servane mason,€¦ · a new anklefoot orthosis to correct footdrop servane mason a thesis...
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AN ASSESSMENT OF TOEOFF:
A NEW ANKLEFOOT ORTHOSIS TO CORRECT FOOTDROP
SERVANE MASON
A thesis submitted to the School of Rehabilitation Therapy
in conformity with the requirements for
the degree of Master of Science
Queen's University
Kingston, Ontario, Canada
July, 1999
copyright 0 Servane Mason, 1999
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ABSTRACT
The toeoff ankle-foot orthosis ( S O ) is a new device that was designed to absorb energy during
stance phase and to release it during push-og thereby conserving energy for the user- The purpose ofthis
research was to evaluate the & i of T e when compared to original AFOs. In a
pre-post intervention research design, 11 individuals already wearing AFOs trZaled the ToeOfforth~sis~
Effectiveness was evaluated by a continuum of tests which ranged fiom traditional quautitative techniques
for evaluating AFOs, to qualitative methods for soliciting user feedback. This combination of methods
looked at both user output or perfotmance and user input or satisfaction, In terms of user output, gait
anaiysis was used to assess whether ToeOBlindeed provided a power advantage during push1oE
Furthermore, walking tests and a log of daily activity levels were used to determine whether T o e
resulted in energy savings for its users, dwing timed walking tests and daily activities respectively. In
terms of user input, comparative and noncomparathe rating forms were used to w~kly assess user
satisfaction with the two orthoses on each of nine dimensions- Furthermore, focus groups wete conducted
to solicit user feedback and recommendations, providing data fiom individual contex-ts in respondents'
own words. Finally, a clinical assessment allowed determination of probable contraindicators to success
with ToeOE With a sample size of only I I participants, the statistical evidence that participants
performed better with T o e is limited, However, where statisticid significance was achieved, an
advantage of ToeOff was indicated- Looking at the absolute number of participants who achieved positive
or negative results, the majority of participants achieved positive results with To-, both in the
laboratory and during daily activities, as weU as indicating overall preference for this new orthosis,
Results of the ciinicai assessment suggest that adequate hip extension and ankle dorsiflexion range of
motion, along with sufficient knee extensor and hip flexor muscle strength, may be important for users to
achieve success with Toeoff. The ToeOff AFO is a valid alternative to the thermoplastic hinged AFO for
the correction of footdrop, As with any assistive device, its appropriateness should continue to be assessed
on an individual basis; results of this study should assist clinicians in determining whether ToeOff is
appropriate for their clients.
ACKNOWLEDGEMENTS
Many people's contn'butions to this resear& need to be acknowledged Thankyou to my cosupervison,
Tanya and Dr-Olney, for your guidance, encouragement and help11 f d a c k throughout tbis research;
working together has been an enjoyable experienoe, A big thankyou to the sixteen participants who
brought this research to We, many of whom travelled long distances to be part ofthe study- Thanks to
Rob and Chris in the Prosthetics and Orthotics Clinic at StMiuy's of the Lake Hospital, for a wonderfid
job fitting the ToeOfforthosis, aad making individual a d l n t s as necessary- For assistance coUectlng
the gait analysis data and understanding the instnunentation, thanks to Ian McBride- For interesting
discussions about the implications of small sample size, thanks to my advisory committee member Dr-
Smith. Thanks to Cally Martin for helping to define the clinical assessment measures, and to all the
physiotherapists at St Mary's of the Lake who helped to recruit participants- For performing all clinical
assessments, thanks to Alice Aiken Thanks to Camp Scandinavia, AB and Ttulife Inc, Camp Healthcare
Division, for providing the hciing and orthoses which made this research poss~ile. For a wonderfid job
which provided needed financial assistance during my i inal year, thanks to the department of women
studies. The thoughtful flowers a week before my defense were panicul& appreciated A final thankyou
to friends and family who supported me in this endeavour, particularly Dennis and my graduate
classmates, and helped me to celebrate afterwards-
Table of Contents
2-1 D O N S ................................................................................................. ............... 5
2.2 STROKE .................... ,....-. ............................................................................................................ 6
22.1 Demographics ................................................................................................................... 6
..................................................... 2.2.2 Impaimtent. Disability and Handicap Following Stroke 7
.............................................................................................................. 2.3 ASSI~~~ETECHNOLDGY 8
.................................................................................... 2.3.1 OtiIization of Amstive Technology 8
23.2 Quality of Life ................................................................................................................. I I
2.3.3 Evaiuation ofAm3tive Technology ................................................................................. 12
2.4 AMCLE-FOOT~RTHOSES ....................................................................................................... 15
.................................................................................. 2.4. I Utdization ofAnkle-Foot Orthoses 15
.................................................................................. 2.4.2 Evaluation ofAnkle Foot Orthoses 18
2.4.2.1 Gait Analysis ............. ,-..... ........................................................................................................ 18
2-4-23 Energy Expenditure ..................................................................................................................... 20
2-4-2-3 Walking Tests ............................................................................................................................. 21
2.4.2.4 Questionnaires ............................................................................................................................. 22
2.4.2.5 Focus Groups .............................................................................................................................. 23
............. ..*................................-...............................*............... 3.3. I Physiological Cost Index ,, 28
3-32 Six-Minute Walking Test*.. ................. .-............ ........ ....................................... 29
............................................................................................................................ 3 -6 Focus GROUPS 31
3- 7.1 Range ofMotion .............. .-. -......... ............................................................................... 32
................................................................................................................. 3- 7.2 Muscle S~ength 3 3
. . 3 7 S p t c . . ..................................................................................................................... 35
..................................................................................................... 3.7.4 Other Chical Measures 37
3.8 DATA ANALYSIS ........................................................................................................ 3 7
CHAPTER 1 . RESULTS ............ ....................... .................... ............... " ............. 40
.............................................................................................................................. 4.1 PARTICIPANTS 40
........................................................................................................................... 4.2 GAIT ANALYSIS 42
.................................................................................................. 42.1 Summary of Case Stucij # I 42
4 - 2 2 Sunrniary of Case Studj #2 .................................................................................................. 45
..................................... .................................................................................. 1.3 WALKING TESTS ... 49
..................................................................................................... 4.3. I Physiological Cost Index 49
........................................................... 4.3.1.1 PC1 Results at Self-Selected Comfortable W m Speeds 49
....................................................................... 4.3.1.2 PC1 Results at Self-Selected Fast Walking Speeds 51
.............................................................................................................. 4.3. 1.3 Summary of PC1 Results 52
4.3.3 Sumnrary of Walking Test Results ........................................................................................ 55
4.4 A c n v n v R ~ c o ~ ~ ..................................................................................................................... 5 5
..................................................................................................... 4.5 QUESTIONNAIRES 6 0
.............................. 4 5. I Noncompmative Rating Scales ... 6 0
................................................................................................. 4.5.2 Comparative Rating &aIe S. 61
4.6 Focus GROUPS ...............,................................... ........................................................................ 62
4.6.1 Social Context ........................................................................................................... 6 3
4-62 Fmction .. ........................................................-......................................... ......................... 65
4.6.3 Comfort ............................................................................................................................... 69
4 Appearance ......................................................................................................................... 70
. . 4 - 6 3 Applrcanon .......................................................................................................................... 72
46.6 User Recontmendations ....................................................................................................... 74
4-7 CLINICAL ASSESSMENT ..... ...............AL................ALAL................................................... ..... 74
4.7.1 Range ofMotion ........... ,,,, .............. .-. .................................................................................. 75
4- 7-2 Muscle Strength .......................~....~...................................................................................... 77
* 4- 7-3 spasrct ty. ............................................................................................................................ 79
.......................................................................................... 4- 7- 3 Other Clinical Measures 8 0
5.1 POWER GENERATION AT THE ............................................................................................. 82
5.2 ENERGY COST OF WALKING ......................................................................................................... 83
................................................ 5.2.1 Conrparison with Normal P U and Six-Minute Walk Results 84
5.3 PARTICIPATION IN DAILY ACTMTXES .................~..~~~~~.~.~.... ....-. . 86
5.3.1 Conrparison with Nomrut Time Use Vatues ................... .....--.. ............................................... 88
............................................................................................................................. 5.4 USER RATMGS 89
....................................................................................... 5.5 USER THOUGHTS AND IDEAS ............ ..,,.. 91
Appearance ................................................................................................................................... 92
Conflort.. ................................... ,, ................................................................................................ 92
..........................*.. ............................................................... Function .., 93
Application ................... ,,, .......................................................................................................... 95
User Recommendations... ..................... ..,.,. .................................... 9 5
5.6 ~ D I c A ~ ~ N s AND CONTRAINDICATIONS FOR TOEOFF ......................... .-.. .. %
................................ 5-6- 1 Range ofMotion . . 96
5.6.1. 1 ComparFson with Nonnal Range of Motion -. .............. -..................- ...................... 9 7
. 56-12 Summary of Range of Motion ..................... ...-....... ............................................... ..-.. 97
5.6.2 Muscle Strength ................................................................................................................... 98
5- 6- 2- 1 Comparison with Norma1 Mmck Strength ........... ,,. ........................................................... 99
......................................................................... 5.6.2.2 Summary of&fu.de Strength Findings I00
. . 5.6.3 Spasncz ty. ....... .........................................-........................................................................ 100
5-64 Other ClinicaZ Measures ................................................................................................... 101
5.6.5 Sunrmary of Indications and Contraindicatio~~~fir ToeOff ................................................ 101
CHAPTER 6. CONCLUSIONS AND RECOMMENDATIONS .............. .............. .................-. . 105
6.1 CONCLUSIO~S ............................................................................................................................ 105
6.2 LB.I~ATIONS OF THE STUDY ....................................................................................................... 107
6.3 S U G G ~ O N S FOR FURTHER RESEARCH ...................................................................................... 109
REFERENCES ............................................................................................................... 110
APPENDIX A.
APPENDIX B .
APPENDM C .
APPENDIX D .
AFO PI-S ........................ ........ .......-.......................... .......................... 120
CONSENT FORM ............,...... . ........"...-. " ..--....,UI.... .. 123
SUBJECT INFORMATION FORM .......................... .... ........................ .. .............. 126
CLINICAL ASSESSMENT FORM ............... ....................................................... 129
.................. APPENDIX E . ACTRE INSTRUCTION AND DATA COLLECTION FORMS ..--.. 132
.................... APPENDIX F. NONCOMPARATWE AND COMPARATIVE RATING SCALES 135
APPENDIX G . FOCUS GROUP INTERVIEW GUIDE. ......,.... ................................................... 137
APPENDM. E SUMMARY OF NORMAL POWER PROFEES D m GAIT-nnnn--- 140
L 1 Temporal and Distance Mkames .......................................................... - .....-............. ... ........ . 141
L2 Kinematic Variables. ......... .. ..........- ....................................... . . ......................................... 142
Joint Angle Rofrles ............................................................................... .......... . . . .... . . 142
L3 Moments -. ............................ . ........................... ............................... - ......................................... 145
Joint Moment Profiles ..................-. .... ....................................................................................... . 146
I-4 Powers ........................................-..-...................-.............-.....-.......-........................................... 149
Joint Power Profiles ...............................-......................................................--........... .................... 149
L5 Work ..................................................................................................................................... . . 153
APPENDIX J . GAIT ANALYSIS CASE STUDY #2 ., .. ...... ............. ..................mw. 1%
........................................................................... J- 1 Temporal and Distance Measnres ................... ,. .- . I%
........................................................................................................................ J-2 Kinematic Variables 155
Joint AngIe Profiles ................ .. ......................................................................................................... 155
................... J-3 Moments .--... ..................... ..................................................................................... 158
................................................................................ Joint Moment ProfiIes ...................................... 158
J.3 Powers ............................................................................................................................................. 162
Joint Power Profiles .................................................................... .t., ......................... ,...... .................. 162
............................................................................................................................................... J.5 Work 165
APPENDM K. REFERENCE VALUES FOR CLINICAL ASSESSMENT MEASURES ..........., 167
List of Tables
TABLE 3.1 MODIFIED ASHWORTH SCALE; .......... ....TH.TH.............................................. ............................... 35
...................... ...........................................*.....*............... TABLE 4.1 DESCR~ION OF PARTICIPANTS ,... 4 1
................................. TABLE 4.2 PEAK POWERS (W/KG) OFTHE ANKLE, KNEE AND HIP JOINTS FOR sl ..., 45
.................................... TABLE 4.3 PEAK POWERS (W/KG) OF THE ANKLE, KNEE AND HlI? JOINTS FOR S 16 48
................................................. TABLE 4.4 WORK (J/KG) ATTHE h M E , KNEE, AM) EfIP JOENlS F O R S ~ ~ 48
TAE~LE 4-12 PC1 AT SELF-SELECTED COMFORTABLE WWG SPEEDS ................................................... 50
................................................................... T ~ L E 4.13 PC1 AT SELF-SELECTED FAST WALKING SPEEDS 50
T~13~4.14 SIX~MINUTF, WALICUUGTESTRESULTS ...................................... .. .......................................... 54
................... TABLE 4.16 MEAN PERCENTAGE OF TUlE SPENT IN SLEEP, REST, AND PHYSICAL A C T ~ V ~ ~ Y ,., 57
................. TABLE 1.17 MLw PERCENTAGE OF WAKING TIME SPENT IN PAIN- FATIGUE & WEARING AFO 57
....................................... TAEKE 4.18 NONCOM PARA^ RATINGS OF ORIGINAL AND TOEOFF ORTHOSES 60
............................................. TABLE 4.19 COMPARATIVE RATINGS OF ORIGINAL AND TOEOFF ORTHOSES 62
................ TA~LE 4.20 USER RECOMMENDATIONS FOR IDEAL, ORIGINAL AND TOEOFF AFO ...,-.,..... .......... 74
TABLE 4.21 ACTIVE RANGE OFMOTION (DEGREES) OFTHE AITECED ANKLE, AND HIP .................. 76
TABLE 4.22 PASSIVE RANGE OF MOTION (DEGREES) OFTHE AFFECTED ANKLE, ME AND HIP ................. 77
T-LE 4.23 MUSCLE STRENGTH (KG FORCE) OF THE AFFECTED ANKLE, KNEE AND HC'E' ............................ 78
TABLE 4.24 MODIFIED ASHWORTH SCALE RATINGS OF PLANTARFLEXOR SPASTICITY ............................... 79
................................................................................................... TABLE 4.25 PENDULUM TEST RESULTS 80
TABLE 4.26 ANKLE ST.- m AND SOMATOSENSORY TESTING ............................................................... 81
........................................... TAEU 5.1. INDICATIONS AND CONTRAINDICATIONS FOR THE TOEOFF AFO 104
TABLERI . SUMMARYOFPOWERBURSTSD~GNORMALG~ ......................................................... 140
..................................... TABLE I . 1 MEAN OF THE TEMPORAL AND DISTANCE MEASURES OF GAIT FOR S 1 1 4 1
TABLE L2 RELATIVE ANGLES OF THE ANKLE, KNEE AND HIP JOINT (DEGREES) FORSL ........................... 142
TABLE 1.3 PEAK MOMENTS (NWKG) OF THE &WE, AND HIP JOINTS FOR S 1 ................................ 146
TABLE r.4 PEAK POWERS (W/KG) OF THE ANKLE, KNEE AND EXIP JOINTS FOR S f .................... ,. ............ 149
TASE Ls WORK(J/KG) ATTHE ANKLE, KNEE, AND HIP J o ~ FORSL ..........--..................................... 153
TABLEJ.~ ~ o F T H E T E M P O R A L ; \ N D D ~ A N C E ~ O F G ~ F O R S ~ ~ . . . . . . . . . . . ........................ 154
T ~ L E 3.2 RELATIVE ANGLES OFTHE ANKLE, KNEE AND HIP JO~(DEGREES) FOR S16 ......................... 155
T-AELE J.3 PEAK MOMENTS (??WKG) OFTHE ANKLE, iCNEE AND HTP JOINTS FOR S16 .............................. 159
TABLE J.4 PEAECPOWERS ( W ~ G ) OFTHE ANKLE, KNEE AND HIP JOINTS F O R S ~ ~ ................................... 162
TABLE J.5 WORK (JAG) AT THE ANKLE, KNEE, AND HfP JOINTS FOR S 16 ............................................. I66
TABLE 1 . NORMAL AC=TNE &WGE OF MOTTON (DEGREES) OF THE ANKLE, WE AND .................. 167
TABLE K.2. NORMAL PA~SIVE RANGE OF MOTION (DEGREES) OF TE~E ANKLE, KNEE AND HLP .................. 167
TABLE IC3 . NORMAL MUSCLE STRENGTX (KG) OF THE ANKLE, KNEE AND E l P ....................................... 168
F1GURE4-1 J O ~ P O W E R PROFILES O F S ~ WHEN -G ORLGINAL AFO ................................... ,,........-. 43
.................................................. FIGURE 4.2 JoXNTPOWERPROFILES OF SI WHEN WEARING TOEOFF AFO 44
........ FIGURE 4-13 PHYSIOLOGICAL COST INDEX AT SELF-SELECTED COMFORTABLE WALKING SPEEDS .....- 53
FIGURE A 1. PICTURES OFTHERMOPLASTIC HINGED DROPFOOT A . 0 ................................................... 120
FIGURE A2. PICTURE$ OFTHERMOPLASTIC HINGED PLANTARFLEXION ASSIST AFO ......................... ........ 121
FIGURE A3. PI= OF TOEOFF AFO ............................................................................................... 122
FIGURE H 1- POWERS OFTHE HIP. KNEE AND ANKLE FOR 1 9 NORMAL ADULTS WALKING AT SLOW AND
........................................................................................................ NATURAL CADENCES 140
.............................................. FIGURE 1.1 JOINT ANGLE PROFILES OF S 1 WHEN WEARING ORIG ZNAL AFO 143
FIGURE l.2 JOINT ANGLE PROFILES OF S 1 WHEN WEARING TOEOFF AFO .................................. ..,.,,...... 144
FIGURE 1.3 JON MO~~ENT PRO- OF S 1 WHEN WEARING ORIGINAL A.FO ........................................ I47
FIGURE 1.4 JOM MOMENT PROFILES OF S 1 WHEN WEARING TOEOFF AFO ........................................ 148
FIGURE 1.5 JOINT POWER PROFILES OF S 1 WHEN WEiWNG ORIGINAL AFO .............................................. 150
FIGW 1.6 JOINT POWER PROFILES OF S I WHEN w m w ~ TOEOFF AFO .............................................. 1 5 1
FIGURE J . 1 JOW ANGLE PROFILES OF S 1 6 WHEN WEARING ORIGINGL AFO ....................................... 156
FIGURE J.2 JOINT ANGLE PROFILES OF S 16 WHEN WEAEUNG TOEOFF AFO .................... .,,... .................... 156
FIGURE J.3 JOINT MOMENT PROFILES OF S 16 WHEN WEARING ORIGINAL N o ....................................... 160
FIGURE J.4 JOINT MOMENTPROFILES OF S 1 6 WHEN WEARING TOEOFF AFO .......................................... 161
CHAPTER 1. Introduction
Mobility is a critical component of personal independence and participation in many activities-
For persons with locomotor disabilities, a Iack of mobility results in barriers to participation in daily
activities of selfcare, productivity, and Ieisure. One approach to reducing these barriers is the use of
assistivc technology, broadly defined as any device or piece of equipment that improves the Quality of Me
of a person with a disability. Assistive technology includes "any item, piece of equipment, or product
system, whether squired commem*alIy off the shelf; modified, or customized, that is used to increase,
maintain, or improve functional capabilities ofindividuaIs with disabiiities" flechnology Related
Assistance for Individuals with Disabilities Act, 1988), according to the internationally accepted
dehition of assistive technoiogy (Scherer, 19%)-
N o d walking patterns can be altered by neuromuscular and skeletal disorders such as
cerebrovascular accidents, peripheral neuropathy, postpolio sequelae and Charcott Marie Toothe disease
(Nawoczenski & Epier, 1997)- Orthoses that estend fiom the sole ofthe foot to just bdow the knee are
called ankle-foot orthoses (AFOs), AFOs may be pxescri- for persons with the above conditions with
aims such as improving their walking pattern, decreasing energy expenditure, stabiiizing and protecting
the ankle, or ensuring safe ambuIation. In general, the AFO serves to assist, control and rrclintain the
desired position of the anWc and foot during ambulation- While static orthoses immobilize, stabilize and
support joints in a desired position, dynamic orthoses generally perform a more complex fbm-oa
Dynamic orthoses permit movement of the involved joints, either by atlowing muscles to move the joint
while the orthosis controls the direction or alignment of movement, or by providing a substitute power
source for weak muscles. Several merent AFO designs are available; the materials and components
chosen are determined by the type of control or assistance desired at the ankle-foot complex (Leonard et
al., 1989).
