S50 ESMAC 2012 abstract / Gait & Posture 38 (2013) S1–S116

Fig. 1.

not described. The aim of this study was to describe standing pos-ture in relation to joint restrictions in children with bilateral CP.

Patients/materials and methods: Standing posture in 26 chil-dren with CP, mean age 11y (SD 3y), and 19 typically developingchildren, was recorded for 30 s with 3D motion analysis. Fifteenchildren with ability to stand without support were designatedCP-Group A (GMFCS I-III), and 11 who needed support for stand-ing CP-Group B (GMFCS III-IV). All children were tested with theirhabitual footwear. Passive joint range of motion (ROM) was mea-sured with a goniometer. Lower limb contractures were defined aspassive ROM less than neutral joint position.

Results: Uni- or bilateral joint contractures were equally pre-sented among the children in both CP groups A and B; in the hip(4 vs 7), the knee (6 vs 9), and in the ankle (2 vs 3). CP-Group Bpresented with significantly less passive joint ROM than CP- GroupA in hip extension (−4◦(SD 5◦) vs 1◦(SD 5◦), p = 0.022), knee exten-sion (−12◦(SD 10◦) vs 0◦(SD 6◦), p ≤ 0.001), and ankle dorsiflexion(2◦(SD 13◦) vs 7◦(SD 7◦), p = 0.009) (Fig. 1).

Children in both CP groups A and B stood with significantly moreflexion than their passive joint ROM in the hip (p ≤ 0.001 vs p = 0.004respectively), in the knee (p = 0.003 vs p = 0.003), and in the anklein CP Group A (p = 0.012 vs p = 0.182) (Fig. 1).

Discussion and conclusions: The flexed joint position duringstanding with respect to the passive joint extension ROM in bothCP groups indicates that the children did not utilize their possiblejoint extension ROM during upright standing. Knee flexor spasticitywas observed in both groups and might have contributed to diffi-culties to erect their lower limbs. The large difference between thejoint position in the unloaded and the upright positions, in partic-ular in the children who needed support (CP- Group B), might alsobe interpreted as lower limb muscle weakness. Which factors con-tribute to the difficulties to align the body segments and maintaina stable body position with respect to gravity during standing inchildren with bilateral CP requires further exploration.

References

[1] Woollacott and Crenna 2008.[2] Kerr et al., 2003.[3] Rosenbaum et al., 2007.

http://dx.doi.org/10.1016/j.gaitpost.2013.07.097

O84

Postural control and isometric strength of legextensor muscle in moderately physically activeyoung and elderly men

Helena Gapeyeva 1, Jaan Ereline 1, Tatjana Kums 1,Herje Aibast 1, Tauno Koovit 1, Siret Põldur 1, EnnSeppet 2, Mati Pääsuke 1

1 University of Tartu, Institute of Exercise Biologyand Physiotherapy, Tartu, Estonia2 University of Tartu, Department of General andMolecular Pathology, Tartu, Estonia

Introduction: The mechanisms contributing to age-relatedincrease in postural sway and falls in the elderly remain unclear.Quantitative loss of muscle mass or sarcopenia is the most impor-tant factor underlying the decline in muscle strength with aging [1].The aim of the present study was to compare postural control andisometric strength of leg extensor muscle characteristics betweenmoderately physically active young and elderly men.

Patients/materials and methods: Fifty-two healthy moder-ately physically active men participated in the study: 17 young menaged 21–26 years and 35 elderly men aged 67–86 years. The elderlymen were distributed into two groups – more physically active(MA) and less physically active (LA), based on a physical activityquestionnaire for the elderly [2]. Postural steadiness during 30 smonopedal standing (eyes open and eyes closed) was estimatedby centre of pressure (CoP) sway characteristics using force plate(Kistler, Switzerland) and Sway software (BTS S.p.A, Italy). Strengthof knee and leg extensors muscles’ isometric maximal voluntarycontraction (MVC) was measured with a custom-made isometricknee extensor bench and leg bench. Peak torque (PT) of MVC ofknee extensor muscle (KE) and of unilateral and bilateral MVC ofleg extensor muscle (LE) were measured. Ratios of PT to body mass(PT:BM) were calculated.

