Because of their motor difficulties, children might not get asked to play by peers, or they might withdraw from leisure activities because they feel they lack sufficient skills to enjoy participating. The term which is fast becoming internationally accepted to describe the motor difficulties of these children, is developmental coordination disorder (DCD; APA, 1987; 2000). It can be used when the motor difficulties cannot be explained by any other medical condition or mental retardation, yet they are severe enough to interfere with activities of daily living. There is a strong need for intervention as, contrary to what lay people, teachers and healthcare professionals often believe, most children with DCD do not outgrow their problems (Cantell et al., 1994; Christiansen, 2000; Geuze & Borger, 1993; Hellgren et al., 1993; Losse et al., 1991). Lack of practice, due to not participating in physical activities, may inhibit further motor development, possibly aggravating existing performance differences between a child with DCD and its peers. In addition, DCD can influence behavioural development or increase the long-term risk of chronic disease (Peters et al., 2004). General practitioners (GPs), when consulted by parents about a child’s poor motor performance, may refer the child to a paediatric physiotherapist (PPT). PPTs can draw on an array of treatment approaches. Evidence for the effectiveness of treating children with DCD, however, is scarce. Dutch physiotherapists often use what they have learned on various courses in an eclectic fashion (Schoemaker et al., 1994). Instead of practising functional skills, treatment focuses on prerequisites which are believed necessary for adequate task performance. As the effectiveness of the treatment provided in the past has been disappointing (Mandich et al., 2001; Pless & Carlsson, 2000), we developed a new treatment approach called Neuromotor Task Training (NTT). Neuromotor Task Training (NTT) was developed especially for children with DCD. NTT incorporates recent scientific knowledge on the variables affecting motor control and motor learning in order to enhance motor learning in general, in particular as regards the transfer of skills to activities of daily living. Special attention is paid to the best ways to give instruction and feedback. The treatment programme is child-centred and mainly task-oriented, focusing strictly on teaching those skills that a child needs in daily life. The tasks selected are different for each child, depending on its individual needs as well as the expectations, capabilities and motivation of both the child and its parents/carers. In training functional skills, it is assumed that therapists stimulate deficient motor control processes. The higher the resemblance between the treatment situation and the circumstances in which the skills are needed in daily life, the more successful the transfer of skills practised to daily life activities.

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The main objective of this thesis was to evaluate Neuromotor Task Training. Because NTT is task-oriented and pays special attention to the question of how children are taught motor skills, we also wanted to gain an understanding of the assumed intervening mechanisms of NTT (opening the black box).

A controlled trial We conducted a controlled trial to investigate whether NTT was effective for children suffering from DCD. For this trial, 40 paediatric physiotherapists (PPTs) who had received instruction in NTT during their three-year professional training followed two extra refreshers sessions that were organised especially for this study. The participation of a fairly large number of therapists was expected to enhance the external validity of our results. Two groups of children with DCD (6-10 years) were recruited: a treatment group and a non-treatment control group. The treatment group consisted of children who had been referred to physiotherapy by their GPs and who received either 9 or 18 ‘weekly’ 30-minute sessions of NTT. We recruited children for the non-treatment control group by putting up posters in ordinary primary schools, offering free motor testing of children for parents concerned about their children’s motor development. This non-treatment group was tested twice with a 3-month interval. The results of this group were used to control for possible testing effects and spontaneous development. The two groups of children were not randomly selected because parents would not have been willing to participate if there had been a chance that their child would have been put on a hypothetical waiting list. Moreover, because PPTs regarded their treatment as effective, they felt it was unethical to withhold treatment when a child was referred to them. To ensure internal validity, inclusion criteria were formulated to make the groups of children as homogeneous as possible. One possibly important difference nevertheless remained: parents of the children in the control group had not – as yet – tried to access professional help. It is likely, therefore, that there was a difference between the two groups, that might be reflected in the spontaneous rate of development. In chapter 2, we describe how we tried to get more insight into why some parents – in this case, of children in the treatment group – had arranged treatment for their children, while others had not. In order to study the use of special care services, we used a model developed by Andersen and Newman (1973). In a study, not published in this thesis, we found no differences in children’s social background (including parents’ educational level), living environment, or the age at which motor milestones were reached (Niemeijer et al., 2003).We did not think that enabling factors were relevant for the difference in use of care between the groups because nearly everyone in the Netherlands has healthcare insurance and there is a good spread of services throughout the country, with equal quality of care and equal pricing. We therefore compared the



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health needs (motor and behavioural symptoms) of both groups of children more closely. Although the groups performed equally poorly on the Movement Assessment Battery for Children (M-ABC; Henderson & Sugden, 1992), a popular general motor test to select children with DCD (Geuze et al., 2001), we found that the nature of the difficulties differed. Children in the control group had more difficulty with manual dexterity, but better ball skills and better quality of movement patterns compared to the treatment group. Children in both groups displayed similar socio-emotional behaviour, although the control group did have a stronger tendency to internalise problems. We concluded that, despite differences in the nature of the difficulties, children in the two groups did not differ and had the same need for physiotherapy. In chapter 3, we give an analysis of the pretest and posttest scores of children with an M-ABC pretest score in or below the 15th centile. We used scores on the M-ABC (Henderson & Sugden, 1992) and the Test of Gross Motor Development-2 (TGMD-2; Ulrich, 2000) as measures of motor performance. The non-treatment group showed no improvement on the M-ABC after a 3-month period, while their average TGMD-2 score actually deteriorated. The treatment group, however, did make remarkable progress. These results indicate that motor performance does not improve spontaneously in a 3-month period and that NTT is effective. We found that the positive effects of NTT, a mainly task-oriented approach, were most pronounced in tasks that were comparable to the tasks trained. We also explored whether other child-related characteristics influenced the success of NTT. Older children with poorer motor patterns had benefited more from NTT. Although, many children scored high on the attention problems scale (Child Behaviour Checklist, CBCL; Achenbach, 1991), the severity of attention problems was not associated with NTT’s effectiveness. The degrees to which children were withdrawn, had thought problems, were anxious/depressed, or showed signs of delinquency (subscales of the Child Behaviour Checklist) did show low but statistically significant associations with the degree of success achieved with NTT, but PPTs were nevertheless able to bring about positive changes in children’s motor performance. To find out whether participating therapists were actually following the NTT guidelines regarding the best ways to give instruction and feedback when treating the children, we observed videotaped treatment sessions. The tool used, the Motor Teaching Principle Taxonomy (MTPT), is described in chapter 4. The MTPT enables systematic observation of a therapist’s verbal actions aimed at enhancing motor learning. In the MTPT, we distinguished three categories of teaching principles used by therapists: ‘giving instruction’, ‘providing or asking feedback’, and ‘sharing knowledge’. The MTPT’s reliability and validity were satisfactory. Through our observations, we found that therapists were treating children according to NTT’s guidelines for motor teaching. Therapists’ gave instructions most frequently. In addition, the frequency with which the principles were used showed little correlation with the children’s initial