The AFO commonly provided for the correction of fmtdrop is a custom-fabricated,
thermoplastic, hinged orthosis (see Figure A 1 in Appendix A). The orthosis is worn inside the shoe and
posterior to the calfl and attached to the leg with one or two velcm straps. The ToeOff N O is
prefabricated in thfee sizes, and made of a glass fiber, carbon fiber and Kevlar compound (see Figure A 3
in Appendix A). It is also worn inside the shoe bat the proximal portion covers the anterior pan of the
leg, bridging the ankle and pmemting plantarflexion. The absence of material at the back of the leg is
evpected to enhance codort by avoiding contact with sensitive areas such as the Achilles tendon, the heel
and the malleoli (Willner & Smits, 1998). The orthosis is thin, which should allow use in normal shoes
(Willner & Smits, 1998), is attached with velcro straps, and is lightweight, Lighter weight and the ability
to use orthoses in different shoes have previously been identified by users as positive am'butes (Krebs,
Edelstain, & Fishman, 1988).
A single case study compared gait measurements on a 3 5 year-old male with paralysis of the I&
medial triceps m e , when wearing a comentiona1 dropfoot AFO and when wearing ToeOff(Wiilner &
Smits, 1998)- This preIiminary study found that ToeOff slightIy increased velocity and stride length,
suggesting that ToeOff may improve walldng capacity- FurthermoreT single limb support time more
closely approximated that of the normal gait cycle when wearing TceOEas compared to a conventional
drop foot AFO- These positive results indicated a need for a more comprehensive assessment of the
T o e AFO that involved a greater number of users.
In designing or evaluating any new technology or product, the objective is to &tennine whether
this new technolog). appropriately meets its users' needs, The best way to make this determination is to
directly involve users in the evaluation process (Orpwood, 1990)- Research suggests that device
abandonment could be greatly reduced if consumers were actively involved in all stages of the design and
development processOCeSS According to consumerrbased evaluation theory, persons who have used a device
for an extended period of time are best quaIified to evaluate this dm-ce (Eatavia & Hammer, 1990)- To
evaluate the ToeOff AFO, the present study combines laboratory techniques traditionally used in the
evaluation of orthoses with measures of daily activity levels over two typical weekdays* as well as
soliciting user feedback and recommendations.
Purpose
The Teorthos is was desl-gned to absorb energy during stance phase and to release it during
push-oE conserving energy for the user by helping her to move forward The purpose of this tesearch
was to evaluate the &ectiveness of Toeoff; when compared to mcipants' original AFOs. EEiectiveness
was evaluated by looking at a continuum of tests which ranged from more traditional quantitative
techniques for evaiuating AFOs, to more rece~tly appreciated @tative methods for soliciting user
feedback This combination of methock looks, at user oatput or performance along with user input or
satisfaction, In terms of user output, gait analysis was used to assess whether ToeOff indeed p-dd a
power advantage during push-oE Furthermore, waking tests and a log of daily activity levels were used
to determine whether ToeOffresults in energy savings for its users, during rimed walking tests and daily
activities respectivelyY In terms of userinput, comparative and noncomparative rating forms were used to
quickiy assess user satisfaction with the two orthoses on each of nine dimensions, while focus groups were
conducted to solicit user feedback and recommendations, and provided data fiom individual contexts in
respondents' own words- Finally, a chical assessment provided data which allowed determination of
probable contraindicators to success with ToeOK
Research Hypotheses
When wearing ToeOff compared to their origiual AFO, it is e.vpected that:
Users will demonstrate a larger power burst at the affected ankle during push-off, as determined by
gait analysis.
Users will demonstrate evidence of lower energy e.\pendihue during ambulation, as determined by
wallcing tests and calculation of the physiological cost index (PCI).
Users will be more active andlor Iess Gtigued in a typical day, as determined by a daily Activity
Record (ActRe) completed over two consecutive weekdays with each orthosis.
Users will prefer ToeOff to their originaI AFO, as determined by comparative and noncomparative
ratings of the two orthoses.
Research Questions
What are the perceived advantages and disadvantages of weaning Toeoff compared to
original AFOs, and how could these orthoses be improved, as determined by experienced uses?
What are the cLinicai indicators and/or contraindicators for p--ption ofthe ToeOff AFO?
CHAPTER 2. Literature Review
2.1 Definitions 1
Deficits in arcas such as mob'ity, *on, heiuing, or communication, result in barriers to
participation in daily activities ofseIfkare, productivity, and leisure. Impairment tefers to any disturbance.
of a heahrelated intrinsic human system, such as the dishlrbance of anatomical m, physiological
or psychologid function (Schuntermann, 19%)- Disability is defined as any disturbance of an
individual's ability or skill, or in llfiliing their part in a role ( S c h u n e 19%). This includes a
restriction or Iack in ability, d t i n g from an impairmenf to perform an activity In the manner
considered normal for a human being (World Health Or~kat ion, 1980)- Handicap ders to the
disadvantage experienced as a result of impairment or disability (Bonita, 1992; Schuntermann, 19%).
One approach to reducing these barriers is the use of mstive technology, broadly defined as any
device or piece of equipment that improves the quality of life of a person with a disability. According to
the generally accepted definition of assistive technology internationalIy (Scherer, 1996), assistive
technology includes "any item, piece of eqyipment, or product system, whether acquired commem*aUy off
the shelf, modif~ed, or customized, that is used to increase, maintain, or improve hct ional capabilities of
individuals with disabilities" (T'echnoIogy Related Assistance for IndividuaIs with Disabilities Act, 1988)-
Footdrop refers to paresis or paralysis of the foot dotsiflexors- Stroke, trrain injury, incomplete
spinal cord injury, and peripheral neuropathies often result in dysriurction of the foot dorsiaexors
( L e h n n . Condon, de Lateur, & Price, 1986)- Inadequate dorsiflesion of the foot is the most common
type of motor loss exhiiited by stroke patients (McCoUough, 1978a; McColIough, 1978b). Many stroke
patients eshiiit footdrop as the only major gait abnormalityt while in other cases this is accompanied by
spastic equinus, knee hyperestension, or an unstable knee (McCoUou& 1978a)- In the case of peripheral
neuropathies, the most common cause of footdrop is damage to the common peroneal nerve. This
condition is relatively common among younger patients, in whom traumatic events occur more frequently
(Van Langenhove, PollefIiet, & Vanderstraeten, 1989).
2.2 Stroke
2.2.1 Demographics
CerebrovascuIar acciient (CVA), commonly referred to as stroke, is the third leading cause of
death within industnabzed . - nations @onit& 1992; Duncan, 1994), as well as the primary cause of
disability in the elderly ( H e m and Stroke Foundation of Ontario, 1994). An estimated 45,000 Canadians
are admitted to acute care facilities for the treatment of cerebrovascular disorders each year (Heart and
Stroke Foundation of Ontario, 1994)- The major risk factors for stroke inciude age, hypertension, cardiac
disease, diabetes rnellitus, and previous stroke or transient ischemic attack (Lorish, 1993; Warlow, 1998),
as well as cigarette smoking, alcohol consumption, use of oral contraceptives, physical inactivityf and
obesity (Marmot & Poulter, 1992; W e l d & W i i 1990; Warfow, 199%).
The World Health Organization defines stroke as "rapidly deweloping clinical signs of focal (or
global) disturbance of cerebral function, with symptoms lasting 24 hours or longer or leading to death,
with no apparent came other than of vascular origin" (WHO MOMCA Project, 1988). Stroke results
from either restricted blood supply to the brain (ischemia) or haemorrhage into the brain tissue, both of
which cause cell damage and impaired neurological fhnctr-on (Mayo, Korner-Bitenski, & Becker, 199 1)-
Approsimately 80 (Warlow, 1998) to 90 (O'sufivan, 1994) percent of ail strokes are ischaemic, while
the remaining percentage are haemorrbgic and tend to cause greater damage to the brain tissue (Mayo et
a/., 1991).
Since 1961, the age-adjusted stroke mortaIity rate in Canada has decIined by 57% and 65% in
women and men respectively. Today Canada has one of the Iowest stroke mortality rates among
industrialized countries, with a survivaI rate ofappro.ximately 82 percent and 85 percent for women and
men mpectively. This rate declines slightly with increasing age to 79 percent for women 75-84 a d to 67
percent for women greater than 85 (Petrasovits & Nair, 1994)- Individuals who swvive beyond 18-
months post-stroke have life expectancies comparable to those of the general age and sexmatched
population (Stineman & Granger, 199 1)- Although a majority of stroke survivors have disabilities, nearly
80 percent regain suff~cient lower extremity fimction to be ambulatory with or without the use of assistive
devices ( G r e s m Fitqatrick, & W o e 1975)- Approximatciy 40 percent of stroke SUCViVofs require
help with one or more am-t ies of daily living (Wade, 1992), while about a third of persons aIfve: 6
months post-stroke are dependent on others for activities of M y living (Warlow, 1998).
Due to the high prevalence of stroke, the growing number of elderly persons in the population,
and the high survivaI rate of individuaIs with tcsulting disabilities, the development and evaluation of
services to assist this population should be a priority. Appropriate assistive devices can improve the
functiond capabilities of stroke survivors, thereby increasing their participation in daily activities and
potentially improving their quality of We.
2.2.2 Impairment, Disability and Handicap Following Stroke
Clinical manifestations of stroke include impairments in motor and sensory systems, vision,
language, perception, cognitive function, and continence (O'Sullivan, 1994; Wiebers, Feigin, & Brown,
1997)- The seventy of these deficits is determined by the location and size of the brain lesion, as well as
the amount of collateral blood flow (O'Suflivan, 1994).
Impairments often testcia an individual's ability to participate in daily activities However, the
progression from impairment to disability to handicap is not always universal, sequential or unidirectional
(National Institutes of Health, 1993)- Rather, the relation of impairments to disability in stroke has been
shown to be complex, and to involve a range of factors including physical impairment (Sackley, 1991),
perceptual impairment (Mayo er a/-, 199 I), demographic characteristr-cs, motivation and depre&on C(u,
Guo, Chen, & Liang, 1993).
Disabilities limit participation in essential and rneaningfbl life roles, Residual disability
following stroke is difficult to due to the &ability of subject populations, timing of
assessments, and use of different measurement scales which make comparisons and generalization
difficult @ombovy3 199 1). The Framingham study found that up to 90% of stroke SUrYiVors had
disabilities, and that these disabilities included areas such as mobility dependence, dependence in
activities of daily living, reduced vocational hction, and decreased socialization outside the home
(Gresham et aL, 1975; Jette, Pinski, Branch, Wolf, & Feinleib* 1988). The recovery of walking function
is a primary goal of stroke survivors (Bohannon, Horton, & Wikholm, 1991)-
2.3 Assistive Technology
2.3.1 Utilization of Assistive Technology
Assistive technologies can be used to increase, mainmaintain, or improve the firaa*onal capabilities of
individuals with disabilities, thereby reducing disability and handicap. Our technology+riented society
increasingly views assistive devices as a means of improving the fiurctional independence and Quality of
life of individuals with disabilities (Rogers & H o b 1992)- However, although a direct relationship
benveen usage of assistive technology and quality of life is assumed, non-use does not prevent the
attainment of a high quaiity of life (Scherer, 1996). Individuals with similar disabilities may use Merent
assistive technoIogies, or choose to use no device at aU, Persons who are able to perform an activity
without using a device, even when it is more diflicuit or an alternate technique is required, tend to do so
(Haworth, 1983; Shipman, 1987)- The reasons for variable use of assistive technology have been
classified into three areas relating to cltaracteristics ofthe individual, the environment, and the technology
(Gitlin. Lwine, & Geiger, 1993; Scherer, 1996)-
Characteristics ofthe individual which influence usage of assistive technology include the
person's physical abilities, as well as personal preferences and values (Gitlin et a/,, 1993). Cultural and
ethic background have been identified as factors influencing the use or non-use of a range of
technologies (Barney, 199 1; McCormack, 1987; Zola, 1986). For an assistive technology to be &eCtive, it
must improve bctional capabilities within areas which are of concern to the user, responding to client-
identified goals and values. In a survey of 227 adults with a range of disabilities (PbilIips & Zhao, 1993),
the most important factor influencing device abandonment was a change in the needs or priorities of the
user. This included improvement or decline in medical condition and hctional abilities, as well as
changes in personal activities or goals, for example returning to work In general, usage rates for assistive
technology have not been adjusted to accommodate appropriate discard of devices due to improvement or
decline in abilities (Rogers & Holm, 1992)- Consumer expectations for e f f ' e n e s s , reliability?
durability, comfort, and ease of use are also directly related to device abandonment Phillips & Zhao,
1993). For esample. factors associated with the abandonment of hearing aids inciuded disappointment
that perfect hearing was not restored (Scherer & Frisina, 1994)-
Environmental characteristics that Influence usage ofasiaive technology include the physical
and social characteristics of the person's home and community (Gitlin et al., 1993). For example, the
physical dimensions of an individual's home may preclude the use ofcertain devices, such as wheelchairs,
unless these dimensions can be altered A study of 30 clients who had received one or more assistive
devices prior to discharge fmm hospitaI found that persons who had received a home visit were twice as
likely to use all of their prescri'bed equipment than those who bad not (Finlayson & Havkxbeck, 1992).