Results: Elderly MA and LA men had significantly lower PT:BMratio (p < 0.001) of KE muscle as well as unilateral and bilateralLE muscle as compared to younger men. Greater PT:BM ratio ofbilateral MVC strength of LE muscles (p < 0.05) was found in MAelderly as compared to LA. Larger CoP sway range in anteroposte-rior and mediolateral direction, longer CoP radius and faster CoPvelocity and greater mean sway area were noted in both groupsof elderly men (p < 0.05) as compared to younger men in eyesopen test. Analogous differences between groups were observedin eyes closed test for measured postural stability characteristics.Tendency of CoP sway radius to decrease by 22% and area by 21%was noted in MA ederly men as compared to LA in eyes open test,while no significant difference in these characteristics was foundbetween two elderly men’s groups.

Discussion and conclusions: Present study demonstrated (1)that elderly men had age-related deterioration of postural controlas compared to younger men; (2) tendency of improvement ofpostural steadiness in MA ederly men as compared to LA men.It was shown that elderly men with history of falls had largerCoP sway range in mediolateral direction and mean sway area ascompared to non-fallers [3]. Subjects of this study were moder-ately physically active and MA elderly men had greater bilateralisometric maximal strength generation of leg extensor muscleas compared to LA men. Recent study found neg ative relationbetween muscle volume of plantar flexors and postural sway inboth young and elderly adults [4].

Acknowledgement

This study was partly supported by the EC FP7 project GA-223576.

ESMAC 2012 abstract / Gait & Posture 38 (2013) S1–S116 S51

References

[1] Roubenoff R. Canadian Journal of Applied Physiology 2001;26:78–9.[2] Voorrips LE, et al. Medicine and Science in Sports and Exercise 1991;23:974–9.[3] Melzer I, Kurz I, Oddsson LI. Clinical Biomechanics (Bristol, Avon)

2010;25:984–8.[4] Kouzaki M, Masani K. Gait and Posture 2012;35:11–7.

http://dx.doi.org/10.1016/j.gaitpost.2013.07.098

O85

Core and lower extremity muscle recruitmentpattern in response to an unexpected externalperturbation in patients with patellofemoralpain syndrome and healthy individuals

Mana Biabanimoghaddam, Zahra Rojhani shirazi,Alireza Motealleh

Shiraz University of Medical Sciences, PhysicalTherapy Department, Shiraz, Iran

Introduction: Functions are generally developed through thekinetic chain and require the efficient subsequence in muscles acti-vation [1]. Deficit in neuromuscular control may be a contributingfactor to the development of musculoskeletal disorders such aspatellofemoral pain syndrome (pfps), which is a common and clini-cally complicated condition [2,3]. The aim of the present study wasto compare the electromyographic firing pattern of the core andlower extremity muscles in response to sudden lateral perturbationin patients with pfps and healthy subjects.

Patients/materials and methods: 27 females with pfp and 27healthy controls with no history of knee injuries participated inthis interventional study. Subjects were instrumented with EMGelectrodes on the erector spine, transverse abdominis and internaloblique, gluteus medius, tensor fascia lata, vastus lateralis, vastusmedialis obliqus and peroneus longus. Onsets of electromyographicactivation of the selected muscles were measured by surface EMG,ME6000 16-channel system(Kistler Ltd.Finland) in response toan unexpected mediolateral pelvic perturbation in standing posi-tion. Independent t-test was used to compare each muscle’s meanonset latency between groups. The muscle activation pattern ineach group was analyzed by a non- parametric friedman test andwilcoxon signed ranks test.

Results: Females with patellofemoral pain syndrome demon-strated delayed onset of gluteus medius (p = 0.025), vastus medialisobliqus(p = 0.033) and vastus lateralis(p = 0.024) and earlier acti-vation of internal oblique and transverse abdominis(p < 0.001)and also erector spine (p = 0.001), than the control group. Themuscles indicated significantly different activation time withingroups(p < 0.001).

Discussion and conclusions: This study provides evidence thatneuromuscular control and muscle activation pattern are differ-ent between individuals with pfps and healthy subjects. It appearsthat evaluating the entire kinetic chain rather than focusing on theaction of a particular segment is necessary to identify the compen-satory strategies of control system.