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motor performance level, indicating that the choice of principle was not related to the child’s entry level. Since the actions of therapists were aimed at improving motor performance, we examined whether the frequency of their use was associated with treatment success after 9 or 18 sessions (chapter 5). We found that actions clustered as principle ‘providing clues on how to perform a task’ (a way of giving instruction), ‘asking children about their understanding of a task’, and ‘explaining why a movement should be executed in a certain way’ (ways of sharing knowledge) were significantly associated with improved motor performance. In the light of these results, it would be worthwhile to carry out more research, with larger sample sizes, into the relationships between the assumed intervening mechanisms of NTT, such as the therapist’s actions, the children’s behavioural characteristics, and the degree of success of NTT.

Changes in grapho‐motor behaviour In another study, we evaluated the effectiveness of NTT in children with grapho-motor problems. The research described in chapters 2 to 5 were based mainly on general motor tests to select children or evaluate NTT. But one of the most common reasons for remediation is problems with handwriting. Handwriting is a very complex fine motor skill, and children with poor grapho-motor ability might thus form a specific subgroup of children with DCD. The DSM-IV explicitly mentions handwriting as an example of daily motor activities which pose difficulties for children with DCD (APA, criterion A).In chapter 6, therefore, we describe a study in which we selected children with DCD on the basis of poor grapho-motor ability. To evaluate NTT for this group, we used the Concise Assessment Method for children's handwriting (BHK; Hamstra-Bletz et al., 1987) to assess handwriting quality, and one of the manual dexterity test items (the flower trail) of the M-ABC (Henderson & Sugden, 1992). Besides changes in the outcome on the flower-trail drawing item, we wanted to gain insight into changes in the underlying drawing process brought about by NTT. For this reason, the children performed the flower-trail item on an XY-digitizer. After 3 months of NTT, their quality of handwriting, writing speed and accuracy had improved. We also found changes in the underlying writing process. The children were drawing more fluently and lifted their pen from the paper less often. These results indicate that the children with poor handwriting had learned to use their typical movement strategy in a more effective way.

Conclusion Our sample sizes were sufficiently large to show that NTT is an effective treatment approach for children with DCD. Children in the treatment groups showed improved motor performance on several tests, whereas a non-treatment control group remained stable or even deteriorated in a 3-month period. Detailed information on what took



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place during the 30-minute sessions of NTT (the ‘black box’) revealed that children improved most on tasks comparable to those trained. The strategies therapists used in teaching the children were also associated with the degree of treatment success. As NTT, which was developed especially for children with DCD, has been found to be an effective treatment approach, we urge other physiotherapists to start treating children with DCD according to the NTT guidelines, too.

References Achenbach TM. (1991). Manual for the Child Behavior Checklist/4-18 and 1991 profile.

Burlington: University of Vermont. American Psychiatric Association. (2000). Diagnostic and statistical manual of mental

disorders (4th ed, text revision.). Washington, DC: Author. American Psychiatric Association. (1987). Diagnostic and statistical manual of mental

disorders (3th ed, text revision.). Washington, DC: Author. Andersen RM, Newman JF. (1973). Societal and individual determinants of medical care

utilization in the United States. Milbank Memorial Fund Q 51: 95-124. Cantell MH, Smyth MM, Ahonen TP. (1994). Clumsiness in adolescence: educational

motor and social outcomes of motor delay detected at 5 years. Adapted Physical Activity Quarterly, 11:115-129.



Geuze R, Jongmans MJ, Schoemaker M, Smits-Engelsman B. (2001). Clinical and research diagnostic criteria for developmental coordination disorder: a review and discussion. Human Movement Science, 20:7-47.

Hamstra-Bletz, E., De Bie, J., & den Brinker, B.P.L.M. (1987). Beknopte beoordelingsmethode voor kinderhandschriften [The concise assessment method for children’s handwriting]. Lisse: Swets and Zeitlinger


Henderson SE, Sugden D. (1992). Movement Assessment Battery for Children; manual. Sidcup, Kent: The psychological Corporation.

Losse A, Henderson SE, Elliman D, Hall D, Knight, E, Jongmans, M. (1991). Clumsiness in children –do they grow out of it? A 10-year follow-up study. Developmental Medicine and Child Neurology, 33:55-68.

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Niemeijer AS, Schoemaker MM, Smits-Engelsman BCM. (2003). Kinderen met een developmental coordination disorder: welke kinderen krijgen hulp in de eerstelijnskinderfysiotherapie? Tijdschift voor Kindergeneeskunde [Journal of paediatric medicine], 71:197-202.

Peters JM, Henderson SE, Dookun D. (2004). Provision for children with developmental co-ordination disorder (DCD): audit of the service provider. Child: care, health and development, 30:463-479.



Ulrich DA. (2000). Test of Gross Motor Development, Second Edition, examiner's manual. Austin, TX: Pro-Ed.