The availability of caregivers and other family members also influences device usage- In a study of
utilization of five self- devices by 50 persons discharged b m an acute rehabilitation setting, 77 of the
140 devices issued were never or rarely used four to six weeks after discharge. For 17% of the discarded
devices, the major reason for non-use was that it was easier to have someone else assist with the task
(Geiger, 1990)-
The finai category which influences utilization of assistive technology is the characteristics of the
technology itself, The ease of use of a device M y influences frequency of use- In the previously cited
study (Geiger, 1990), 12% of discarded devices were no longer in use because they were too cumbersome.
The usability, aesthetics. and reliability of many devices require improvement (Scherer, 1996), and may
contribute to device abandonment unless the device is indispensable, Note that the three categories of
factors influencing assistive device usage are interrelated- For esample, an individual who chooses not to
use a device because of its lack of aesthetic appeal is influenced by both fixtors of personal preference and
device characteristics.
Abandonment ofassistive technology after it has been obtained is related to the type of assistance
provided. On average, one-third of optional assistive devices are abandoned, usually within the first 3
months after prescription (Scherer & Galvin, 1991)- Two weeks after discharge, Haworth (1983) reported
that only 82% of toilet devices. 81% of walking devices, 74% of dressing devices, and 64% of bathing
devices were being used. In a survey of 227 adults with a range of disabilities, an overall device
abandonment rate of 29.3% was found In this study the majority ofabandoned dcviccs were mobility
aids, with an average abandonment rate of&% for canes, braces, or walkers (PW-ps &Zhao, 1993)-
A few studies have reported usage and satlsfam-on rates for orthoses, without specific reference to
ankle foot orthoses. A telephone survey of 100 ciients suppIied wit ' 11 1 new as&ive devices was
conducted after a 16-week follow-up period, and found that 26 of 3 L lower Iimb orthoses were still in use,
However, 5 of 3 1 individuals supplied lower limb orthoses were unsatisfied with their devices, which was
the highest dissatisfaction rate ofall categories. As a possl'ble explanation, the authors suggest that
user expeaations of improved ambulation after initiating use ofa lower I h b orthosis were perhaps too
optimistic (Caudrey & Seeger, 1983)- Similarly, a follow-up ofassistive technology usage by disabled
children found that 85% of 298 orthoses and prostheses were in use, and 82% were used dally- This
survey included all devices owned by the children; fiuther examination showed that 19 orthoses and
prostheses had been r e p l a d but not returned, while 7 were no longer needed. A fiuther 10 devices in
this category were now too small, leaving only 8 which were needed but not used (Korpela, Sepmen, &
Matti, 1993)- E-samining the utiiization of appropriate orthoses and prostheses only, 254 of 262 or 97%
of these devices were in use- Unfortunately this study does not state the elapsed time before followup,
which makes comparison with Caudrey and Seeger (1983) difficult Furthermore, this latter study was
performed by telephone, and did not assess whether devices were still required
Parker and Thorslund (199 1) looked at the assistive device usage of 57 persons over the age of 74
and living at home, The authors found that each person interviewed had at least one technical aid, and
that 73% of subjects had at least one device that granted autonomy. Within this randomly selected group
of individuals, 65% of 20 orthoses and prostheses were in use- More than half of the 422 dwices in all
categories were no longer in use because of a change in the owner's physical condition, however details on
the reasons for abandoment of orthoses and prostheses specifically were not given. Because participants
were seIected randomly, the elapsed time before follow-up wouId have been variable for each device in
this study, afthough this factor was not examined, Overall, one would expect a high usage rate shortly
after prescription., with rates declining over time as users' needs change.
Examination of factors contributing to device abandonment may elucidate situations in which
prescription is inappropriate, as well as suggest improvements to existing dmeYLces and to the device
selection process itself, In a follow-up study of aSSlStiVe usage by 30 persons p r e s c n i one or
more occupational therapy aids, comments and suggestions received fiom patients led to revisions of
equipment constructed within the department to improve quality and or selection of devices ( F i i s o n &
Havixbeck, 1992)- Device abandonment may be the result ofthe therapist not having done a
comprehensive needs assessment which involved the consumer, or not having provided adequate training
(Scadden, 199 1)- Consumer invoivement in device seiection has been associated with a reduction in
device abandonment (Phillips & Zhao, 1993)-
2.3.2 Quality of Life
The concept of quality of life involves dimensions of physical, psychological, bctional and
social health (de Haan, Aaronson, Limburg, & van CreveI, 1993). The positive effect of assistive
technologies on quality of life is generally taken for granted However, aIthough there is assumed to be a
direct relationship between usage of assistive technology and quality of life, non-use does not prwent the
attainment of a high quality of life (Scherer, 1996)- Rather, quality of life is directly related to the
dynamic integration of the individual into society (Dossa, 1989).
In a study of quality of life and assistive device usage in individuals with spinal cord injury or
cerebral palsy, participants' desire for social acceptance and integration emerged fiom serni-structured
intensive in te~ews. In seeking to achieve quality lives, participants did not focus on assistive
teclmologies, but saw these as either enlmcing or detracting from their acceptance and integration into
society- A user of communication equipment commented, "Now people want to talk to me," while a non-
user ehyIained, "I'm comfortable with [my Memowriter], but the person I'm trying to speak with finds
that it takes too long" (Scherer, 1988)-
Decisions regarding usage of assistive technologies are not made simply for functional or
utilitarian reasons, but based on the compliance of the devr-ce with personal lifesryles and roles. To test
this hypothesis, 23 elderly persons were asked to seIect one of the two items in 12 pairs of physical and
occupational therapy devices that were matched according to bctioa, Differences between male and
female selections suggest that both sexes chose items which easily conformed with their lifestyits and
current or former roles- For example, the men chose sports equipment to regain fiurdonal balance and
nuts and bolts to develop c o o ~ t i o n , while the women selected a balance board and coloured pegs
respectively (Small & Grose, 1993). Another example is cited in Small and Grose (1993), describing the
case of a woman who rejected a spork rocker M e , despite its utilitarian value, because she thought it
would draw unwanted attention when eating with If an individual considers a device to carry
tlnwanted symbolic meaning, suggesting, for exampie, dRriance fiom the norm, lack ofability* or
unattractiveness, any potential firnctional benefit may be overshadowed-
Persons who have suffered a stroke tend to report a decreased q d t y of life compared to their
premorbid conditioa; suoke survivors demonstrate significantly lower subjective well-being than control
subjects of similar age (Ahlsi6, Brittoq Murray, & Theorell, 1984; h 6 m , Asplund, & &m, 1992;
Ebrallim, Barer, & Nouri, 1986; Kitanen, Fugi-Meyer, Bemsphg, & Fugl-Meyer, 1988). Using the
Nottingham Health Profile to measure quality of lifeT Ebrahim er al, (1986) reported that of 198 stroke
sunrivors evaluated at 6 months post-stroke, scores relating to energy @=0-05), pain Q H . 0 1), emotion
(p=0.01) and isolation @=0.0001) were significantly worse for persons still unable to walk. This suggests
that enabling stroke patients' ability to walk, with or without the use of an assistive device, may greatly
benefit their quality of life- Furthermore, the recovery of walking function has been identified as a
primary goal of stroke survivors (Bohannon et al., 1991).
2.3.3 Evaluation of Assistive Technology
The objective of evaluating assistive technology is to determine the extent to which a device or
system meets the needs of users, along with the user population for wluch such technologies are most
appropriate. Levy Ci987) identified two distinct types of technology evaluation: technical waluation and
hctional evaluation, Technical evaluation involves technical laboratory testing and analysis of
mechanical, electrical and physical fktors, with the objective of evaluating technical function,
performance and safety using established teclmica1 standards. Functional evaluation involves the
application ofstandardiztd mefhodoIogies in a Iaboratory setting and aims to determine the etliectiveness
of a device or system in meeting the perceived need$ of USUS.
Neither of these evaluation techniques Illy addresses the question of whether user needs are
being met by the technology in question The technical evaluation, although important, can be performed
with little or no interaction with users, and even the fhctionaI evaluation typically does not involve the
users in any meaningfirl way, Users are asked to perform standardized tasks under controlled conditions,
but are not asked about the relevance of such tasks to their daily lives. Furfhemore, the laboratory setting
is indifferent to the context of individual lives, which means that Iaboratory results may not be
transfenable to real world activities-
The recent growth ofthe consumer movement in rehabilitation has led to increased awareness of
the many persons with disabilities who want to make informed decisions about which treatments and
sem*ces they receive. This has resulted in consumer pankipation at many levels of d-on-making,
whether making personal Veaunent decisions or lobbying the government for change- The recognition
that user input is important has served as the foundation for consumer-based evaluation theory. This
theory has two basic premises, that the consumer should be the ultimate evaluator of whether a device is
satisfactory, and that the consumer who has used a device for an extended period of time is most capable
of i d e n e n g factors to be considered in developing evaluation criteria for the device (Batavia & Hammer,
1990). To emure that assistive devices enhance users' quaIity of Life, consumers need to be involved in
the selection and evaluation of these dwices (Scherer, 1996)- It has been suggested that consultation with
end-users could significantly reduce device abandonment (Fisher, 199 1). The process of matching an
individual with an assistive device is comples, precisely because people's respbnses to technology are
complex A better understanding of the rationale behind individual decisions to accept or reject different
types of assistive technology is critical to improving the effectiveness of these interventions (Scheter,
1996).
Despite their first-hand experience, individuals with disabilities have generally not been irrvolved
in the research and development of new assisrive devices (Fisher, f 991)- Involving consumers at all
stages of the design and development process ensures that new assistive technologies are responsive to the
actual needs of users- Orpwood (1990) recommended that a t w o - p ~ ~ process be used in designing
technology for individuaIs with disabiIities. Standard design methudologies follow a Iincar path fiom
problem definition and compilation of design specifications to -cc deveIopment However, in the case
of assistive technologies many specifications are diflticult to define until the device is actually Wed by a
user, Orpwood's alternative design methodoiogy addresses the user interhce and the supporting technical
features of the assistive device independently. Potential consumers are involved fiom an early stage of
product development, participating in an iterative design process by testing and providing feedback on a
series of rough prototypes ofthe final d e v h Throu&out this pmscs, specification of the uses hterEace
evolves directIy Born user participation and feprlhack
The Orpwood methodology was recently applied to the design and development of a wheeled
mobility device for women with disabilities in Mia (Lysack, Wyss, Packer, Mulhollaad, & PanchaI,
1999). The participation of potential users was inmumental in determining their functional needs and
preferences (Mulholiand, Packer, Laschinger, Olaeyy & Panchal, 1998), fiom which design specifications
and working models were deveioped The international Whirlwind wheelchair project (HOE Hotchkiss, &
Pfaeizer. 1993) also involved consumers at ail stages of wvheelctrair design, development and distn'bution.
Consumer involvement in device selection and evaluation soficits perspectives that may otherwise go
unrecognized, A study by Pugh and Stansfield (1989) found that the drinking equipment most prescribed
by therapists was that most disliked by persons with arthn-tis because they felt insecure using it and
considered it unattractive. Furthermore, the cups most popular with these patients were the least known
and lean prescnid by therapists. Although suppliers of assistive technology are very responsive to the
physical needs of their consumers, there is frequently less attention given to the psychological and social
aspects of assistive device use (Scherer, 1996), aspects which will certainly &ace fiom consumer
participation.
Qualitative approaches are becoming recognized as a complement to existing quantitative
techniques for the evaluation of technology (Levy. L987; Scherer & Lane, 1997)- Levy (1987) identifies
reiiabiIity as the strength of quantitative techniques, and validity as the strength of qualitative methods-
Functional and laboratory testing are controlhbh and reproduceable, whereas individuai statements about
a particular technology's daily usefihess are meaningfur and relevant.
2.4 Ankle-Foot Orthoses
2.4.1 Utilization of Ankle-Foot Orthoses
Ankle fwt orthoscs (AFOs) are a fonn of assistive technology which can be phscnbed for
individuals with neuromuscular and skeletal disorders to improve walking patterns, decrease energy
espenditure, stabilize and protect the ankIe, and ensure safe ambuiation 1979; Leonard er of-,
1989). In general, the AFO semes to assist, control and maintain the desired position of the ankle and
foot during arnbulation, Used with basically ambulaiory cIients who &%it problems walking,
particularly footdrop and spastic equinm (Rubin & Cohen, 1988), the AFO aims to approximate the
biomechanics of normal ambulation as closely as posslile (Leonard et al-, 1989).
There are several Merent types of AFOs. which can be categorized according to function and
fabrication. While static orthoses immobilize, stabilize and support joints in a desired position, dynamic
orthoses generally perform a more comple-u function, Dynamic orthoses permit movement of the involved
joints, either by alIowing muscles to move the joint while the orthosis controls the direction or alignment
of movement, or by providing a substitute power source for weak muscles (Leonard et aL, 1989). Custom-
fabricated AFOs are made by the orthotist according to a specific design, but are fabricated fiom a positive
model of the leg and foot and thus molded specfically to the dimensions of the user. Prefabricated AFOs
are commercially available, usually in a selection of sizes, but may require individual adjustments during
the fitting process.
Early AFOs were constructed of metal and leather, and consisted of two metal ban attached
e-e-ml ly to a heavy shoe (Ofir & Sell, 1980)- Worn inside the shoe, the first plastic AFOs were
introduced in the late 1960's (lebsen, Simons, & Corcorau, 1968; Lehrnann, 1979; Simons, Jebsen, &
Wildman, 1967)' and their prescription increased as that of metal AFOs decreased- In a ten-year
retrospective study of orthoses and ambulation in hemiplegia, a decrease in the number of metal AFOs
was observed in 1970; by 1973 this type of otthosis was no longer prescribed by the Institute of
Rehabilitation Medicine In New York In -ewing the 843 patients with hemip1egi.a who received
rehabilitation at this institute between 196% and 1977, a 20% decline in prcsatption of lower extremity
orthoses of all types was aIso reported, The percentage of ambulatory cIients receiving any form of lower
e.x-mity orthosis declined from 65% in 1968-1969 to 43 -5% in 19764977 (Ofir & Sea 1980)- Note that
the prescription of different orthosis types vatl*es between regions and rehabilitation cenues; in I974
Waters and Montgomery still identified the double upright metal AFO as "the orthosis of choice for most
patients" (Waters & Montgomery, 1974)-
Today there are several d i f f i t designs of AFOs avaiIabie; the materials and components
chosen are determined by the type of control or assistance desired at the ankle-foot complex (Leonard er
al., 1989). Orthoses that provide a posterior or plantarfIexion stop M t ankle movement into
piantarflexion- This simulates the action of the foot dorsiflexors and allows for toe pickup during the
swing phase. The plantarfle~on stop aIso simulates the lengthening conrraction ofthe foot dorsiflexors
during the heel mike phase. SimiIarIy, an anterior or doflexion stop simuIates gastrocnemius and
soleus function by limiting ankle movement into dorsiflexion- In using an AFO to correct footdrop, the
ankle should be set at an angle which is just sufficient to provide adequate toe clearance during swing-
The greater the plantarflexion stop at the ankle, the more toe clearance is provided- However, a greater
plantarfledon stop also results in greater instability at the knee during heelstrike. Because plantarflexion
at the ankle is fe~ttl~cted, there is a greater tendency for the knee to buckle into flexion (Lehmann, 1979).
Although metal AFOs are less common today, they remain in use for certain applications. The
bichannel adjustable ankle locking (BiCAAL) AFO is used primarily to enhance tiiial or subtalar joint
control in stance, but can also facilitate toe clearance d w h g midswing by providing control of the foot
(Nawoczenski & Epler, 1997)- This is a double upright metal orthosis which features adjustable anterior
and posterior stops to control dorsinexion and plantarflexion respectively (Goldberg & Xsu, 1997; Waters
& Montgomery, 1974). The brace can be locked at a specific angle, or movement can be alIowed within a
designated ankle range- The adjustability of this orthosis may be advantageous for individuals with recent
neurologicaI involvement whose fixnctional abilities are still evolving. Disadvantages incIude its lack of
cosmetic appeal, as we11 as the inability to exchange foamear, since it is attached externally to a sturdy
shoe. The weight of the brace ranges between 2.5 and 4-0 pounds, which can make it inappropriate for
individuals with limited hip flexion. Mediolateral stability is provided by the shoe and stirrup attachment,
which can be reinforced as needed (Nawoczenski & EpIer, 1997).