References

[1] Kibler Wb, et al. Sports Medicine 2008;36(3), 189- 98.[2] Fagan V, et al. British Journal of Sports Medicine 2008;42(10):789.[3] Bolgla La, et al. Journal of Electromyography and Kinesiology 2010;20(1), 142-

7.

http://dx.doi.org/10.1016/j.gaitpost.2013.07.099

O86

A new therapeutic target in equinus: Botulinumtoxin injection (Dysport®) in peroneus longus

Christophe Boulay, Michel Jacquemier, VincentPomero, Yann Glard, Elisabeth Castanier,Guillaume Authier, Gérard Bollini, BrigitteChabrol, Jean-Luc Jouve, Elke Viehweger

CHU Timone enfants, Aix-Marseille Univ, Gait lab,Pediatric Department, Marseille, France

Introduction: In young hemiplegic children (<6 years) an over-activity with abnormal timing EMG of Peroneus Longus (PL) isdescribed in dynamic equinus with hindfoot valgus by Boulay et al.[1]. This study would suggest that the PL could be a new therapeu-tic target: the treatment of PL by Botulinum Toxin injections wouldbe able to prevent onset of joint deformity (pes plano valgus andmid foot break). This hypothesis is tested in a retrospective study.The clinical and radiological efficiency of the Botulinum toxin in PLis assessed.

Patients/materials and methods: Sixteen hemiplegic CP chil-dren GMFCS 1 (3.25 yrs ± 1.5) with abnormal timing EMG of PLand dynamic equinus with hindfoot valgus [1] were treated by abotulinum toxin injection (Dysport®, Ipsen) only in PL (between6 and 7 ui/kg). Goniometric assessment of ankle passive dor-siflexion and foot morphology in a standing position had beencollected. Radiological foot parameters measured forefoot prona-tion (metatarsal stacking angle), midfoot planus (lateral talo-firstmetatarsal or Meary angle) and equinovalgus hind foot (Meary inci-dence of postero-anterior ankle, calcaneal pitch and talocalcanealangles) [2,3]. The intra and extra-observers variability are assessedand compared with those of the literature [2,3]. These parametersare validated in the healthy and hemiplegic children [2,3]. A pairedT-test compared for each angle the pre and post-toxin measure-ment.

Results: The ankle passive dorsiflexion was 13◦ ± 12◦ (pre-toxin) vs 12◦ ± 10◦ (post-toxin) (p<0.05). The parameters variabilitywas < 3◦. The parameters described between pre-toxin vs normaldata (2, 3): calcaneal pitch angle (7.6◦ vs 17◦ p < 0.001), talocal-caneal angle (54.8◦ vs 49◦ p < 0.05), lateral talo-first metatarsalangle (28.7◦ vs 13◦ p < 0.001) and metatarsal stacking angle (1.9◦ vs8◦ p < 0.001). There was a non-significative difference, between prevs post-toxin, for the calcaneal pitch angle (7.6◦ vs 9◦ p < 0.05) andthe postero-anterior ankle angle (14.2◦ vs 14.7◦ p < 0.05). There wasa significative difference, between pre vs post-toxin, for the talocal-caneal angle (54.8◦ vs 46◦ p < 0.001), the lateral talo-first metatarsalangle (28.7◦ vs 17.7◦ p < 0.01) and the metatarsal stacking angle(1.9◦ vs 7.2◦ p < 0.001).

Discussion and conclusions: There was no triceps surae con-tracture. The toxin injections were safety and did not provoke atalus. There was a clinical improvement on hind, mid and fore-foot. Before toxin injections vs normative data, the radios showed ahindfoot valgus with midfoot planus and a forefoot pronation. Aftertoxin injections, in correlation with clinic and the literature [2,3], X-rays described a significative decrease of hindfoot valgus and mid-foot planus and an absence of forefoot pronation. Botulinum toxinin PL had therapeutic actions on fore and midfoot and on the talus(hindfoot); there was no modification on the calcaneus. Thus PLcould be a new therapeutic target for Botulinum Toxin in pes planovalgus and mid foot break in young CP children before the onset ofmidfoot break deformity. Prospective study had to confirm thesedata in a large population.