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uiten spelen, meedoen in de gymles, veters strikken, knopen dichtdoen, eten zonder te knoeien/morsen, of netjes en vlot schrijven lijken allemaal vanzelfsprekende activiteiten. Maar het blijkt dat ongeveer 5-10% van de

kinderen op reguliere basisscholen bij dergelijke dagelijkse activiteiten problemen ondervindt. Sinds midden jaren 90 bestaat er consensus om deze kinderen aan te duiden als kinderen met een developmental coordination disorder (DCD: APA, 1987; 2000). DCD is een Engelse term voor een lichte motorische ontwikkelingsstoornis. De meeste kinderen met DCD groeien niet over hun problemen heen (Cantell e.a., 1994; Christiansen, 2000; Geuze & Borger, 1993; Hellgren e.a., 1993; Losse e.a.., 1991) terwijl dat wel vaak wordt gedacht. Het is zelfs zo dat het motorische ontwikkelingsniveau van deze kinderen steeds meer gaat afwijken van het niveau van hun leeftijdsgenoten en vaak gepaard gaat met andere problemen (bijvoorbeeld aandachtsproblematiek of sociaal negatief gedrag). Hierdoor neemt de kans op chronische aandoeningen toe (Peters e.a., 2004). Al met al reden genoeg om kinderen met DCD te behandelen. Ouders met vragen over de motorische ontwikkeling van hun kind kunnen, met of zonder verwijzing van de huisarts, terecht bij een kinderfysiotherapeut. De kinderfysiotherapeuten beschikken over verschillende behandelmethoden. Echter het effect van de behandeling van kinderen met DCD is veelal teleurstellend (Mandich e.a., 2001; Pless & Carlsson, 2000). Daarom hebben wij een nieuwe behandelmethode ontwikkeld, genaamd Neuromotor Task Training (NTT). Neuromotor Task Training (NTT) is in aanvang speciaal ontwikkeld voor de behandeling van kinderen met DCD. NTT is gebaseerd op recente motorische controle en motorische leertheoriëen zodat de kans op verbetering en uiteindelijke toepassing van het geleerde in de dagelijkse praktijk, geoptimaliseerd wordt. Binnen NTT is er ook speciale aandacht voor de wijze waarop het beste instructies en feedback gegeven kunnen worden. In een behandeling met NTT staat het kind centraal en worden voornamelijk dagelijkse vaardigheden geoefend. Terwijl het kind zich deze vaardigheden eigen leert maken, worden ook motorische processen getraind die mogelijk niet optimaal verlopen. Om de kans te vergroten dat het geleerde uiteindelijk ook zonder toezicht van de kinderfysiotherapeut wordt toegepast, wordt een vaardigheid zo geoefend dat de situatie zoveel mogelijk lijkt op de situaties in het dagelijks leven. Het hoofddoel van dit proefschrift is het evalueren van NTT. Omdat NTT taak-georiënteerd is en aandacht schenkt aan de wijze waarop geïnstrueerd wordt, willen we ook inzicht verkrijgen in de veronderstelde werkingsmechanismen van NTT. Twee evaluatieonderzoeken zijn verricht: (a) in een groot landelijk onderzoek zijn de effecten van NTT in het algemeen in kaart gebracht, en (b) in een subgroep van kinderen met DCD, namelijk geselecteerd op schrijfproblemen, is onderzocht of er ook veranderingen optreden in de onderliggende motorische processen.

B

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Landelijk onderzoek Voor de evaluatie van NTT als behandelmethode voor kinderen met DCD zijn 40 kinderfysiotherapeuten, van Groningen tot Zeeland, bereid gevonden om medewerking te verlenen aan een quasi-experimenteel onderzoek. Zij zijn geïnstrueerd in NTT tijdens hun opleiding als kinderfysiotherapeut (veelal Avans+ te Breda), en tijdens twee extra bijeenkomsten. Het feit dat meerdere therapeuten hebben geparticipeerd in het onderzoek zal uiteindelijk de zeggingskracht van de resultaten verhogen. Twee groepen kinderen met DCD (6-10 jaar) zijn gerecruteerd: een behandelde en een onbehandelde controle groep. De behandelde groep bestond uit kinderen die recent verwezen waren naar kinderfysiotherapie. Zij zijn 9 of 18 keer behandeld met NTT (‘wekelijkse’ 30-minuten sessies). De ouders van de kinderen in de onbehandelde controle groep hebben gereageerd op een poster die verspreid is op reguliere basisscholen. De poster roept ouders op om, indien zij twijfelen aan de motorische ontwikkeling van hun kind, hun kind (gratis) te laten testen met een tussenpoos van ongeveer 3 maanden. De resultaten van deze controle groep worden in het onderzoek gebruikt om te kunnen corrigeren voor mogelijke test-hertest effecten of spontane ontwikkeling. Het is mogelijk dat beide groepen kinderen verschillen, omdat zij niet ‘at random’ zijn geselecteerd. Om te waarborgen dat de groepen op belangrijke kenmerken hetzelfde zullen zijn, en vergelijking met anderen onderzoeken waarin kinderen met DCD zijn bestudeerd mogelijk te maken, zijn inclusiecriteria opgesteld. Aangezien de ouders van de kinderen in de controle groep nog geen professionele hulp hebben ingeschakeld, zijn verschillen tussen beide groepen wel aannemelijk en dit kan invloed hebben op de spontane ontwikkelingssnelheid. In hoofdstuk 2 hebben we onderzocht waarom de ene groep wel en de andere geen speciale hulp kreeg. We hebben daarvoor een model van Andersen en Newman (1973) gebruikt. In eerdere analyses hebben wij geen verschillen gevonden tussen de groepen in de sociale achtergronden (o.a. het opleidingsniveau van de moeder/vader), de leefomgeving, of de leeftijd waarop belangrijke motorische mijlpalen werden bereikt (Niemeijer e.a., 2003). Ook zogenaamde ‘enabling factors’ zijn volgens ons niet relevant, omdat vrijwel iedereen in Nederland voldoende verzekerd is, en er overal voldoende zorgaanbod is. Daarom zijn de ‘health needs’ (symptomen) uiteindelijk nader bestudeerd aan de hand van de Movement Assessment Battery for Children (M-ABC; Henderson & Sugden, 1992), de Test of Gross Motor Development-2 (Ulrich, 2000). en de Child Behaviour Checklist (CBCL; Achenbach, 1991). Op de M-ABC, een algemene motoriektest die veel gebruikt wordt om de ernst van de problemen te bepalen (Geuze e.a., 2001), is gebleken dat de groepen even slecht presteerden. Echter, de aard van de problemen is wel verschillend: kinderen in de controle groep hebben meer problemen met handvaardigheidstaken en beschikten over betere balvaardigheden (M-ABC). Tevens zijn hun bewegingen van betere kwaliteit (TGMD-2). Op sociaal-emotioneel gebied verschillen de groepen niet (CBCL), al lijken de kinderen in de controle groep