Plastic orthoses are more cosmetically acceptable than the BiCAAL orthosis and are lighter in
weight, These orthoses are worn -de the shoe, on be completely covered by a sock or pantleg, and are
not restricted to a single pair of shoes- To maintain the biomechanical advantages provided by the AFO,
however, different pairs ofshoes should provide a consistent heel height, To accommodate the orthosis,
footwear which is a half size wider and longer than the foot may be required (Nawoczenski & Epler,
1997)- Plastic AFOs are fabricated fiom polypropylene or similar thermo-formable polymer materials
(Goldberg & &1997), Mediolateral stability can be controlled by the height of the ankle vimlines to
each side of the AFO, as well as the thickness of the material itself (Nawoczenski & Epler, 1997)-
Rigid plastic orthoses are fixed at a predetermined ankle angIe which prevents both dorsiflexion
and plantarflexion. thus providing the equivalent of anterior and posterior stops. However, unlike the pin
stops in standard double upright orthoses, the rigid plastic orthosis cannot be adjusted and must be
custom-molded to the appropriate angle (Lehmann, 1979). This type of AFO essentially eliminates all
ankle joint motion, which is disadvantageous for tasks that traditionally require ankle flexibility and
prohiiits the development of ankle muscle strength (Nawoczenski & Epler, 1997). For example, the
-tion from sitting to standing is usually initiated with the anWe in dorsiflexion (Schenkman, Berger,
Riley, er al., 1990); individuals wearing a rigid AFO must adopt new movement strategies for such tasks-
The current AFO of choice for the comedon of footdrop is a custom-fabricated, thermoplastic,
lunged orthosis. The hinged orthosis has a plantarflexion stop to restrict plantarflexion during swing just
enough to allow toe clearance, but allows considerable range of dorsiflesion during weightbearing and
pushoff. The orthosis is worn inside the shoe and posterior to the a, and is attached to the leg with one
or two velcro straps. The ToeOff AFO is prefabricated in three sizes, and made of a glass fiber, carbon
fiber and Kevlar compound. It is also worn inside the shoe but at the anterior side of the leg, bridging the
ankle and preventing plantarflexion. The absence of materiaf at the back of the leg is expected to enhance
comfort by avoiding contact with sensitive areas such as the Achilles tendon, the heel and the malleoli
(Wilinet & Smits, 1998)- The orthosis is thin, which should allow use in normaI shoes (Wlllner & Smiy
1998), is attached with v e h straps, and is Lightweight- Lighter weight and the ability to use orthoses in
different types of shoes have preyiously been identified by users as attn'butes (ICrebs et al., 1988)-
Disadvantages of using any orthoses indude their additional weight, negative cosmetic appeal
especialIy for women, restriction in shoe selection, and possl'bIe wear of clothing against external pans
(Ofir & Sell, 1980). Other factors aecting utilization of orthoses include comfort, appearance,
simplicity, efficiency, reliability, and ease of application and removal (HaiIey, 1995)- The biomechanical
advantages provided by the orthosis must cIearIy outweigh its dkbmtages fbr it to be accepted by the
user; individuals will seldom wear an orthosis unless it allows an important function which cannot
otherwise be achieved
2.4.2 Evaluation of Ankle Foot Orthoses
2.4.2.1 Gait Analysis
Walking can be descnid as a regularly recurring sequence of events known as the gait cycle.
This cycle is defined as the series of events that occurs fiom the initial contact of one foot to the next
initial contact of the same foot, Gait analysis is used to characterize and quantifi. elements of the gait
cycle. Along with simple elements such as step Iengtlk stride length, mide width and cadence, more
complex data such as forces aad angular movements of the joints can be recorded (Rose & GambIe, 1994).
Video-based motion analysis is commonly used to provide accurate descriptions of the kinematic
and kinetic parameters of gait (Harris & Wertsclh 1994). The results of gait analysis have previously been
used as outcome measures in studies involving stroke survivors (Colborne, Olney, & G M h , 1993;
Karimi, 1996; Olney, Colborne, & Martin, 1989; Teiseira, 1998)- The Peak Motus motion analysis
system, developed by Peak Performance Technologies Incorporated, is a standardized video-based
computerized system that can anaiyze motion in two- and three-dimensional space, and has successfUy
been used in previous research to analyze the gait of stroke survivors (Colborne et 02-, 1993; Karimi,
1996; Olney et al., 1989; Olney, GrifEn, & McBride* 1994; Olney, Griffin, Monga, & McBride, 199 1;
duration, but diminishes push+ff duration relative to an orthosir fixed in slight pIan&lexion
Conversely, an orthosis fixed in slight plantarflexion increases the push-off pbase but diminishes
heelstrike and midstance duration (Lehmann, 1993)-
2.4.2.2 Energy Expenditure
It is espxted that an effective AFO will decrease the energy costs -at& with locomotion
(Nawuczenski & Epler, t 997), thereby increasing independence and participation in daily activities- Any
orthosis that increases the &on required to walk is likely to be discarded (Stidlard, Rose, Tait, & Davies,
1978). Similarly, patients who derive onfy marginal energy savings from orthoses may &so demonstrate
poor compliance, unless pain or instability is decreased (Mossberg, Linton, & Friske, 1990). It is assumed
that an effective AFO will enhance quality of life by improving walking abilities and ability to participate
in daily activities,
Measurement of the energy eqended while walking can provide objective data to help assess the
effectiveness of therapeutic interventions such as orthotic prescriptions (Rose Gamble, Lee, Lee, &
Kaskell, 1991)- The traditional measure of energy expenditure is the rate of o.vgen uptake fiom inspired
air (Rose et of., 1991). However, these measurements are ~ c u k in a ciinical setting, and even less
feasible during daily activities. Measurements of heart rate and waking speed are clinically feasible.
Furthermore, a high correlation between heart rate and oxygen consumption has been found during
submashal work such as walking- Heart rate has been used to estimate the energy costs of ambdation,
and has been proven a reliabte indicator of energy espenditure (Rose, Gamble, Medeiros, Burgos, &
Haskell, 1989; Rose, Medeiros, & Parker, 1985).
The physiological cost index (PCI) is an indes of energy expenditure based on the ratio of the
heart rate increase above resting to the velocity of ambulatioor
PC1 (beatdmetre) = Waikin~ heart rate&eats/minute) - Resting heart rate(beatdminute1 Speed (meWminute)
PC1 has been used in controlled environments to investigate energy expenditure over a range ofwalking
speeds. A study of 3 1 n o d adults aged 53 to 85 found good test-retest reliability for PCL at scIf-seIected
slow ( ~ 8 l8), comfortable (r=868) and fist (F-845) wvaIking speeds (Chen, L997). PC1 has been used to
evaluate orthoses; using this index, Mossberg ec aL (1990) found that the use of ankle-foot orthoses
(AFOs) with spastic diplegic children reduced the energy costs associated with walking.
The weight of orthotic appliances also influences energy expenditure- In addition to prehhary
gait studies which suggest that ToeOffmay enhance walking capacities, the extremely: light weight
(-125g) of this AFO was to contribute to a reduction in the energy cost of ambuiation ( W i i &
Smits, 1998). Barnett et aI- (1993) demonstrated that oxygen consumption per unit distance shows a
significant positive correlation with added ankle weight (p-c0.001), while walking velocity exhibits a
simcant decrease when correlated with added ankle weight @=0.03). This suggests that minimizing
the weight of AFOs should maximize fhctional walking speed and minimize energy expenditure-
2.4.2.3 Walking Tests
The time required to cover a prescribed distance, or the distance covered in a pcescn'bed time,
have also been used to evaluate the fimctional e!ktiveness of AFOs (Krebs et al-, 1988). Walking tests
are usually performed on a level surface for a specified time period which usually ranges fiom 6 to 12
minutes. Compared to conventional exercise testing, walkiag tests may better reflect an individual's
ability to undertake physically demanding acthities in everyday life (Steele, 19%)- Timed walks of2,6,
and 12 minutes duration have been found highly reproduaile and well correlated with each other
(Butland, Pang, Gross, Wwdcock, & Geddes, 1982; Provenier & Jordaens, 1994)- While the 2-minute
walk may effettively measure bursts of effort, longer tests are more appropriate to evaluate physical
endurance. Steele (1996) suggests that the 6-minute test is long enough to incorporate some measure of
endurance, yet short enough to facilitate administration and tolerance by patients whose physical
capacities are limit&
2.4.2.4 Questionnaires
Questionnaires are a popular method of colIecting subjective f-ck In the case of lower limb
orthoses, the issues most commonly explored in subjective tvaluations have been physical comfort, ease of
application, hction, and aesthetic appeal, Fisher and McLeIIan (1989) dimiiuted a questionnaire
evaluating comfort, function, and cosmetic acceptability of lower limb orthoses to consumers, reporting
that the level of patient satisfaction was usually associated with frequency of wear. In evaluating anterior
cruciate Ligament braces, Alexander (1995) determined subjective scores in the a-eas of comfort (freedom
from slippage, abrasions, and pressure phenomena), commience (ease of application), control (perceived
resistance to anterior tibia1 translation), and cosmesis (appearance).
Krebs et ul- (1988) compared plastic-metal and leather-metal knee-ankle-foot orthoses, coUecting
measurements of gait and fhctional activities as well as soliciting opinions regarding ease of donning,
perception of orthotic weight, comfort, stability, walking ease, speed and appearance- These authors used
comparative and noncompmtive rating scales to obtain subjective reactions about the two orthoses. The
comparative rating s d e asked the user to indicate a preference for one of the two orthoses, or no
preference, for each of the characteristics being evaluated The noncomparative rating scale asked users
to evaluate each orthosis independently, and solicited ratings of orthosis characteristics on a 5-point Likert
scale.
Subjective evaluations have been used to substantiate the results of fhctional evaiuations, as well
as to determine the impact of AFO usage on daily activities. Diamond and Ottenbacher (1990) reported
changes in stride clwacteristics as a result of AFO usage; these changes were subjectively substantiated by
subjects who reported an improved ability to walk longer distances, as well as greater comfort and less
restriction during daily activities- Using a questionnaire, Waring et aL (1989) examined pain, fatigue and
ambulation of 104 postpolio subjects, finding that an appropriate AFO not ody improved the ability to
walk, but also increased perceived safety and reduced knee and overall pain,
2.4.2.5 Focus Groups
Increasinglyy developers of rehabilitation technology are condting with experienced users of
assistive dMces in order to their experiences and benet assess their needs and prderences
(Batavia & Hammer, 1990)- Persons who have recently become disabIcd must first determine their
changed needs, before they can assess technologies that may help compensate for firnctional limitations.
In contrasf experienced users ofassistive dewices possess a wealth of knowfedge that can be very vaiuabie
to the designer, These individuals have obtained an assistive device through a dhkdLyadlded or persod
selection process, have used this device, and are awaxe of its strengths and Inadequacies in relation to their
own needs.
Although the use of focus groups to explore user satisfaction with ankle foot orthoses specifically
has not been reported in the literature, qd-tative approaches arc becoming recognized as a valuable
compiement to existing quantitative techniques for the evaluation of technology (Levy, 1987; Scherer &
Lane, 1997)- Qualitative methods have recently been used to e\~lore concerns of stroke patients about
assistive device use (Gitiin, Luborsky, & Schemm, 1998), as well as seniors' views on the use of assistive
devices in fall prwention (Amiazadeh & Edwards, 1998)- In both studies, participants' comments
provided valuable insight into their perceptions of the need, utility, and social context of assistive device
use.
CHAPTER 3. Methodology
3.1 Participants
Participants were recruited fiom clients p-oudy prescribed AFOs through the Prosthetics and
Orthotics Clinic now at St M.ary's ofthe Lake Hospital (SMOL) in Kingston, -0- Persons who were
prescn'bed an AFO for footdrop resulting h m neurological conditions wexe invited to -cipate- To
ensure that participants were experienced AFO users with relatively stable conditions, persons were
contacted if they had been using their current AFO for at least three months Other inclusion criteria were
the ability to walk for at least 15 minutes, with rests, and the ability to complete a log ofdaily activities,
with or without assistance- Because many of the stroke survivors had only one hct ional hand which may
have been their nondominant hand, sometimes a spouse or W I y member assisted with completion of the
Activity Record (ActRe)- In all cases where a person other than the primary participant filled out the
ActRe forms. this assistant was involved in completing the sample time period entry (see &on 3.4 for
Activity Record metlmdology) to ensure that he or she was simply acting as a scri'be and that the validity
of the data being collected was maintained, Two early participants were unable to wear the ToeOff
orthosis because of spasticity; severe ankle plantarflexor spasticity or toe clawing were subsequently used
as escIusion criterion,
The first six participants were a sample ofcomenience recruited from stroke survivors who had
participated in previous research at the School of Rehabilitation Therapy in Kingston, Ontario- These
were individuals known to be wearing an AFO, and who were screened for meeting the inclusion criteria
by the referring researcher. Subsequent participants were referred by the physiotherapy department at
SMOL in Kingston, Ontario- The protocol and objectives of the study were esplained to the therapists,
who referred clients whom they deemed appropriate and who expressed interest in participating to the
author. When a potential participant mas referred, the author contacted him or her by teIeplmne and
esplained the protocol of the research, as well as doing a second screening that the inclusion criteria were
satisfied. Although the initial participants were stroke survivors, the physiotherapists at SMOL were
invited to refer any client with footdrop whom they felt would be appropriate for the current study.
Ofthe 16 persons recruited, 13 had suffkred a s f r o k one had peripW neuropathy due to
trauma, one had multiple sclerosis, and one had a back iitjury- Two of the stroke SUIYiYors were unable to
wear the ToeOfforthosis due to spasticity, and two individuals voluntarily mathdrew fiom the study, for
reasons unrelated to orthosis fiurctioe The individual with multiple sclerosis was also unable to wear the
ToeOff AFO, is no longer wearing any orthosis, and p-iy bas made accomodations to her gait using
her very limited muscle strength that cannot be carried out when wearing any orthosis. A final sample
size of 1 1 participants trialed the Toeoff AFO-
The protocoL for this research was approved by the Human Research Ethics Board at Queen's
University- The objectives of the study and methodology were clearly explained to each participant, who
was then given the opportunity to seek clarification Prior to kginning the study, each participant
completed a consent fonn (Appendix B), Demographic information was collected on a subject
information fonn (Appendix C). These forms were completed at the first visit, along with the initial
walking tests with the original AFO and the sample ActRe f o m Each participant then completed ActRe
forms over two consecutive weekdays when wearing the original N O - The author contacted each
participant on the fim day of Act& completion to answer any questions which might have arisen. Fitting
of the ToeO£forthosis was then scheduled at SMOL, after which follow-up visits for individual
adjustments were scheduled as necessary. After a minimum of one week and after participants felt that
they had accomodated to the ToeOff AFO, and that any necessary adjustments had been made, a third
visit was scheduld Prior to this third visit, Act& forms were completed over two consecutive weekdays
when wearing the ToeOff AFO. Again the author contacted participants on the first day of ActRe
completion to answer questions which might have arisen, At the third visit, walking tests were performed
with the ToeOff AFO. Focus groups were scheduled after participants had worn the Toeoff AFO for at
least two weeks, and once there were enough users to have a small discussion, The clinical assessment
was scheduIed when an appointment was available at the Queen's Physiotherapy CIinic, usually
immediately following one of the nvo walking tests-
3.2 Gait Analysis
Gait analysis was performed in the Motion Laboratory at Queen's University- Two participants
were selected for gait analysis, one whose measures ofenergy expenditure (see section 3 -3-L for
measurement of energy espenditure) indicated a positive result, and one whose measures of energy
expenditure indicated a negative result, These participants were selected by convenience, according to
who was available and willing to make the additionai two visits Analysis was performed at the same time
on two consecutive days- N o d cadence for each orthosis was predetermined and matched throughout
gait analysis by using a metronome, Participants were first tested with the orthosis they were currently
wearing, then wore the other orthosis until the next testing session,
Prior to data collection, passive reflective d e r s were placed on the cameta-side fifth
metatarsal, ankle lateral malleolus, lateral epicondyle of the femur, greater trochanter, and the lateral side
of the neck at C7. These markers were used for subsequent digitizing of joint position. Two markers
were also attached to the side of the walkwayp providing a level ground reference- Participants wore a
black vest and shorts, which m a x h k d recognition of reflective matkers during the digitizing process.
To minimize reflections from the white plastic orthosis, the AFO was also covered by a black cloth,
The Peak Motus hvoimen~iond motion analysis system (Peak Performance Technologies Inc.,
Englewmd, CO) and an AMTI (Advanced Medical TechnoIogies hc.. Newton, MA) force plate were
used to collect the kinematic and kinetic information required for gait analysis. Participants were
videotaped as tl1ey walked along an 8-metre platform in which the force plate was embedded- Three trials
were collected for each side; an acceptable triaI was one in which the foot closest to the camera landed
completely within the force plate, without the other foot making contact- Finally, participants were asked
to stand stiI1 in the inid& of the platform and were videotaped fiom the left and right sagittal view-
These frames were used to adjust the relative ankle and foot segment angles, since the ankle to metatarsal
angle with the foot flat on the ground would not provide a neutral (OQj fmt angle.
Videotaping was performed by a super VHS video camera (Hitacl~ VM-6100A SVHS, Japan),
which was located 4.8 metres fiom the piatform and had a sampling rate of 60 fiames per second- The
camera was mounted on a tracking a r t perpendicular to the walkway and positioned such that one
complete gait cycle was within the field of view, A light projector was also mounted on the tracking cart
and illuminated the reflective markers during data couection. Force plate data were sampled at 1200 EIt,
converted to digital form, and stored on a computer together with a syncbtonizing sign& p- by the
camera To allow synchronization ofvideo and force plate data, the camera signal simultaneously created
a digital code on each frame ofvideo data The video and force plate data were combined to &date the
vertical and fore-afi shear ground reaction forces, as well as the centre of pressure of the force vector-
Coordinates for the dect ive markers were digitized for each h e of video data. In order to
provide sufficient data for the filtering process, LO fiames prior to and foLIowing camemside foot
contact were also d i g i M The coordinate data were digitally filtered using a secondarclet low-pass
Buttenvorth fiIter, and were subsequently processed to determine kinematic and kinetic variables- A
customized biomechanical software package, "Q-KZN-2D," performed these caiculations This software
was developed at the School of Rehabilitation Therapy at Queen's University, and employed a standard
four-segment link segment model with anthpometric values recommended by (Dempster, 1955)-
Resulting kinematic variables included relative angles of the hip, knee, and ankle, along with foot
segment angles, Calculated kinetic variables included the net moments, powers and work at each joint
Net joint power was calculated as the product of the net moment across the joint and the relative angular
velocity behveen the adjacent limb segments- Positive and negative work at each joint were obtained fiom
integrals of the positive and negative joint power curves (Winter, 1990)- Kinetic data were normalized by
dividing each value by the participant's body mass, and the data for each stride were standardized to one
point for each 1% of the gait cycle.
Gait analysis will indicate whether ToeOffprovides a power advantage during push-oc and
whether one AFO more closely approximates the biomechanics of normal ambulation- Gait profiles of
healthy adults walking at similar speeds have been produced using identical instrumentation and software
(Winter. 199 l), and will be presented in the resuIts section for comparative purposes- Combined with
clinical assessment data, this information will allow the determination of what type of user benefits most
fiom ToeOff' Since the ankle plantarflesor muscles are the major s o m e of power during push-off (Olney
& Colborne, 1987), it is e.upected tbat users with reduced ankle plantarfle~or strength wiU benefit most
h r n T-
3.3 Walking Tests
It was expected that the ToeOfforthosis would decrease the energy costs with walking,
as well as improve participation in daily activities- The physiologkaX cost index (PC0 was used as a
mearmre of energy costs, while a daily activity record (ActRe) provided quantifiable information about
daily activities, including Ievels of p h W d acitivity and &ti-e experienced whiTe performing them,
3.3.1 Physiological Cost Index
The physiological cost index (PCI) is the ratio of heart rate increase above resting to wallring
speed. It w a s hypothesised that the physiological cost of walking would be lower when w e a ~ g the
ToeOff AFO. TIUS couId be reflected by either a lower PC1 and a similar walking speed, or a similar PC1
and a faster walking speed, when wearing the ToeOff orthosis. The PC1 was calculated for each
participant at ~e~selected comfortable and fast wvaking speeds- While the self-selected comfortable
walking speed is intended to approximate no& walking speed during daily activities, calculation of PC1
at self-selected fast speeds provides information about the range of walking speeds of which the subject is
capable. A more effective AFO may allow a greater range of waking speeds-
To determine PC& two 6-minute walks were performed in the hallway ofthe Louise D- Acton
building at Queen's University. A Polar Vantage XI. hem rate monitor (Polar CIC, Inc., Port
Washington, NY) was worn around the participant's chest and recorded the heart rate every 15 seconds
throughout the trials. A digital stopwatch was used to time the walking trials, and was synchronized with
the heart rate monitor at the beginning of each walk To determine the resting heart rate, each participant
rested in a seated position for 5 minutes or until the heart rate had become stable. The first 6-minute trial
was performed at the self-sdected fast speed, and the second at the self-selected comfortable speed-
Subjects rested for a minimum of 5 minutes behveen each walking trial and until the heart rate had
retmned to within * bcaWminute of the resting heart rate Toml dZstancc and dhtancc travelled enry 2
minutes were recorded
During the trial, subjects walked back and forth along the 38-metre conidor; Cokn et al, (1990)
found that incorporating a turn into a timed walk accentuated clinical difticulties in turning and changing
diredons without aEiting its reliability, For the fim trial, participants were instructed to cover as much
ground as possi'bie during the 6 minutes; for the second, they were asked to walk at their nonnal,
comfortable walking pace- Because encouragement has a signiscant efTect on walking test performance
(Guyatt, Pugsley, & SullEvan, 1984; Steele, 1996), encouragement was stan- across all trials-
During t l~e walks, a briefphrase of encouragement such as "you're doing welI," "very good," "keep up the
good work* or ').ou're doing fine," was provided every 30 seconds,
3.3.2 Six-Minute Walking Test
An orthosis which returns energy to the user may permit a faster walking speed. The maximum
distance wluch can be covered in s is minutes also lm functional implications, for example navigating
across busy intersections or shopping malls, or hurrying to catch a bus. The six-minute walking test was
performed concurrently with the fim PC1 trial, using the methodology d e s c r i i above-
3.4 Activity Record
In evaluating the eff 'veness of an AFO, measurements should not be timiteti to a laboratory
setting, but should extend to the user's daily environment, Developed by the National Institutes of Health
(NM), the Achvity Record (ActRe) is a ~e~adrninistered daily log of activities which provides
quantifiable information regarding specific activities and activity categories as well as the level of physical
effort required for each task. This log is completed during daily activities, and has previously been used to
assess energy conservation (Gerber & Furst, f 987)- Significant correlations have been found between
fatigue measured by ActRe and by the Feeling Tone Checklist ( ~ 0 . 5 5 , p=0.028); pain measured by
ActRe, the Pain and Disability I n d e ~ (r=0,66, @.002), the Ritchie Articular Index ( ~ 0 - 7 6 , @.0001)
and the visuaI analog scale in the ModifiedHealth Assessment -onnaire (r-0-73, p=0.0002) (Gerber
& Furst, 1992a; Gerber & Funt, 1992b).
Using a daily log format, the ActRe quantifies how much physicai activity an individual is
engaging in, and whether each activity is associated with pain or fatigue. The ActRe was originally
developed as an outcome measure for patients with rheumatoid arthritis who participated in a clinical trial
testing the efficacy of an energy consexvation program (Gerber & Funt, 1992b). Using the ActRe as an
outcome measure to determine the number of subjects improved or not improved, the treatment p u p
improved for rest during physicai activity @=0-07), balance between rest and physical ~ v i t y @=O. 1)-
and time spent physidy active p0.1) (Furst, Gerber, Smith, & Fisher, 1987)-
In this study the ActRe was used as a measure of daily activity levels with both the originaily
prescribed AFO and the ToeOff AFO. This should indicate whether any potential difference between
energy expenditure with each AFO, as measured by the physiological cost index, is translated into
activities of daily living, Furthermore, even where there was no Merence between AFOs as measured
within the constraints of a laboratory setting, the greater comfort provided by one AFO, for example,
might allow increased participation in activities tluoughout a 24-hour day. The ActRe was modified to
include one additional question to be answered for each -hour: 'Dwlng this time I was wearing my
foot brace; l=Yes, 2=NoY (Appendix E), to allow quantification of differences in frequency of wear
between onhoses. A greater frequency of wear for one orthosis may indicate higher patient satisfaction
with this device.
The instructions for completing the ActRe (Appendix E) were discussed in detaiI with each
participant, who then completed a sample time period entry, Each page of the ActRe includes a column of
half-hour time intervals for which the subject filled in corresponding activities, a Key column indicating
level of physical activity, a Caregory column indicating type of activity, and eight questions to be
answered for each haif-hour period escept for sleep, The sample entry was checked for accuracy and
understanding of instructions (Getber & Furst, 1992b)-
Participants completed the ActRe at home on two consecutive weekdays for each orthosis. To
improve accuracy, participants were &ed to complete the log at lunch for the morning, dinner for the
afternoon. and bedtime for the evening (Gerber & Futst, 1992b)- On the first day of data coIlection,
participants were contacted by telephone to ask if they had any questions.
3.5 Questionnaires
Comparative and noncomparatEve rating scales evaluating comfort, function, appearance and
application (Appendix F) were designed and administered verbally. The questionnaires were reviewed by
an occupational tI1erapist The noncomparative rating scale was completed prior to the six-minute walk
with each orthotis. The comparative rating scale was completed by telephone, after the user bad W e d
the T o m for at least two months- Participants who were unable to use stairs or did not walk on uneven
ground did not answer questions related to these activities- Explanatory comments made by mcipants
while rating the orthoses were noted on the forms,
3.6 Focus Groups
Focus groups are a common method of collecting consumer opinions about products, allowing for
direct interaction with participants which provides opportunities for follow-up questions and clarification
of responses. A typical focus group lasts from 1.5 to 2-5 hours and involves 8 to 12 individuals who
discuss a specific topic under the direction of a moderator, As weU as providing data fiom individual
conteas in the respondents' own words, focus groups allow for interaction between group members and
may provide ideas that might not have been uncovered in individual interviews or questionnaires (Stewart
& Shamdasani, 1990)-
Focus groups were scheduled after each participant had trialed ToeOflF for at least two weeks-
Due to difficulties in scheduling participants, many of whom were travelling considerable distances, each
focus group consisted of 2 to 4 participants. Using two small focus groups of individuals with disabilities,
Batavia & Hammer (1990) identified 17 general fsctors which are important in the evaluation ofassistive
devices- Across a range of technologies which included mobility devices, effectiveness, afFordability,
operability and dependability were ranked on average as the four most important evaluation criteria A
pre-determined interview guide was created from these criteria, as well as duation criteria specific to
AFOs (Appendi~ G).
The focus groups were held at Queen's Universityr in the Clinical Learning Ctntrc when
available. or in the conference room of the Louise D. Acton building- Two focus groups were heId at each
location Desks were arranged to approximate a circular conformation, Participants were encouraged to
share both negative and positive comments, and to provide concrete examples of performane during daiIy
activities- Each session was videotaped to allow later tramcription and caphue visuaI information, since
participants often pointed to a pdclllar AFO or to part of one AFO when speaking.
3.7 Clinical Assessment
A clinical assessment (Appendix D) of each participant was conducted by an experienced
physiotherapist at the PhysicaI Therapy Clinic at Qwen's University, with the assistance of the author.
The same physiotherapist performed all assessments, The objective of the clinical assessment was to
attempt to differentiate between participants who were and were not succeSdid, in tenns of PC1 results,
with the ToeOE ortlmsis, Range of motion and muscle strength of the affiected ankle, knee, and hip joints
were evaluated, Spasticity was measured using the Modified Ashworth Scale and the Pendulum Test;
ankle stability and somatosensory h c t i o n were also tested and reported as either intact or impaired
(Appendix D). Testing positions for both range of motion and manual muscle testing were standardized
according to the literature (Bohannon, 1986; Bohannon, 1 WOb) and after consultation with an
experienced stroke therapist (Martin, 1998)-
3.7.1 Range of Motion
A c k and passive range of motion were measured using a clear plastic 360° universal
goniometer with 12,71cm moveable arms and a scale marked in lo increments. The literature indicates
that universal goniometer measurements of passive ankle dorsiflesion and plantarflexion are reliable
(Elveru. Rothstein, & Lamb, 1988; Pandya et a/-, 1985)- Measurements of active ankle dorsiflexion and
plantarflesion ace also refiable, when made by the same phyn'cal therapist Repeated measurements of 38
patients by 10 physical therapists yielded a median intraclass correlation wefiicient (KC) of ,825 for
active W e dorsiflesion and -863 for active ankk plantatnexion (Youdas, Bogard, & Suman, 1993).
Excellent intratester reliability for passive knee range of motion has been obtained (Watkins, Riddlq
Lamb, & Personius, 1991), while average intratester reliability of4 testers taking goniometer
measurements on 12 volunteers over 4 was -869 for active knee extension-flexion (Bone et al-,
1978). For passive hip flexion, excellent intfasessl*on (-94) and intersession (.€IS) reliabiIities were
obtained with a standard goniometer Weh, Walker, & Giilis, 1983); Bierma-Zeinstra ef al. (1998) found
good inmobserver reliabilities using a goniometer for both passive and active hip movements- Using a
standard goniometer, a single eqerienced tester measured 20 volunteers over 5 sessions and demonstrated
good ICCs for hip flexion (-95) and extension (.83), knee flexion (-95) and extension (-83, and ankle
dorsiflesion (-92) and plantarflexion (-96) (Clapper & Wolf, 1988)- In general, goniomeaic
measurements are accurate to within 5 degrees for lower extremity movements (Clapper & Wolf; 1988;
Mayerson & Milano, 1984); Boone et al. (1978) suggest that a change of at least 3-4 degrees is required to
detect a real clwge in range of motion, when measured by a single tester.
3.7.2 Muscle Strength
Although manual muscle testing is the most widely used chkal assessment of muscle strength
(Marino, Nicholas, & Gleim, 1982), it is less capable of discriminating small Werences in muscle
strength than dynamometric testing (Wadswortlb Krishnan, Sear, Harrold, & Nielsen, 1987). Since the
degree of difference between individuals who did and did not achieve positive results with the ToeOff
orthosis was not knowg a simple yet more objective measure of muscle strength was chosen- Muscle
strength was assessed using a hand-held dynamometer produced by Penny & Giles Transducers, with a
force measurement range of 30 kg. All measurements were made using a 'make test', in which the subject
eserts maximum force against the stationary dynamometer for approsimately 5 seconds (Wadsworth et
al., 1987). This duration was show to be sufficient for most individuals to attain maychum force
(Bo~MMo~. 1990~)- The other common strength test is the 'break test', in which the subject maintains a
prescribed position while the tester attempts to counterbalance or break tl* position- This test was not
chosen because it is -ated with an hmcasd likelihood ofdtlayca muscfe softness, and because
measured forces may be partly lndicatlve of muscle tone rather than strength alone (Eohannon, 1990b)-
Since band-held dynamometry requires that the tester hold the dynamometer daring testing, its
validity is limited by her strength and technique- That isT If the strength of the tested muscle groups
esceeds the ability ofthe tester to stabilize the person being tested, the measured force will reflect the
limitations of the tester rather than the actual strength of the tested muscle groups. Even ifthe tester is
not overpowered, force readings tend to be relative to tester strength (Bohannon, 1990b). For this reason,
the same physiotherapist performed all measurements. Ifthe tested muscfe p u p overpowered the tester*
'too strong' was recorded on the assessment f o m Since the objective of ch id assessment was to
differentiate those participants who benefitted most from the ToeOEorthosis, merentiation of muscle
strength within the normal range was not nece~~azy~
Hand-held dynamometer measurements have been correlated with other methods of m e a . g
muscle strength. Results of Ekd and hand-heId dynamometers have been correlated (F-86; p<.OOI)
(Hyde, Scott, & Goddard, 1983)- Similarly, measurements of knee extension torque performed with a
hand-held dynamometer and Cybex 11 isokinetic dynamometer did not diftier significantly and
demonstrated a fair intraclass correlation (-797) (Bohamon, 1990a). The reliability of repeated hand-held
dynamometer measurements Ins also been established, The test-retest reliability of intrasession
measurements obtained by a single e-upen'enced e.uaminer using 'make' tests was -945 or greater for ankle
dorsiflexion, knee extension, and Iup flesion (Bolmon, 1997). VaIues for ankle plantarflexion, knee
flesion, and hip exqension were not reported in this study, however another (Bohannon, 1986) reported
intrasession reliabilities of -93 or greater for all 6 muscle groups evaluated in the clinical assessment.