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hun problemen iets vaker te internaliseren. We concluderen dat de ernst van de problematiek niet verschilt, en dat de objectieve behoefte aan therapie in beide groepen even groot is. In hoofdstuk 3, wordt de effectiviteit van NTT bestudeerd. Alleen de gegevens van kinderen die tijdens de voormeting onder het 15e percentiel (1 SD) op de M-ABC hebben gescoord zijn hiervoor gebruikt. Aan de hand van de M-ABC en de TGMD-2 zijn de motorische prestaties van de kinderen beoordeeld. Na een periode van bijna 3 maanden is de controle groep niet anders gaan scoren op de M-ABC, en op de TGMD-2 presteerde zij slechter. De behandelde groep is echter wel vooruit gegaan op beide testen. De resultaten tonen dat NTT werkt en de motoriek van kinderen met DCD zich zonder hulp niet ontwikkelt. De positieve effecten van NTT treden vooral op tijdens het uitvoeren van taken die lijken op de taken die geoefend zijn. Daarnaast hebben wij onderzocht of bepaalde kindkenmerken de mate van effectiviteit beïnvloeden. Ook al is gebleken dat veel kinderen aandachtsproblemen hebben, is aandacht niet een factor die invloed had op de mate van het succes van NTT. Wel is gebleken dat oudere kinderen meer profiteerden van NTT. Tevens is de mate waarin kinderen teruggetrokken waren, denkproblemen hadden, angstig/depressief waren of tekenen van delinquent gedrag vertoonden (allen CBCL symptoom schalen) statistisch gezien van invloed op de mate van vooruitgang door NTT. Echter, de invloed van deze gedragskenmerken is klein. Therapeuten zijn ondanks de aanwezigheid van deze kenmerken in staat gebleken om positieve veranderingen in de motoriek van de kinderen te bewerkstelligen. Om te achterhalen of therapeuten behandelen volgens de richtlijnen van NTT met betrekking tot het motorisch leren, hebben we behandelsessies op video vastgelegd (hoofdstuk 4). De Motor Teaching Principles Taxonomy (MTPT) is ontwikkeld om op een systematische wijze de verbale uitingen van therapeut die bedoelt zijn om het motorisch leren te bevorderen in kaart te brengen. De taxonomie omvat drie categorieën; instructies geven, het geven of vragen van feedback en het delen van kennis over bewegen. De taxonomie is voldoende betrouwbaar en valide. De resultaten van de observaties laten zien dat therapeuten behandelden volgens richtlijnen van NTT. Instructies worden het meest gegeven. Tevens is gebleken dat de frequentie waarmee bepaalde leerprincipes gehanteerd worden niet samenhangt met de motorische prestaties tijdens de voormeting. Aangezien de verbale uitingen van de therapeuten bedoeld zijn om het motorisch leren te bevorderen, hebben we onderzocht of er wèl een verband bestaat tussen de frequentie waarmee ze gehanteerd worden en de vooruitgang die bij de kinderen is gemeten (hoofdstuk 5). Hoe vaker de therapeuten tips hebben gegeven over hoe een taak uit gevoerd kan worden, hebben gevraagd of de kinderen de taak hebben begrepen, en hebben uitgelegd waarom een beweging op een bepaalde manier uitgevoerd zou moeten worden, hoe meer vooruitgang bij de kinderen is waargenomen. Er is echter meer onderzoek nodig om ook inzicht te krijgen in de interacties tussen de veronderstelde werkingsmechanismen van NTT.

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Onderzoek naar schrijfproblemen In hoofdstuk 6, hebben we het effect van NTT geëvalueerd bij kinderen die gediagnostiseerd zijn als kinderen met DCD gebaseerd op grafomotorische problemen. Schrijven is een zeer complexe fijne motorische vaardigheid, en is een van de meest genoemde redenen om professionele hulp in te schakelen. De effecten van NTT zijn gemeten aan de hand van de Beknopte Beoordelingsmethode voor Kinderhandschriften (BHK; Hamstra-Bletz e.a., 1987) en een van de handvaardigheidsitems van de M-ABC, namelijk het bloemenspoor. Na therapie is de kwaliteit en snelheid van het schrijven toegenomen. Het bloemenspoor hebben we op een schrijftableau laten intekenen. Hierdoor kunnen wij niet alleen concluderen dat de behandelde groep na therapie minder vaak buiten de lijntjes heeft getekend, maar ook dat er veranderingen in het onderliggende proces zijn opgetreden. De kinderen zijn vloeiender gaan schrijven en hebben de pen beter op het papier gehouden. Wij kunnen concluderen dat er niet alleen veranderingen zijn opgetreden in de uitkomst van bewegen, maar ook het onderliggende motorische proces.

Conclusie NTT is een effectieve behandelmethode voor kinderen met DCD. Na een periode van ongeveer 3 maanden is de behandelde groep beter gaan presteren op meerdere motorische tests, terwijl de niet behandelde controle groep stabiel is gebleven, of zelfs achteruitging. Informatie over wat er is gebeurd tijdens de therapie (de zogenaamde ‘black box’) toont dat kinderen vooral beter zijn gaan presteren op taken die lijken op de taken die tijdens NTT geoefend zijn. De effecten van NTT zijn dus niet algemeen, maar specifiek. Ook de manier waarop therapeuten lesgeven blijkt samen te hangen met het succes van de behandeling. Omdat NTT speciaal is ontwikkeld voor kinderen met DCD, en omdat de methode effectief is gebleken, pleiten wij ervoor dat ook andere kinderfysiotherapeuten kinderen gaan behandelen volgens de richtlijnen van NTT.

Referenties Achenbach TM. (1991). Manual for the Child Behavior Checklist/4-18 and 1991 profile.

Burlington: University of Vermont. American Psychiatric Association. (2000). Diagnostic and statistical manual of mental

disorders (4th ed, text revision.). Washington, DC: APA. American Psychiatric Association. (1987). Diagnostic and statistical manual of mental

disorders (3th ed, text revision.). Washington, DC: APA. Andersen RM, Newman JF. (1973). Societal and individual determinants of medical care

utilization in the United States. Milbank Memorial Fund Quarterly, 51:95-124. Cantell MH, Smyth MM, Ahonen TP. (1994). Clumsiness in adolescence: educational

motor and social outcomes of motor delay detected at 5 years. Adapted Physical Activity Quarterly, 11:115-129.



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Geuze R, Jongmans MJ, Schoemaker M, Smits-Engelsman B. (2001). Clinical and research diagnostic criteria for developmental coordination disorder: a review and discussion. Human Movement Science, 20:7-47.

Hamstra-Bletz E, De Bie J, den Brinker BPLM. (1987). Beknopte beoordelingsmethode voor kinderhandschriften. Lisse: Swets and Zeitlinger.


Henderson SE, Sugden D. (1992). Movement Assessment Battery for Children; manual. Sidcup, Kent: The psychological Corporation.

Losse A, Henderson SE, Elliman D, Hall D, Knight, E, Jongmans, M. (1991). Clumsiness in children –do they grow out of it? A 10-year follow-up study. Developmental Medicine and Child Neurology, 33:55-68.


Niemeijer AS, Schoemaker MM, Smits-Engelsman BCM. (2003). Kinderen met een developmental coordination disorder: welke kinderen krijgen hulp in de eerstelijnskinderfysiotherapie? Tijdschift voor Kindergeneeskunde, 71:197-202.

Peters JM, Henderson SE, Dookun D. (2004). Provision for children with developmental co-ordination disorder (DCD): audit of the service provider. Child: care, health and development, 30:463-479.



Ulrich DA. (2000). Test of Gross Motor Development, Second Edition, examiner's manual. Austin, TX: Pro-Ed.

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en promotieonderzoek kan niet worden uitgevoerd zonder de inzet, betrokkenheid en belangstelling van velen. Een woord van dank is hier dan ook op zijn plaats, al loop ik daarmee wel het risico om mensen te vergeten. Het idee

voor het onderzoek dat ik heb mogen uitvoeren ontstond namelijk al vele jaren geleden. In 1993 startte ik met onderzoek naar de effecten van fysiotherapie bij kinderen met schrijfproblemen. Dit gebeurde onder bezielende begeleiding van Marina Schoemaker, die toen nog werkzaam was bij de ontwikkelings- en experimentele psychologie (RUG). Ik was in die tijd ook geregeld in Nijmegen te vinden om samen te werken aan het onderzoek met Marion Jansen. Marion en ik reden vaak nog rond half 10 ’s avonds in haar Pandaatje naar de uni (NICI, KUN). Daar stond Bouwien Smits-Engelsman dan klaar om ons weer eens te helpen in ons denkproces. Ongeveer vijf jaar later verkregen Marina en Bouwien subsidie van het College voor Zorgverzekeringen (toen nog Ziekenfondsraad) voor een grootschalig landelijk onderzoek; mijn promotieonderzoek. Beste Marina en Bouwien, jullie kozen mij als promovendus, en ik dank jullie voor het in mij gestelde vertrouwen. We kennen elkaar inmiddels al bijna 15 jaar! En nu ik dit dankwoord aan het schrijven ben realiseer ik me dat we veel hebben meegemaakt. Er is niet alleen op persoonlijk vlak van alles is gebeurd (zo kregen we alle drie (klein)kinderen), maar ook zakelijk is meetbare progressie opgetreden. Zo herinner ik me het promoveren van Bouwien, de benoeming tot UHD van Marina, en vervolgens de benoeming tot professor van Bouwien. Ik ben blij dat ik me dankzij jullie straks ook doctor mag noemen. Beste Bouwien, omdat je niet woont en werkt in Groningen, ben ik je extra dankbaar. In het contact met jou heb ik geen afstand ervaren. Je bent altijd in staat gebleken om te reageren op mijn vragen alsof je om de hoek zat. Bedankt! Een landelijk onderzoek naar de effecten van kinderfysiotherapie kan niet worden uitgevoerd zonder de medewerking van vele (erkende) kinderfysiotherapeuten. In het onderzoek blijven deze therapeuten anoniem, maar hier wil ik ze toch bij naam noemen: Yvonne Hanewinkel, Viola Hellinga, Hanneke Hoffmann (Friesland); Ellen Bilderbeek, Hannie Kroon (Groningen); Mariet Hijlkema, Marianne Kuijpens-Loeter (Drenthe); Michiel Bloemen, Annette van Eerden, Hannie Hendriks, Rietje Klappe, Anneloes Overvelde-Zeillemaker, Charlotte Vermeulen (Overijssel); Marjo Stevens, Ingrid Vrenken (Gelderland); Annemarie van de Ven, Katinka Poppelaars (Brabant); Marije Busschers (Utrecht); en Ineke van Greuningen (Zeeland). Al deze therapeuten waren overtuigd van het nut van hun dagelijks werk, en vertrouwden ons een blik toe in ‘hun keuken’. Zij stelden hun therapieruimte kosteloos ter beschikking voor de testmomenten, vonden ouders en kinderen bereid om mee te werken en rapporteerden over de therapiesessies. Therapeuten, ik dank jullie voor alle investeringen. Ouders en kinderen, jullie zullen wel anoniem blijven. Maar dat wil niet zeggen dat ik niet regelmatig aan jullie denk. Ik ben blij dat wij samen met de therapeuten het positieve effect van Neuromotor Task Training voor kinderen met een lichte motorische