Intersession reIiabiIities are somewhat Iower, which may partly reflect temporal variation in external
factors such as pain and motivation; Wadsvorth et al- (1987) reported intersession reliabilities of -72 and
-75 for hip and knee flexors of 11 patients, when tested initially and then again two days later-
3.7.3 Spasticity
Although moderate to severe spasticity was identified as a contraindcatioa for Toeoff
(International Orthopaedic Marketing L998), it is not known what degree of ~ ~ & c i t y can be
accommodated by the orthosis. Two measures of spasticity were incorporated into the clinical assessment,
in an attempt to determine the degree of spasticity which is acceptable, Spasticity of the ankle
pIantarfle..ors was asessed using the Modified Ashworth Scale (Table 3. l), while spasticity of the
quadriceps was evaluated with a manual Pendulum Test TheAshworth rating was made with the
with the participant in seated position
Spasticity can be defined as a velocity dependent increase in the resistance of muscles to passive
stretch, and is associated with esaggerated tendon jerks resulting Erom upper motor neuron damage (Katz
& Rymer, 1989). A spastic muscle resists passive stretch at a shoner Iength than n o d musde (OIney &
Wright. 1994). The clinical measurement of spasticity involves estimating the amount of resistance to
Table 3.1 Modified Ashworth Scale (Bohannon a Smith, 1987)
Grade Description
0 No increase in muscle tone
I Slight increase in muscle tone. manifested by a catch and release or by minimal
resistance at the end of the range of motion when the affated part(s) is moved in flexion
or estension
1+ Slight increase in muscle tone, manifested by a catch, followed by minimal resistance
throughout the remainder (less than half) of the range of motion
2 More marked increase in muscle tone through most of the range of motion, but affected
part@) easily moved
3 Considerable increase in muscle tone, passive movement difficult
1 Affected paxt(s) rigid in flexion or e-\?ension
passive movement, and is largely subjective (SIoan, S inck , Thompson, Taylor, & Pentland, 1992)-
Since muscle resistance to pasdve stretch is dependent on the velocity at which the joint is moved, a
standardized velocity would be required to ensure reliability of gradings (Haas & Crow, 1995)- The
Ashworth Scale is the most frequently cited spasticity grading scale in the literature, and is commonly
used for the assessment of muscle tone in individuals with hemipIegia (Bohannon & Smith, 1987; SIoan
et a!., 1992). In a study of 12 patien& Lee et of. (1989) reported that the Ashworth Scale yields reliable
and reproduclile results- The Modified Ashworth ScaIe was reported by Bohannon and Smith (1987),
who added an additional level of grading (I+) to differentiate between patients at the lower end of the
scale, and slightly modified the associated descriptions pabk 3.1)- This scale is ordinal and ranges h m
normal muscle tone (grade 0), to such a severe increase in tone that the limb is rigid (grade 4).
ReliabiLity of the Modified Ashworth Scale has been asessed in severat studies- Bohannon and
Smith (1987) reported high inter-cater reliability (L-4.847; pc0.001) between two experienced testers
esamining the spasticity of elbow flexor muscles, In a study of spasticity in 34 persons with hemiplegia.
SIoan er a!. (1 992) reported correlations between four testers wluch ranged fiom 0.45 to 0-74. Inter-rater
correlations for elbow flexor and e\?ensor muscles (mean r 4-67 to 0.73, p-4.00 1) were higher than
those for knee flexors (mean r = 0-45, p<O.Ol). An investigation o f p l a n t d e ~ o r muscle spasticity in 30
patients with traumatic brain injury also used the MOdEed Ashworth Scale, and reported Spearman's
correlation coef£icients for interrater reliability (0.73), intmrater reliabiIity (0-74 and 0.55 for each of two
testers), and temporal reliability (0-82) (Allison, Abraham & Petersen, 1996)- Although the subjectivity
of ordinal scales make them Iess reliable than more sophisticated quantitative techniques, such scaIes are
simple to use and can be performed quickly and ine\pemiveIy.
Tl~e PenduIum Test is a simple, objective measure which has been used to assess spasticity of the
quadriceps muscle group, This test is performed with the subject in a seated position; the person's leg is
passively estended by the e-uaminer and supported until the individual appears rela~ed, then allowed to
saving freely and the number of oscillations counted. Initial displacement was measured using a manual
goniometer, and a relaxation index calculated as the amplitude of the initial displacement divided by the
final resting position- A study of LO hemiplegic and 10 control subjects found significant between group
merences in the number of oscillations (p0.025) and the relaxation index Q~0.004) (von &mpn &
Kriellaarsf 1996).
3.7.4 Other Clinical Measures
Four other simple cfical measures evaluated ankle stability and somatosensory function, which
were rated by an experienced physiotherapist as either intact or i m e AnkIe stability was evaluated in
two-foot stance, without orthosis or shoes. Stability was assesed by observing the participant visually,
and asking if he or she felt stable- The affiected foot was tested for sensation to Iight touch, with the pin
prick test (sensation of sharp and duIl), and for proprioception of the big toe, Participants were asked to
close their eyes during these latter three tests-
3.8 Data Analysis
All statistical tests were performed using SPSS 8.0.0 statistical software, ActRe results were
processed and the mean percentages of waking time in each activity category, when wearing each orthosis,
were determined Tests of skewness. kurtosis, and normality were performed to assess the normality of
each variable's distribution, Where appropriate, uansformations were made to improve the normality of
distributions before performing onetailed multivariate and univariate t-tests on paired data.
The Wilcoxon signed ranks test was used to test the probability of a higher median rating for the
ToeOE AFO on the noncomparative rating scale- Although the Wilcoxon signed ranks test is intended for
continuous data, it is often applied to Likert-scale data in health care research (Pett, 1997). Applying a
correction for ties to the Wilcoxon signed ranks test improves its applicability to noncontinuous data,
however given the small sample size in this study extensive m*pulation of data was not advised (Smith,
1999).
The binomial test was used to evaIuatc the probability of preference for the TmOfforthosis on
the comparative rating scale. This test is appropriate for determining the probability that the proportions
of the two levels of a dichotomous nominal variable occumd other than by chance. AFO preference was
collapsed into two m u W y exlusive categories in two ways. First, among participants who expressed a
preference for one of the two AFOs, the binomial test was applied to determine ifthe proportion of
patkipants eqxessing preference for the ToeOE AFO was statisticaUy greater than 50%, Second, among
all participants, the binomial test was applied to determine if the proportion ofparticipants expressing
preference for the ToeOEAFO, as opposed to part~kigants who cupfessed no preference or preference for
the original AFO, was statistically greater than 50%.
Statistical tests were not performed on the results of gait analysis, walking tests, or clinical
assessments, In these cases statistical sisnificance was not considered necessary for clinicd significance
to be achieved For the two participants who underwent m-t the joint, moment and power
profiles for the f l i e d and umffiected sides when wearing each AFO were compared with the expeaed
normal profiles from healthy adults walking at similar speeds- For each participant, differences benwen
the results with each orthosis were noted, and compared with the biomechanics of normal ambulation.
Results of the walking tests were esp- as the percentage difference in PCT, walking speed or distance
walked, behveen the two orthoses, For the PC1 results, a 10% change in either PC1 or walking speed was
assessed as cIinicaIly significant, since a 10% clwge in either PC1 or walking speed is clinically
noticeable (Olney, 1999). For the sis-minute wvalking test results, this ditrerentiator was set at 8%, since
there was a group of participants who showed very little change in the distance walked with each AFO
(less than 5% difference), and another group who showed differences of 8% or more- Furthermore, the
difference of 8% corresponded to a merence of 45 metres, which is clinically noticeable.
To facilitate analysis of clinical assessment data, individual results were organized into four
groups: persons demonstrating positive PC1 results or energy savings with ToeOff, persons demonstrating
negative PC1 results or additi0na.I energy cost with ToeOff, persons showing no change, in terms of PC1
results, with ToeOE, and persons unable to wear the ToeOEorthosis (see section 4-3 for explanation of
PC1 results), For range of motion. muscle strength and spasticity measures, group means and standard
deviations were determined. For ankle stability and somatosensory fimction, the percentage of individuals
witlain each group who were rated as impaired was reported, Results behveen the four groups were
compared and consistent differences between groups reported
Focus groups were Vansf& fiom videotape to ad-otape and t r a n s c n i The transcript was
then checked with the videotape to ensure accufacy, and notations, for example the brace to which the
speaker was pointing, were added in brackets- Data was then coded by the author using Nudist 4-0
qualitative analysis &ware- Since -pts consisted primarily of brief speeches of conversation, each
paragraph was defined as a text unit for analysis- Content analysis is the most common type of anaiysis
used in qualitative studies (Field k Morse, 1985), and was used to review each text unit and code the
sig-rlificant meanings within each passage, Two graduate students familiar with quaIitative analysis also
coded the first meen pages of the first two focus group ttanscripts- This coding was then compared with
that of the author, coding of all three petsons was very similar-
CHAPTER 4. Results
Following d-ption of the participants who tn'aled the ToeOa AFO, results of the various
methodologies empioyed to evafuate the ToeOfff orthosis are presented- The results of these evaIuations
are ordered from the most Quantitath methodologies, which measure user output, to the most qualitative
methodologies, which solicit user input F M , the results oftbe ciinical assessment, which sought to
uncover clinical indicators and/or contraindicators for success with Toeoff- are presented
4.1 Participants
Skqeen individuals volunteered to trial the Toeoff orthosis; demographic characteristics are
summarized in Table 4.1. Ofthe 16 volunteers, three were unable to wear the orthosis- One individual
experienced emcme pain in her toes? and a second was assessed as unsafe at the h e of his fitting- Both
these individuals eqerience ankle and foot spasticity, A third subject who had footdrop resulting fiom
multiple sclerosis was unable to wear the ToeOff orthosis, and is no longer wearing any orthosis, Using
her very limited muscle strength, this individual had likeiy made accomodations to her gait which could
not be performed when wearing any orthosis- Two other subjects voluntarily withdrew from the project,
for reasons unrelated to orthosis function The remaining eieven subjects completed initial testing (PCI,
Acme) wit11 their original orthosis, were fitted with the ToeOff orthosis, and compIeted retesting (PCI,
ActRe) after an accommodation period of one to four weeks.
Of the 11 individuals who haled Toeoff, LO had an original tl~ennoplastic hinged AFO (see
Figure A. I in Appendix A), wlule the individual with a back injury had an originaf plantarflexion assist
AFO (see Figure A2 in Appendix A).
Fitting took place at the Prosthetics k Orthotics Clinic at StMary's of the Lake in Kingston,
Ontario. All individuals had obtained their original orthosis tluough this same clinic, except one
participant, who had obtained his original orthosis at Chedoke McMaster Hospital in Hamilton-
Individuals were monitored by telephone during the accomodation period, and appointments were made
for modifications and adjustments as necessaryeceSSary Once rhe individual felt he or she had adjusted to the
ToeOfForthosis, retesting was scheduled. Focos groups of24 were scheduled once each
participant had uided the ToeOfForthosis for at least two weeks- Individuals who were unable to wear
the ToeOff onhosis were also invited to parkipate in a focus group- One individual who had trialed
ToeO£F was unable to +ame in a focus group due to hospitaihtion In total, 12 individuals
participated in a focus group d h w i o n ,
Table 4.1 Description of Participants
S6 is now \.-ring a greatly modified ToeOff w*th the foot plate cut off and replaced with a flexible sole- The spasticity in her toes mused her considerable pain with the original -foot plate, but
0.
she is very happy with this m m e d version
0.0
S 12 lus now recovered sufficient firnction to walk without an orthosis
0m.m
S 14 found neither orthosis l~elpfd, and is no Ionger using any AFO S 16 is attempting to make the sole plate more rigid
-
Compkted PCI
Y Y I
#
S1 S2 S3
S4 SS S6
S7
, S8 S9 SIO SI1 S12
S13 S14
S1S S16
Gender
F M M
F F F
F M M .
F F M
M F
M M
Age
55 52 62
57 ,
52 76
73 70 73 43 57 17
58 55
65 52
Completed
Croup Y Y
Diagnosis
Stroke Stroke Stroke
Stroke Stroke Stroke
Stroke Stroke Stroke Stroke Stroke
Peroneal newopathy
Stroke MS
Stroke BackInjury
Still
Toeoff Y Y N
N Y N'
N/A N Y Y Y No*
N/A N-'*
Y N- ~-
Unable to wear
Y Y -
Unable to wear
Withdrew Y Y Y Y Y
Withdrew Unable to wear
Y Y
Dateof Onset
9/95 1 I/% 16/93
8/92 1U96 1/93
12/95 6/96 2/95 3/95 11192 1/98
8/93 1989
9/98 I985
T
Y
Y Y Y
Withdrew Y Y Y Y Y
Withdrew N
N Y
Sideof Orthosis
R L R
L R
P-ous AFO
Hinged Hinged Solid
Hinged Hinged
R
L R L R L L
L L
L R
Hinged
Hinged Hinged Hinged Hinged Winged Hinged
NDT brace Hinged
Hinged Hinged
(anterior)
4.2 Gait Analysis
A 1I I gait analysis was performed on two individuals, one who demonstrated positive PC1 results
with ToeOK and one who demonstrated negative PC1 results with ToeOff (see section 4.3.1 for
eiilanation of PC1 results), ResuIts of the gait anaIyses are presented in a case study fonnat in
Appendices I and J, and are summarized below- While a £U analysis is presented in the appendices. the
following summary emphasizes kinematics and kinetics occurring at the ankle- To assist the reader, an
overview of normal power pro£iIes during gait is presented in Appendix H, and profiles of healthy adults
walking at M a r speeds are supeximposed on all graphs found in the appendices (Winter, 1991).
4.2.1 Summary of Case Study #1
The first study (Appendix I) involved an individual (Sl) who demonmated an increase in
energy cost, in terms of PC1 resuits (see seaion 4.3-1 for explanation of PC1 resuIts), when wearing the
ToeOff AFO compared to her original orthosis- Powers (W/kg) across the ankle, knee and hip joints were
calculated for tluee strides on each side with each AFO, and maximum and minimum values at selected
phases of the gait cycle are reported in Table 4-2, Profiles ofjoint powers with the original and ToeOff
AFOs are presented in Figures 4-1 and 4.2 respectively. Power absorption (Al) and generation (A2) at
the ankle was greater on the afllected side with the original AFO, but greater on the unafiiected side with
ToeOff. Ankle power profiles showed near nonnal power generation (A2) with the original AFO, but
vaIues below n o d with ToeOK For the wrairited side, power generation at the ankle was above
normal with both orthoses. but considerably greater than n o d with Tm Power absorption at the
unaffected ankle (Al) \as slightly greater than normal on both sides and with both orthoses, although the
increase was most pronounced with
Unaffected Side 1 1 Affected Side I
HIP
I
KNEE 3.0 I
!
ANKLE 6.0 - 1
-2.0 I 0 10 20 30 40 50 60 70 80 90 1W
PERCENT OF GAIT CYCLE ("3)
3.0 5
HIP
i I
KNEE
3-0 o
ANKLE
6-a /
-2.0 ' 1
0 10 30 40 50 60 70 80 90100 PERCENT OF GAIT CYCLE (%)
-
Figure 4.1 Joint Power Profiles (Wlkg) of the Hip, Knee, and Ankle Joint of S1 -
for three trials when walking with original AFO (thin lines) compared to healthy adults walking at a similar speed (thick line)
I Unaffected Side I Affected Side I HIP 3.0 1
HIP 3.0 1
KNEE KNEE
0 10 20 30 40 50 60 70 80 90100 0 10 20 30 40 50 60 70 80 90100
0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0 0 1 0 a O 3 0 4 0 s O 6 0 7 0 8 0 ~ ~ 0 0 PERCENT OF GAIT CYCLE (%I PERCENT OF GAIT CYCLE (O/o)
Figure 4.2 Joint Power Profiles (Wlkg) of the Hip, Knee, and Ankle Joint of 81 for three trials when walking with ToeOff AFO (thin lines) compared to healthy adults walking at a similar speed (thick line)
Table 4.2 Peak Powers (Wlkg) of the Ankle, Knee and Hip Joints for S1
4.2.2 Summary of Case Study #2
The second case study (Appendix J) i n v o I d an individual (S 16) who demonstrated positive
energy savings, in terms of PC1 results (see section 4.3- 1 for esplanation of PC1 resuits), when wearing the
ToeOff AFO compared to his original orthosis- Powers (Wtkg) across the ankle, knee and hip joints were
averaged over thee strides on each side with each AFO, and ~llauimum and minimum values at selected
phases of the gait cycle are reported in Table 4.3, Profiles ofjoint powers wit11 the original and ToeOff
AFOs are presented in Figures 4.3 and 4-4 respectively, Power absorption at the ankle (Al) was greater
with ToeOff on both sides. Power generation at the ankle (A2) was greater on the atllected side with the
original AFO, but greater on the unnffected side with Tm Ankle power profiles showed a decrease in
power generation of t l~e aaFected side at push-off CAZ), which was simiIar in degree with both orthoses.
For the unafkcted side, average power generation at the ankle was bdow normal with the original
Variables
Ankle Mkx (A2): generation Ankle Min (Al) over Stride: absorption Ankle Range over Stride Knee Mas over Stride Knee Max (K2)r generation Knee Min over Stride Knee Range over Stride Hip Max over Stride Hip Mas (Hl) over Stance: generation Hip Min (H2): absorption Hip Max (H3) at pull=& generation Hip Range over Stride
orthosis. but greater than normal with ToeOE Power absorption at the ankle (Al) was slightly greater
than normal on both sides and with both orthoses, although the increase was most pronounced with
Toeoff-
A f f ' e d Side Original
AFO 1-90
Unaf&ted Side T d f f AFO 1.36
-1.06 2-96 032 0.32 4-82 1-14 0.97 0-95 -0.58 0-97 1-35
Original AFO .