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ontwikkelingsstoornis heb kunnen aantonen. En ik hoop dat jullie nog steeds positieve gevolgen van de therapie ervaren. Naast mijn directe begeleiders, de therapeuten en de kinderen zijn er natuurlijk nog veel meer mensen die bij hebben gedragen aan het feit dat ik mijn onderzoek nu afrond met een promotie. Ik zal de lezer van dit dankwoord meevoeren door de tijd. Toen ik werd aangesteld als promovendus trof ik op de Bloemsingel vele fijne collega’s. Een van hen was dr. Koop Reynders, voorzitter van de werkgroep Bewegingswetenschappen. Beste Koop, jij regelde voor mij een werkplek in het overvolle gebouw. Ik mocht intrekken bij jou op de kamer en een ommetje maken langs het secretariaat als je met onze ‘nog onbekende’ nieuwe hoogleraar belde. Van jou leerde ik veel over het bestuderen van het fysiotherapeutisch handelen en het ontwikkelen van een taxonomie. Met deze kennis ben ik een beetje in je voetsporen getreden. Ik dank je voor je inzet en enthousiasme. Mijn eerste promotor, prof. dr. Theo Mulder, werd aangesteld nadat ik reeds met mijn onderzoek was begonnen. Theo, bedankt dat je mijn eerste promotor wilde zijn. Tevens dank ik in het bijzonder Nettie Bulthuis (voor je luisterend oor), Marieke van Heuvelen (voor je gezelligheid en adviezen in verband met de Medisch Ethische Commissie) en Daphne Kuiper. Daphne, toen ik begon met mijn onderzoek deed jij ook onderzoek naar de motoriek van kinderen, maar dan binnen de lichamelijke opvoeding. Wat heb ik toch veel aan jou gehad! Ik denk met plezier terug aan onze inspirerende gesprekken op de vrijdagmiddag. Ik dank ook mijn toenmalige mede jonge-honden: Feyuna Jansma, Yldau Dijkstra, Johan de Jong, Marije (Elferink-)Gemser, en twee buiten-promovendi: Annette van der Putten, en Claudia Kruizinga. Lieve mensen, met veel plezier denk ik terug aan onze leuke (telefonische) wetenschappelijke discussies, en de sociale praatjes. Er zijn ook studenten geweest die een bijdrage hebben geleverd aan mijn promotieonderzoek (of een aanverwant onderzoek): ik noem onder andere Cornill Hospers, Liesbeth Hempenius, Karen Oldenziel, Janke Oosterhaven, Boukje Ummels. Allen dank! Janine Stubbe wil ik in het bijzonder bedanken. Janine, dankzij jou heeft tijdens mijn zwangerschap de dataverzameling niet stil gelegen. Ik wil je bedanken voor je grote inzet en voor het meebrengen van versnaperingen als we weer eens samen op pad gingen om kinderen te testen. Ik vind het fantastisch dat jijzelf nu ook gepromoveerd bent. Als ‘jeugdleider’ mag ik zeggen trots te zijn op mijn pupillen. Meerdere studenten zijn immers begonnen aan een promotieonderzoek. Tijdens mijn onderzoek verhuisde Bewegingswetenschappen van de Bloemsingel naar het AZG-terrein. Met die verhuizing kreeg ik andere collega’s, en werd ik ook een buiten-promovendus. Samen met Marije en een paar kamerplanten nam ik mijn intrek bij de zeer gastvrije Sandra Brouwer. Sandra, bedankt. Met Claudia kreeg ik een veel


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intensiever contact. Claudia, ik ben blij dat we, ook al woon je al weer een paar jaar in Nigeria, nog steeds vriendinnen zijn. Op de gang leerde ik ook de andere AIO’s van de afdeling Revalidatie kennen: Leontien Sturms, Rients Huitema, Bianca Nijhuis, Juha Hijmans en Wietske Kuijer. Beste (oud)mede-promovendi, wat hebben we veel meegemaakt. Heel erg bedankt voor de collegialiteit, adviezen, steun en gezelligheid. De afgelopen 2,5 jaar heb ik onderzoek verricht bij de disciplinegroep Klinische Farmacologie (KF) in samenwerking met de Huisartsgeneeskunde (HAG). Binnen beide groepen heb ik me welkom gevoeld. Ik dank dan ook alle HAG- en KF-medewerkers voor de fijne en inspirerende tijd. Veel medewerkers waren oprecht geïnteresseerd in mijn promotieonderzoek en stonden altijd klaar met raad en daad. Enkelen van hen hebben zelfs zeer concreet bijgedragen aan de totstandkoming van mijn proefschrift: Peter Mol , Jasperien van Doormaal, Rik Groenewegen, Klaas Groenier en Wessel Sloof. De leuke sfeer en collegialiteit die ik in deze periode heb ervaren zijn zeker belangrijk geweest voor mijn vermogen om dit promotieonderzoek af te ronden. Speciale dank gaat uit naar Jan Schuling (HAG), Adriaan van Doorn, Itte de Waard (beiden farmacotherapieonderwijs), en mijn kamergenoten Amany El Gazeryerly (CBG) en prof. dr. Gerrit Scherphof (emeritus hoogleraar Liposomen) voor de fijne tijd, en leerzame momenten. De lege plek die prof. Scherphof achterliet werd opgevuld door Frank Holtkamp (CBG). Frank, alle eer voor de omslag van dit boek komt jou toe. Binnen de KF behoorde ik tot de Rational Drug Use groep (ook onderdeel van het Noordelijk Centrum voor Gezondheidsvraagstukken, NCG); Ellen, Heidrun, Jaco, Jacoba, Jasperien, Larissa, Lianna, Peter, Petra, Ruth en Willeke, bedankt voor jullie collegialiteit! Deze groep wordt geleid door prof. dr. Floor M. Haaijer-Ruskamp. Beste Floor, jij hebt me opgenomen in jouw onderzoeksgroep en mij gemotiveerd om door te zetten. Jouw liefde voor de wetenschap is stimulerend. Ik heb veel van je geleerd. Hartelijk dank daarvoor. Er zijn naast de collega’s van Bewegingswetenschappen, de AIOs van Revalidatie, en de collega’s van KF/HAG ook nog andere professionals geweest die de afgelopen jaren een bijdrage hebben geleverd aan mijn proefschrift en aan wie ik dank verschuldigd ben. Voor mijn statistische vragen kon ik niet alleen terecht bij Marieke van Bewegingswetenschappen, maar ook bij Marijtje van Duijn. Marijtje, bedankt dat ik met je mocht sparren over mijn onderzoek. Zelfs de telefoontjes met jou in Seattle waren zeer verhelderend en open van karakter. Ook Hilde Tobi dank ik voor haar adviezen en suggesties met betrekking tot mijn artikelen. En omdat artikelen en een proefschrift geschreven dienen te worden in het Engels, wil ik mijn vriendin, Danielle de Calonne, bedanken. Danielle, jij bent altijd bereid om mijn twijfels over Engelse woorden of uitdrukkingen weg te nemen. Ook Heleen Reinders, waarmee ik al sinds 1994 bevriend ben, mag niet onvermeld blijven. Heleen, ook jij hebt bijgedragen aan de voortgang van

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mijn onderzoek. Ik vind het jammer dat ik de laatste jaren minder actief ben geweest binnen de revalidatie, maar een mens kan niet alles. Al die jaren heeft Truus van Ittersum-Gritter me geholpen in het bijhouden van de literatuur omtrent DCD (en de behoefte van artsen aan informatie over geneesmiddelen). Truus, je was meer voor mij dan de documentaliste van het NCG (binnenkort Graduate School SHARE). Ik wil je danken voor je goede adviezen en de vele uitdraaien met referenties. Uiteraard zijn er nog veel meer mensen die de afgelopen jaren belangrijk zijn geweest; niet alleen alle andere (oud-)collega’s en professionals die ik niet genoemd heb, maar ook het thuisfront: mede-hofbewoners, vrienden, familie en mijn gezin. Twee mensen heb ik gevraagd om mijn paranimf te zijn: Ingrid en Mark. Ingrid, ik hoop dat je altijd bij belangrijke momenten in mijn leven zult zijn. Je bent een heel fijne vriendin. Mark, mijn grote broer. Tijdens mijn promotieonderzoek kwam je weer in Nederland, en zelfs in Groningen wonen. Al spreken we elkaar niet veel, je bent er wel altijd voor mij. En in de slotfase van mijn promotieonderzoek heb je nog een waardevolle bijdrage geleverd ook. Ik vind het fijn dat jij ook deze dag achter mij zult staan. Wie ik natuurlijk niet onvermeld kan laten zijn de mensen die er altijd voor mij zijn (waren): mijn moeder († 2000), mijn vader en Roelie, en mijn schoonouders. Bedankt dat jullie altijd een luisterend oor hebben en er voor ons zijn. Na jaren werken heb ik meer artikelen dan mijn moeder. Zij wist dat het niet gemakkelijk is, maar wel heel fijn als het lukt om je naam in een internationaal tijdschrift te krijgen. Ik weet zeker dat ze trots op me zou zijn Lars en Esther, mijn beide schatten van kinderen, ik hoop dat jullie niet te veel hebben gemerkt van het feit dat ik dit proefschrift heb afgerond naast mijn baan bij de KF. En nee, Lars, het was geen glijbaan, maar wel leuk en leerzaam. Ik ben verheugd dat Lars zo enthousiast heeft meegedacht over de kaft van mijn boekje, en dat Esther nog net op de valreep weer een motorische vaardigheid onder de knie heeft gekregen: ze heeft leren fietsen zonder zijwieltjes! Hoe trots (en bezorgd) kan een moeder zijn? Henk Jan, jij komt als laatste aan bod in dit dankwoord. Je hebt dit project van begin tot eind meegemaakt, met alle ups and downs. Van ’s ochtends zeer vroeg samen naar een praktijk in Almelo, tot en met het ritje naar de drukker. Onvermoeibaar sta je altijd voor me klaar. Bedankt. Lieverd, het is af.

Anuschka S. Niemeijer, 1 mei 2007


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14- Niemeijer - chapter 11 CV

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nuschka Niemeijer werd op 21 augustus 1970 geboren te Delft. Na het behalen van haar VWO diploma studeerde zij Bewegingswetenschappen aan de Rijksuniversiteit Groningen. Gedurende deze studie werkte zij als student-

assistent bij de vakgroep Medische Fysiologie. Haar afstudeeronderzoek betrof de evaluatie van fysiotherapie voor kinderen met schrijfproblemen. Door dit onderzoek raakte zij geïnteresseerd in complexe gedragsproblemen en de psycho-sociale problematiek van mensen met een beperking, en daarom startte zij tevens met de universitaire opleiding Psychologie. Haar hoofdrichting werd de ontwikkelings- en experimenteel klinische psychologie. Als stagiair werkte zij aan de Hart de Ruyterschool, een VSO-school te Groningen verbonden aan het Pedologisch Instituut PINN. Daarnaast werkte zij als student-assistent in de Methodologiewinkel van de sociale faculteit, analyseerde zij gegevens van het landelijke Don Quichote project naar de beschikbaarheid van donororganen/weefsels en gaf zij statistiekles in Nijmegen en Breda. In 1998 studeerde zij af als ontwikkelingspsycholoog met drie nevenrichtingen: Bio/Neuropsychologie, Klinische Psychologie en Methodologie. Vervolgens verrichte zij als Assistent in Opleiding bij het Centrum voor Bewegingswetenschappen gedurende vier jaren promotieonderzoek naar de effecten van kinderfysiotherapie bij kinderen met een developmental coordination disorder. Van 2004 tot 2007 werkte zij als onderzoeker bij de disciplinegroep Klinische Farmacologie in samenwerking met Huisartsgenees-kunde (Noordelijk Centrum voor Gezondheidsvraagstukken (NCH), Universitair Medisch Centrum Groningen). Zij onderzocht de informatiebehoefte van artsen rondom hun geneesmiddelkeuze voor het College van Zorgverzekeringen. Anuschka heeft, samen met haar partner Henk Jan Vosselman, een zoon en een dochter die geboren werden in 2001 en 2004.

Lijst van gepubliceerde artikelen/hoofdstukken binnen het werkveld van de Bewegingswetenschappen Niemeijer AS, Smits-Engelsman BCM, Schoemaker MM. (2007). Neuromotor Task

Training for children with developmental coordination disorder: a controlled trial. Developmental Medicine & Child Neurology, 49: 406-411.

Niemeijer AS, Schoemaker MM, Smits-Engelsman BCM. (2006). Are teaching principles associated with improved motor performance in children with developmental coordination disorder? A pilot study. Physical Therapy, 86: 1221-1230.