2-85
T o m AFO 4.09 01-77 5-86 0.74 0-3 1
4-95 f -1-06 2.3 1 0.42
3-91 0-46
4-61 1.03 0-76 0-76 4.47 0.69 1.23
0.09 -2-02 1 02-34 0-09
2-88 1-21
3 -08 2.10
0-71 I 1.3 4-49 1-21 1-70
4-70 2-10 2-80
I , AMcted side] I 1 Unaffected Side 1
------------------------
0 lo 20 30 40 50 60 70 80 90 100 11 10 20 30 40 50 70 80 90 100 L
KNEE KNEE
Figure 4.4 Joint Power Profiles (Wlkg) of the Hip, Knee, and Ankle Joint of S16 for three strides when walking with original AFO (thin lines) compared to healthy adults walking at a similar speed (thick line)
2.0 , HIP
I
Affected side1
KNEE 3.0 , i
I Unaffected Side 1
ANKLE 6-0
0 10 20 30 40 50 60 70 80 90 100 PERCENT OF GNTCYCLE (%)
2.0 -, HIP
KNEE 3.0 1 I
ANKLE 6.0 1 I
0 10 20 30 40 50 60 70 80 90100 PERCENT OF GAIT CYCLE ('36)
Figure 4.5 Joint Power Profiles (Wlkg) of the Hip, Knee, and Ankle Joint of 516 for three strides when walking with ToeOff AFO (thin tines) compared to healthy adults walking at a similar speed (thick line)
Table 4.3 Peak Powers (Wlkg) of the Ankle, Knee and Hip Joints for S16
Variables AfCicd Side I UnPtCected Side
I
original 1 TaOIT ( Original ( TaO(f
Ankle Max (A2): peneration Ankle Mia (Al) over Stride: absorption Ankle Range over Stn*de Knee Max over Stride Knee Max (K2): ene era ti on Knee Min over Stride Knee Range over Stride Hip M%x over Stride Hip Max CHI) over Stance: generation
Work (Jkg) across the ankle, knee, and hip joints were acquired for three strides on each side
with each AFO, and mean values for selected events of the gait cycIe are reported in Table 4-4. Positive
Hip MIn (H2): absorption Hip Max (H3) at pullloff: generation
Range over Stride
work at the ankle joint (A2) was very. similar with the two orthoses on both sides. Positive work at the
knee and hip joints were identical with both ortlioses on the affected side, while positive work at tlie knee
joint (K2) was higher on the d e c t e d side with Toeof& and positive work at the hip joint (H3 only) was
higher on the u d e t t e d tide with ToeOK
AFO 1.09 4-65 1-74 1.61 0-79 -3.53 5, 14 1-18 1-18
Table 4.4 Work (Jlkg) at the Ankle, Knee, and Hip Joints for S16
4-21 0-7 1 1-40
AFO 0.83 -1.34 4-75 1.32 0.94 -3.45 4-77 0-98 0-79 4-79 0.94 1-77
Variables
Ankle (A2) Positive Knee (Kl) Negative Knee (K2) Positive Knee (K3) Negative Knee (K4) Negative Hip (Hl) Positive Hip (H2) Negative Hip (H3) Positive
AFO 2.67 -0.85 3.53
AFO 3 -40 -1.35 4-75
4-55 0.60 1-21
43-79 0.94 1-77
Affected Side
0-59 0.37 -2.75 3.34 0.67 0.59
Unafkted Side Original AFO 0.06 0.32 0.08 0.18 0.12 022 0.02 0.13
1.32 0.94 -3 -45 4-77 098 0-79
Original AFO 0.25 0.27 0-03 0.27 0-12 0.14 0.08 0.06
Toeoff AFO 0.04 0, I6 0.08 0.20 0.13 0.22 0.02 0-13
Toeoff AFO 0.27 0.26 0-10
I
0.35 0-16 0.14 0.11 0-12
1
4.3 Walking Tests
4.3.1 Physiological Cost Index
The physiological cost index (PC0 was evaluated at seLf-selected comfortable and fast walking
speeds. The d t s for each speed are reported in Tables 4-12 and 4-13 respectively, and displayed
graphically in Figures 4- 13 and 4.14, In interpreting the PC1 results, a change of 10% in either PC1 or
walking speed was interpreted as clinically significant (Olney, 1999)-
4.3.1.1 PC1 Results at Self-selected Comfortable Walking Speeds
At self-selected comfortable walking speeds, mean change in PC1 was -10.53%
(*27.66), wluIe their mean change in waking speed was +3.62 (*10.82), when walking with the ToeOff
AFO compared to their original AFO. Univariate totests of mean comfortable walking speed (p0.19) and
mean PC1 at comfortable walking speed @=0.13) were not statistidy significant, which indicates that
group results with each of the two orthoses were not statistidy dBerent,
Looking at individual results, however. sis participants showed unequivocally positive
improvements when wearing the ToeOff orthosis. Participants S4, S12 and Sl6 showed the most notable
savings in energy eqtenditure. These three participants waked at strikingly faster velocities with T o e
(+17%, +15%, +13%), and also showed a decrease in physiological cost (-19% -120/a, -1 1%). Subjects 5,
9 and 11 walked at similar speeds with both orthoses, but showed a decrease in physiological cost (40% - S 1% -51%) when wearing T-
One individual showed probable gains when walking with the ToeOff orthosis at a self-selected
comfortable speed. Subject 15 was able to walk remarkably fmer (+19./0) wiih the ToeOEorthosis, but
showed a corresponding increase in PC1 (+lS%)). Thk likely represents a positive result, since the
individual was able to achieve a faster walking speed and supported the increase in physiological cost,
Using a change of 10°h as cIiaicaUy significant, subject 10 showed no merence in PC1 or
walking speed between the two orthoses, when walking at a seK-selected comfortable speed Finally, three
individuals (Sl, S2, SS) did not show any ofthe predicted gains at this speed. In these cases
walked at the same speed or more slowly with ToeOEand their physiological cost ofwaking was higher.
Table 4.12 PC1 at Self-Selected Comfortable Walking Speeds
#
S1 S2 st S5 sa S9 S 10 Sll S 12 S 1s S 16
I Original
AFO 0.54 0.51 0.90 0.68 0.42 0.73 0.7 1 0.L1 0.5 1 0.53 0.37
AFO 0.63 0-57 0-73 0-41 0-51 0.36 0-75 0-05 0-45 0.6 1 0-33
re'
I I
I
L *A
Difference +16,67 +L 1-76 48-89 -39.71 +2 1-43 -50.68 +5,63 -51.55 -I 1-76 +15.09 -10.81
S] Origiad
AFO 57-11 6s- 14 46-48 45-72 21.43 27-46 49.05 38.02 69.17 24.59 78.37
1)
O h
Difference -525
-1 1-30 +17-43 -5- 12 +1S4 +0S8 -7.8 1 +2-63 +14-75 +lg,ll +I3 -27
Table 4.1 3 PCI at Self-Selected Fast Walking Speeds
I OriginaJ AFO 0.59 0.82 0.99 0.59 0.38 0.58 0.78 0.13 0.77 0.62 0.55
31 (beatdmetl ToeOff AFO 0-67 0.73 1-10 0.48 0.42 0-56 0-68 0-16 0.64 0A2 0.32
47.50 18-78
Mean SD
1 Yo
Difference t13.56 -10.98 +11,11 -18.64 +10.53 -3 -45 -12.82 +23 -08 -16.88 -32.26 -23 -64
0.55 0.21
0-49 0.20
S] Original AFO 63-13 75-70 52.68 45-72 29.29 30-79 51-08 45.05 89.43 24.09 103.49
49.17 20-9 1
-10.53 27.66
+3 -62 10-82
, Mean SD
0.62 0.23
0.57 0.21
6-49 17.74
+4.83 17-80
55.50 25.37
57.27 25.65
4.3.1 -2 PC1 Results at Self-selected Fast Walking Speeds
At self-selected fast waIking speeds, participants' mean change in PC1 was -5-49?h W7-741,
while their mean change in walking speed was +4.83 (*17,80), when walking with Toeoffcompared to
their original AFO. A univariate t-test of mean fist walking speed with each of the two orthoses was not
statistically significant w.18) ; the llnivariate t-test of mean PC1 at fbt walldng speed approached
statistical significance @=0.07), Tlris indicates that group results with each of the two orthoses were not
statistically different, although a trend towards lower PC1 at fast walldng speed was shown,
Although there was no average difference in PCI or walking speed, s ix individuals showed
unequivocally positive improvements when wearing the Teorthosis . Subject 15 showed the most
notable energy savings, with a 47% Increase in walking speed and a 32% decrease in PCL Subjects 2,s-
10, 12 and 16 walked at simiIar speeds but showed a decrease in PC1 (-1 1% -19% -13% -17% -24%)-
Two individuals showed probable gains when walking with the ToeOff orthosis at ~e~se l ec t ed
fast speeds. Subject 1 maintained an increased waiking speed (+l6%) with an 11% increase in PCI,
Subject 1 I displayed a remarkable increase in walking speed (+2 1%) but showed a corresponding
increase in PC1 (+23%), These results are likely positive, since both individuals were able to achieve
faster walking speeds and supported the increase in physiologid cost
At self-selected fast speeds, one individual (S9) showed comparable results with each
AFO. and two individuals (S 1, S8) did not show any of the predicted gains- In these two cases
participants waked more slowiy with ToeOff and their physiological cost of walking was higher,
Note that for two individuals (S5. SIS), their slf&lected f a waking speed was identical to
their ~e~se l ec t ed comfortable waIking speed When asked to cover as much ground as possiile in six
minutes. these two participants walked at the same average speed as when asked to walk at their normal,
comfortable walking pace. This clearly indicates that these two individuals had limited capabilities to
increase their walking speed above their comfortable walking pace,
4.3.1.3 Summary of PC1 Results
Group results indicate that there was no average diEcrence in walking speed or PC1 with each of
the two orthoses, although a trend towards lower PCI with ToeOffat fast waking speeds was shorn At
self-seIected comfortable walking speeds, slx mduaIs (a, SS, S9, Sf 1, S12, S16) showed
unequivocally positive improvements and one individual (S 15) showed probable improvement, when
wearing the ToeOfforthosis. Of the seven partlkipants who showed gains or probable gains at
comfonabIe waking speeds, results were dso positive or probably positive at seKseI~ed fast speeds,
with the exception of one person (S9), who showed no difference between orthoses at the m e r walking
speed- Furtllermore, two individuals (S2, SIO) who did not show improvements at self-selected
comfortable speeds demonstrated gains at self-selected fsst waking speeds, Two participants (Sl, S8)
demonstrated negative PC1 r d t s with ToeOffat both walking speedsspeeds
Figure 4.1 3 Physiological Cost index at Salt-Selected Comfort.ble Walking Speeds Wearing Original AFO (smalt symbols) and 1- AFO (large symbols)
Figure 4.1 4 Physiological Cost Index at SekSeIected Fast Walking Speeds Wearing Original AFO (small symbols) and T d f f AFO (large symbols)
4.3.2 Six-Minute Walking Test
An AFO which returns energy to the user may allow a Ester walking s p e d The six-minute
waking test evaluated the distance that tach individual was a& to cover in six mlrmtes, when walking as
fast as was comfortabIe with each orthosis- Results are summarized in TabIe 4- 14.
Table 4.14 Six-Minute Walking Test Results
Subject Number
SI S2 st ss S8 S9
S I0 S11 S 12 SIS
Original AFO 378
Participants' mean merence in the distance covered in sis minutes was +4.8 (*17,8), when
Mean S td,Dev.
wearing the ToeOff AFO compared to the original AFO. A univariate t-test on the distance walked found
no statistical difference between onhoses (@-1%). Although there was no average difference in the
333 152
distance walked, four individuals (St. S L 1, S 12, S 15) covered a greater distance when wearing the ToeOBI
AFO. For three of these four partkipants, the gains were notably large- Five individuals waked
comparable distances with the two orthoses, while two individuals (Sl, S8) showed a decrease in the
distance walkecL
344 154
+4,8 17.8
4.3.3 Summary of Walking Test Results
There w a s no statistical difTerence in PCI, walking speed, or distance walked between the two
orthoses, atthough a trend towards lower PC1 at fast waking speed was shown @=O-Of), Although the
group results are indicative of no diffkrence: between orthoses, individual d t s are clinically important,
Combining the PC1 and six-minute walkjng test results, seven participants (S4, SS, S9, S 11, S 12, S 15,
S 16) showed gains or probable gains when wearing the ToeOfforchosis- Four of these individuals (S4,
S 1 1. S 12. S IS) were able to increase the distance ~mUred in sis minutes, when wearing T- One
participant (SIO) showed no red change with the ToeOEorthosis, while another (S2) showed slightfy
negative PC1 results at self-selected comfortable speeds, but a slight improvement at self4eiected fast
speeds. Thus this second individual, whose di@erences were just above the 10% change deemed cIin.icaIly
significant. can also be interpreted as demonstrating no real change. Two individuaIs (S 1, S8)
demonstrated negative PC1 results at both self-selected comfortable and fast walking speeds, as we11 as a
decrease in the distance walked during the sis-minute walking test, when wearing To--
4.4 Activity Record
In completing the Activity Record (Act&), participants reported the main activity they were
engaged in during each half-hour of hvo consecutive weekdays- Participants also assigned each half-hour
period to the activity category of best fit, selecting among categories of rest, self-care, preparation or
planning. household activities, work, recreation or leisure, transportation, treatment, and sleep (Appendix
E). Involving participants in the coding process provides more valid category assignments- For example,
watching television may at times be a fonn of recreation and leisure, while at others it provides a needed
rest break.
ActRe results were processed and the mean percentage of waking time in each activity category
determined. Tests of skewness, kurtosis, and normality were performed to assess the normality of each
variable's distribution, Where appropriate, transformations were made to improve the normality of
distri'butions before performing multivariate and univariate t-tests- Mean values reported here were
calculated from the raw data, bowever p values were obtained from tests pcrfofmed on traasformcd data,
where appropriate-
It was expected that participants wouId be more active andfor less ktigued in a typical &y, when
wearing the ToeOff AFO compared to their original orthosis- Two multivariate t-tests were performed on
variables related to rest and fatigue respectively. A multi-ate t-test on the mean percentage of time
spent in rest and sleep was statistically significant @=-005), while a multivariate t-test on the mean
percentage of time spent in fatigue7 in activities causing fitigue, and in pain was not statistidy
signifxcant (p=O, 1 I),
Table 4-15 reports the mean percentage ofwaking time spent in each activity category, as well as
the associated p values fiom one-tailed univariate t-tests- Participants significantly decreased the mean
percentage of waking time spent resting as a main activity @=.032), when wearing the ToeOfforthosis-
On average. 123% of participants' waking time was spent resting when wearing their original AFO,
compared to 6-8% of waking time with Tm This suggests that participants were able to increase time
spent in other activity categories, when wearing T d f f compared to their origiaal AFO. A multivariate
t-test on the mean percentage of waking time spent in activity categories other than rest or sleep
approached statistical significance @=.083). Paired t-tests on the mean percentage of waking time spent
in these activity categories found a statistically significant increase in participation in recreation and
leisure activities only (p=.024). When wearing their original AFO, participants spent an average 333%
of waking time in recreation and leisure activities, compared to 395% with ToeCE There was also a
trend toward increased participation in self-care activities when wearing ToeOff; &though this result did
not attain statistical signif~cance @=.074).
Table 4.1 5 Mean Percentage of Waking time By Activity Category
Activity Categorg
Rest Household Activities Work Self-care Recreation & Leisure Preparation & Planning Traosportation Treatment
Mean Percmttg Original AFO
12.5 14.5 6.1 20.3 33.5 1.3 6.0 3.7
Table 4.16 Mean Percentage of Time Spent in Sleep, Rest, and Physical Activity
I Activity Category I Mean Pementi I
(as a nuin activity)
(during physicaI activity) PIwsical Activi
Sleep
age of Time* Toeoff AFO
39.1 6.82
Original AFO 35.3
P value
1 23 -6 I -1 13 *activity categories are not mutually exclusive or esimstive. and columns will not total 100%
Table 4.17 Mean Percentage of Waking Time Spent in Pain, Fatigue &
The mean percentage oftime spent in sleep, and the mean percentage ofwaking time spcnt
resting and physically active are reported in Table 4.16. As noted above, participants significantly
decreased the mean percentage of time spent resting as a main activity @=.032). when wearing TaeOff
Wearing AFO P value
-136 -297 - 174 .O2l*
Activity Category
Esqeriencing Pain Eqeriencing Fatigue Activity Causes Fatigue Wearing AFO *activity categories are not mutually esclusive or exhaustive, and columns will not total 100%
M a n Percentage of Waking Time* Original AFO
21.5 24.5 23.4 67.6
TocOff Al?O 17-0 27.1 32.3 79.3
compared to their original AFO- However, participants also slightly increased ?he mean percentage of
time spent asleep W O O 1)- On average, participants were asleep 35.3% of a tppicaL 2-day period when
wearing their ori- AFO, compared to 39,1% with ToeOff- This result is di8Eicult to interpret, since a
significant increase in the time spent sleeping may indicate that participants were able to get a better
night's sleep. when wearing ToeOff, or that tiley were more active when wearing Toe04 and therefore
required more sleep-
The ActRe defines physical activity as "standing walking, liftiag or moving around." Overall,
there was no significant difference in the mean number of rest penpenads requited during physical activity, or
in the mean percentage of waking time spent physically active (Table 4-16). Figure 4. IS displays the
mean percentage of waking time spent in physical activity for each of the I1 participants, when wearing
each ortl~osis, Looking at these individual results, 6 participants increased their physical activity levels, 2
showed no change. and 3 decreased their physical activity, when wearing ToeOK In general these results
are consistent with measures of physioIogica1 cost, that is, individuals who sho\ved a decrease in energy
cost when wearing Toeoffwere able to increase their physical activity during a typical day, and vice
versa.