Niemeijer AS, Smits-Engelsman BCM, Reynders K, Schoemaker MM. (2003). Verbal actions of physiotherapists to enhance motor learning in children with DCD. Human Movement Science, 22: 567-581.

Schoemaker MM, Niemeijer AS, Reynders K, Smits-Engelsman BCM. (2003). Evaluation of the effectiveness of Neuromotor Task Training for children with developmental coordination disorder-a pilot study. Neural Plasticity, 10: 155-163.

A

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Niemeijer AS, Schoemaker MM, Smits-Engelsman BCM. (2003). Kinderen met developmental coordination disorder: welke kinderen krijgen hulp in de eerstelijns-kinderfysiotherapie? Tijdschrift voor Kindergeneeskunde, 71: 197-202.

Reynders K, Niemeijer AS, Schoemaker MM, Smits-Engelsman BMC. (2003). Children with developmental co-ordination disorder (DCD): evaluating educational and therapeutical aspects of the intervention. In M. Dinold, G. Gerver & TK Reineld (Eds), Proceedings of 13th International Symposium. "Towards a Society for All" - through Adapted Physical Activity. Wien: Manz Verlag Schulbuch, p. 302-307.

Smits-Engelsman BCM, Niemeijer AS, van Galen GP. (2001). Fine motor deficiencies in children diagnosed as DCD based on poor grapho-motor ability. Human Movement Science, 20: 161-182.

Niemeijer AS, Schoemaker MM, Smits-Engelsman BCM. (2000). De behandeldoelen in relatie tot het effect van fysiotherapie bij kinderen met schrijfproblemen. Tijdschrift van de Nederlandse Vereniging voor Fysiotherapie in de Kinder- en Jeugdgezondheidszorg (NVFK), 27: 6-9.

Kuiper D, Niemeijer AS, Reynders K. (2000). Toepasbaarheid van de Test of Gross Motor Development in Nederland: een exploratief onderzoek. Bewegen & Hulpverlening, 17: 3-14.

Smits-Engelsman BCM, Niemeijer AS, Schoemaker MM. (1999). Dysgrafie of motorsiche schrijfproblemen bij kinderen. In: Aufdemkapme et al. (Eds). Jaarboek Fysiotherapie Kinesitherapie 2000, Houten: Bohn Staflue Van Loghum, p. 138-157.

Smits-Engelsman BCM, Schoemaker MM, Jansen MPHT, Niemeijer AS. (1996). Fysiotherapie bij schrijfproblemen. Een effectevaluatie. Nederlands Tijdschrift voor Fysiotherapie, 106: 156-166.

Het promotieonderzoek is gepresenteerd tijdens de volgende congressen: Internationaal Congres NVFK. The Netherlands. Veldhoven, 2003. The Clumsy Child; aetiology, pathogenesis and treatment. Groningen, 2002. Children with Coordination Difficulties. How parents, teachers and therapists can help

(clinical day DCD-V Conference). Canada, Alberta, Banff, 2002. DCD-V Developmental Coordination Disorder: mechanisms, measurement, and

management. 5th biennial workshop on children with a Developmental Coordination Disorder. Canada, Alberta, Banff, 2002.

"Towards a Society for All" - through Adapted Physical Activity. 13th international symposium AFAPA, Vienna, 2001.

3e Studentendag Bewegingswetenschappen, Amsterdam, 2000 DCD-IV Developmental Coordination Disorder, from research to diagnostics and

intervention. 4th biennial workshop on children with a Developmental Coordination Disorder, Groningen, 1999.



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15- Niemeijer - chapter 12 NCH

Northern Center for

Healthcare Research (NCH)


15- Niemeijer - chapter 12 NCH

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Northern Center for Healthcare Research (NCH) This thesis is published within the Northern Center for Healthcare Research (NCH) (embedded in the University Medical Center Groningen / University of Groningen). More information regarding the institute and its research can be obtained from our internetsite: www.med.rug.nl/nch.

Previous dissertations: Sturm HB (2007) Influencing physician prescribing in an international context: the role of systems, policies and patients. PROMOTORES: prof dr FM Haaijer-Ruskamp, prof dr WH van Gilst Akker-Scheek I van den (2007) Recovery after short-stay total hip and knee arthroplasty; evaluation of a support program and outcome determination. PROMOTORES: prof dr JW Groothoff, prof dr SK Bulstra COPROMOTORES: dr M Stevens, dr W Zijlstra

Visser A (2007) Children’s functioning following parental cancer. PROMOTORES: prof dr HJ Hoekstra, prof dr WTA van der Graaf COPROMOTOR: dr JEHM Hoekstra-Weebers Mei S van der (2007) Social participation after kidney transplantation. PROMOTORES: prof dr WJA van den Heuvel, prof dr JW Groothoff, prof dr PE de Jong COPROMOTOR: dr WJ van Son Greving J (2007) Trends in cardiovascular drug prescribing in Dutch general practice: role of patient and physician related characteristics. PROMOTORES: prof dr FM Haaijer-Ruskamp, prof dr D de Zeeuw COPROMOTOR: dr P Denig Khan MM (2007) Health policy analysis: the case of Pakistan. PROMOTORES: prof dr WJA van den Heuvel, prof dr JW Groothoff COPROMOTOR: dr JP van Dijk Huizinga GA (2006) The impact of parental cancer on children. PROMOTOR: prof dr HJ Hoekstra COPROMOTORES: dr JEHM Hoekstra-Weebers, dr WTA van der Graaf Dobre D (2006) Treatment of heart failure and patient outcomes in real life.

PROMOTORES: prof dr FM Haaijer-Ruskamp, prof dr R Sanderman, prof dr DJ van Veldhuisen

COPROMOTORES: dr AV Ranchor, dr MLJ de Jongste Rosenberger J (2006) Perceived health status after kidney transplantation. PROMOTORES: prof dr JW Groothoff, prof dr WJA van den Heuvel COPROMOTORES: dr JP van Dijk, dr R Roland Šléškova M (2006) Unemployment and the health of Slovak adolescents. PROMOTORES: prof dr SA Reijneveld, prof dr JW Groothoff COPROMOTORES: dr JP van Dijk, dr A Madarasova-Geckova

university of groningen neuromotor task training niemeijer ... · and ‘neuromotor task...

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