Table 4-17 reports the mean percentage of tvaking time spent in pain, fatigue, activities causing
fatigue and wearing each AFO, as well as the associated p values fiom one-taiIed univariate t-tests.
Overaii, there was no significant difference in the mean percentage of waking time spent in pain or
fatigue, or in the mean percentage of waking time for which activities were reported as causing fatigue.
TIuee individuals had a marked decrease in the percentage of waking time spent in pain, while two had a
marked increase in pain, when wearing Toeoff- Note that these individual Merences may represent
changes in pain leveIs due to other health conditions unrelated to the type of orthosis in use. In terms of
fatigue, two individuals showed a decrease in fatigue and six showed an increase in fhtigue, when wearing
ToeOfE However, participants also reported an increase in activities causing fatigue; three individuals
reported a decrease in fatigue causing activities while six reported an increase in these activities, when
wearing ToeOfFcompared to their originally prescribed MU.
Figure 4.16 Mean Percentage of Waking Time Spent in Physical Activity
Original ToeOff 1
S I S2 S4 S5 S8 S9 S70 S11 ST2 Sf5 S16
Subject Number
A one-tailed univariate paired t-test was performed on AFO usage time- In U cases, usage time
of the ToeOff orthosis was either similar to or greater than that of the original AFO (Table 4-17). The
mean percentage of time spent wearing T d f f was statisticaiIy greater than that wearing the original
AFO w--021).
4.5 Questionnaires
The 11 participants who triaied the ToeOff AFO completed noncomparative and comparative
rating scales- One participant couid not use stairs, and therefore did not rate the two orthoses on this
dimension-
4.5.1 Noncomparative Rating Scales
Prior to the six-minute walks with each orthosis, participants completed a noncomparative raring
form which ranked dimensions related to comfort, function, appearance and application on a Liken scaIe
from 0 to 4 (Appendk F). It was expected that participants would indicated higher ratings for the Toem
orthosis; actual ratings are summarized in Table 4.18.
Table 4.18 Noncomparative Ratings of Original and ToeOff Orthoses - 7 Noncomparativc ukert Ratings (04)
Comfort
Even Ground -
Uneven Ground
Up Stairs
Down Stairs
Overall Function
Appearance
Application
OveraJi
Orthosis Type
Original ToeOff
Original Toeoff
Original ToeQE Original ToeOff Original Toeoff Original ToeOff
Original ToeOff
Original Toeoff Original
- ~ w o f f - -
Mean
2.36 3-18 2.82 3 -09 2.55 2.36 2.56
Median
2 3 3 3 3 3 3
Standard
1.03 -60 -87 -83 -82 -8 1 1-01
2.56 2.22 2.67 2-73 3 -00 2.09 2.55 2.70 2.50 2.82 3 -00
P value
.036*
-294
-24
-88 -97 -7 L -65 -77 1-14 1-13 -67 1.35
- -60 -77-
3 3 3 3 3 2 3 3
2.5 3 3
,446
,128
,204
,176
-416
,304
In terms of comfort, walking onevea ground, going down stairs, overall firnction, appearaace?
and overdl rating the mean Likert Scale rating was higher for the ToeOfforthosis than the original
ortI~osis. For waking on uneven ground and appiication, the mean Likert scale rating was higher for the
originaI orthosis than the T ~ o r t h o s i s o s i s Note that of the one-tailed p values presented in Table 4-18,
the values for walking on uneven ground and application relate to the probabiIity ofa higher median
rating for the original otthosis, while all other p values relate to the probability of a higher median rating
for the ToeOff orthon's-
The Wiicoxon Signed Ranks Test was used to test the probability of a higher median rating for
the ToeOff orthosis, Results indicate that the 1 1 participants rated the ToeOEorthosis significantly
lugher than their original orthosis, in terms of comfort p.036)- For the chosen alpha level (p=-05), the
median rating of the ToeOEorthosis was not statistically diffierent from that of the original orthosis on
any of the other dimensions examined
4.5.2 Comparative Rating Scales
After having had both AFOs for at least two months, participants verbally completed a
comparative rating scale (Appendix F) indicating a preference for one of their two orthoses, or no
preference, on dimensions related to comfort, hction, appearance, and application, It w a s e-vpected that
participants would indicate a preference for the ToeOfforthosis; actual comparative ratings are reported
in Table 3-19.
In terms of comfort, walking on even ground, going up stairs, appearance, and overall rating
more participants indicated a preference for the ToeOgorthosis. For walking on uneven ground and
going down stairs, more participants indicated a preference for their original AFO- For overall fbction
and application, almost the same nuder of participants preferred each orthosis.
Table 4.1 9 Comparative Ratings of Original and ToeOff Orthoses
* Probability that preference for the ToeOff AFO, among who expressed a preference for one of tlre two orthoses, is not statisticaiIy diflrerent than 50%
The one-taiIed p value presented in TabIe 3- 19 represents the probability that preferen~e for the
ToeOff AFO, among participants who eqressed a preference for one of the two orthoses, is not
P value* 1 -0625 1 -0625 1 -774 1 -344 1 -656 1 5 1 -09 1 -5 1 254 1
Applic- ation
2
5
4
statisticaily different tlm 50%. The binomial test was used to evaluate the probability of preference for
the ToeOff orthosis. For the chosen alpba level @=.05), the probability of preference for the ToeOff AFO
was not statistically different than 50% on any of the dimensions tested. Statistical significance was
Overalld
2
3
6
Donn Stairs
4
4
2
Preference
None
original AFO
ToeOtfAFO
approached on thee dimensions, however, with a trend towards preference for TaeOB in terms of comfort
Even Ground
4
1
6
ComfoH
4
6
(p=.0625), walking on even ground @=.0625), and appearance @--09).
O v e d Function
2
4
5
4.6 Focus Groups
Four f m groups were held, using a predetermined interview guide (Appendix G) whicli
esplored topics offimction, comfort, appearance and application- The predominant themes which
emerged within each topic area and throughout the discussions are summarized here. Each focus group
transcript rvfas coded in test units and assigned to themes which arose fiom the text itseK Following each
cited quotation, the focus group and coded tex~ unit number are identified in parentheses. For esample,
"FG#1.208" identifies tesq unit 208 fiom the £irst focus group transcript, Where dialogue between two or
more participants is presented, speakers axe identified by capital Ietters.
The purpose of the h t ffocu p u p question (Appendix G) was to allow participants to identifL
clmracteristics of AFOs which are important to them by descniing the instnrctions they would give to a
designer hired to make an orthosis specifically for them. In general, it was ddficult for partrkipants to
Appear- ance
2
2
7
Uneven Ground
4
5
2
Up Stairs
4
2
4
discuss the abstract concept of the ideal AFO, and the discusdon quickly focussed on specific
characteristics of the two AFOs participants had worn, Appropriate colour, fit, weight, and cost, as weIl
as ease of application, were identified by participants as important issues, These topics had already been
incorporated into the predetermined interview guide; and were explored as each issue arose.
Except for the lf-year old mak, all participants activeLy contnied to the discussiom Some
people already knew each other fiom a stroke support group, however wen those who had not met
previously easily related with each other and were interested in what others had to say- OAen participants
asked each other questions a b u t their diagnoses and esperiences, or how they ~nanageci certain tasks:
Well this is what I like about meeting people that have got the same thing is you all know what's wrong.-.. you know, it is nice to know that it's not just you that has got this (FG#l, 5-7)-
Let me use tI~s one first [to demonstrate putting AFO on], 'cause maybe you've got more e-sperience than I have, and maybe I'm not doing it right, maybe there's some technique that I don't know about (FG#2,7 18-720)-
Participants were happy to share thoughts and ideas, and provided concrete esamples of their
daily experience with the two AFOs.
Results Imve been organized into six topic areas: social context, the four topic areas directly
addressed in the focus group interview guide (hction, comfort, appearance and application), and
recommendations. Each topic area is subdivided into the themes that emerged within that topic,
4.6.1 Social Context
Although the primary objective of the focus groups was to solicit feedback about the AIOs worn
by participants, quditative research provides direct feedback which is framed by individual esperience.
That is, individuals commented not only on AFO clwacteristics, but also on using an AFO within the
context of their lives and disability:
I tlunk if it was more of a skin tone, for women anyway it would, you'd feel more comfortable. Especially I'm trying not to let my disability get to me.,.. I'm going around like as if I was normai, and.., I don't want to advertise my disability, I mean to some people obviously I just walk into a restaurant and they know it because, because of your
arm, the way it just sits there Like a bump on a log.,, but um, I find if I really want to dress up, the black would show through a lot of my cIothes uh because they're a Light shade (FG#L, 301)-
Assistive devices have peoUsiy been identified as symbols of disability, Use of a cane, for example,
brings with it ass0claSSOClated meanings ofage and disability (Aminzadeh & Edwards, 1998)- Vib le asktive
devices publicly identi@ a physical limitation, and are undesirable to some people because they are a
concrete representation of difference fiom the norm, The following four quotes were made by three
women for whom the most desirable device is the least noticeable devicet the one which can be hidden
most easily, and the one with which they feei most 'normal' or least di8lerenc
I only just started to wear shorts, before then I said oh I can't wear shorts,,.-- well they say so, what's wrong with you, you know.., but with this [original AFO] I can because it doesn't show so much I suppose...c with this roeoff AFO] I suppose being a woman everybody would look, 'Black what's she got there.' you know. .. so I think it's a pity they thought of black,,, (FG#l, 208)
If you wear something like that you think 'Oh I have to wear dark trousers today,' you know we're putting ourselves in a different category again, You want to be nonnal, you want to be as you were or as near as you were or as near as the woman next door is, so you don't want anything that's going to make you be Merent (FG#l, 1788)-
I have set my mind fiom the fim day I started to wear a brace no matter which one I'm wearhg.,-.----that I will not be seen in anything else but trousers.,. I won't even try a dress on,-,,- I have set, like I have my mind set that you won't ever see me in a dress while I'm wearing a brace-.., (FG#l, 328)
Well, the advantage I think of the look of it [ToeOff AFO] is, you put on a shoe, you can wear a long dress, and if you're going to dance or something like that, something thatlU show the heel, you don't see a heel with the black one, so the shae looks better (FG#4, 697).
For other persons. in this case nvo men, visibility of the AFO was not a concern:
A: Hell, I've got a gimpy leg, I don't mind if somebody sees I'm wearing a brace paugls], I don't, do you find it bothers you?
4.6-2 Function
Ankle Support
From a user's perspective, the primary differentiator between the two orthoscs was not the spring
effect of the ToeOfFsole plate, but the difference in ankle support, Most people commented that the
ToeOff AFO provides noticeab1y less &e support, For some individuaIs this was not a problem, but five
participants felt less secure when walking on uneven gmund with TaOfE
I found that this VoeOE AFO] was a htastic support for my ankle, htastic (FG#l, 593)
Your other candidate, we won't mention names, but urn she got the same feeling L did at the beginning, Like as if she didn't like, as if her ankle was gonna, like when I wasn't m - n g the teds stockings I felt like my ankle was gonna m*st [with Toeoff AFO] (FGiYl, 983)
C: When I walk outside, on the ground, I always take my cane with me, because, I don't know I guess maybe that's what it is, I just don't feel like I have enough support there [at the ankie] ,-- I can wear tlk one [original AFO] and I'm not a bit nervous, but if I'm walking with the black one on I take my cane (FG#, 1060)
D: 'C' you said when you go outside with the black brace you take your cane, what about if you're walkkg in the hail or in a mall somewhere?
C: No I'm fine with that, it's just the uneven ground, and I think it's all in my mind really, cause I can wear this [original AFO] it doesn't bother me at aU (FG#4, 1 151- 1 151)
One individual used her original AFO exclusively when perfomcd gardening work, and one
individual used a cane when walking outside with ToeOc but not with her original AFO. Other
individuals who felt less secure walking on uneven ground with ToeOff did not avoid or m e
this activity, but walked more slowly and carefUy when wearing ToeOK
Ankle Movement
Due to the decrease in ankle support, ToeOff alIows more natural movement at the ankle. This
nas noted as beneficial by four participants:
I had the feeling that this brace [original AFO] encased my foot and my ankle, so that I didn't get any muscle development around my ankle as long as I was wearing that brace- This one Foeoff AFOJ your ankles are m y , not, are free, and I think this probably does a better job developing your ankle muscle (FG#2,520)
Ar 1 found the first couple of weeks wearing the new one, rhe T o e the muscles in my calves were finally stretching and ilI teII you it was sore-.-
Br So you were getting more of a workout there?
A: Yup. Whereas there mints to original AFO] you got really no place for any flesiiility @G#3,676483)
C: I won't go back to that one [original AFO] anymore because it made my uh ankle fiozen so..- you have to walk on the ball of your feet, start on your heel and go to your toe. and you can't do it in that thing
D: No you can't do it in tlus [original AFO], you're flat footed
C: And my ankle got fkzen, I don't know the word for it, but I have to stretch it now all the time
A: Well your ankle has atrophied, mine has too, but 1 found since putting the ToeOff on, I'm stretching it out (FG#3, 162801638)
Walking
Most individuals noticed a Werence in the way they walked with each orthosis, and were able to
provide clear e.uampIes of differences they had noted- Most individuds found that they walked more
A: ... yow gait seems to be normal, you come down on your heel and you can go off on your toe and that one there [original AFOJ you walk flat footed (FG#3,857-871)
B: The same? same as 'A' was saying that this one [ToeOff AFO] is you're on your heel and toeing o& that [original AFO] is just a flat foot ... you tend to walk more like a nonnal person (FG#3,894)
C: ..- I found that I can't bend my knet you know to do walk properIy7 my knee won't bend so.,. I walk Wre a lot of people fiom my hip,.----but with this [original AFO] I walk throw my leg around and it means Wre my foot is liLe tbat it bends up like that..-with that one [Toeoff M U ] because it wasn't so heavy I was still throwing out a little bit but not as rnucL.and it my foot was straighter (FGCL, 959)
D: Yeah, it is Actually it is straighter, and um oh there's something eke I wanted to say.-- and you don't havt to swing yom leg as much.-[a= as much, that's right]-.like if I'm uying to put speed on with that one [original AFO] I'm Swinging it, [a: oh ye4 I know I'm swinging it (FG#l, 968)
However, the following petson found the reverse:
oh I. know what my therapist tells me is that in order to walk properiy is that I have to put my heel down [heel first] and I don't get my heed down with this brace VoeOBF AFO] OIL I go fonvard, my foot goes flat (FW2'751)
Stairs
There was a consensus among participants that it is more di££icuIt to go down stairs with ToeOtr
than with their original AFO, although the lightness ofToeOff is an advantage when going up stairs:
A: Ideal for going up steps by the way because it's so tight [To&fFAFO] (FG#l, 842)
B: Going up the steps, but I'm a little leaq coming down the steps (FG#l, 854)
I find when I walk down stairs with the black brace on, it's very rigid, so there's no give to it at all, I feel like a stifT leg, is when I step down, I have no trouble coming up, but going down I, I can do so much better with this one [original AFO] (FG#4, 1095)
Well 1 noticed when I'm coming down the stairs it [ToeOff AFO] doesn't bend at the at the front, The old brace the leg was free to move or fiee to bend.- much easier to walk down stairs with the old brace than with the new one (FG#3,210)
r11 be a little slower and TU be a Iittle more care11 which way I put my foot down on the steps [with ToeOff AFOJ .-.because I always feel that if tie toe part is on the edge of the steps, that I'm going to go face down (FG#1, 902)
The individual who had an anterior fitting hinged orthosis to assist with plantarflexion,
however, found the reverse:
. ,, this one [original AFO] is so much stiffer and going down stairs I have to be sure to step on the edge of the tread, to go dawn, whereas with the black one it's got that flewbility, which I don't wan, but going down stairs it's more forgiving. Now what will happen with this if I, if1 don't get to the edge of the tread it pushes me up in the air, when I'm trying to step down (FG#4,lI05-1106)
and going up stairs, this one [original AFO] is be- because it supports my foot, I don't have to get my foot all the way onto the stair tread, whereas with the black one if1 don't get al l the way on I've got the same problem as I have without it, my foot folds up, and I can slide back off the step (FGW, LlL5)
Most participants lad noticed the spring Hkct of the ToeOff sole plate, although this was not the
focus of discussion. Two people found the spring &kt disconcerting:
I found that with the spring upset me- I found I was a bit out of balance,that very powerfid spring, and that's, I mean, it does solve the probIem of lifting your toes, it really does (FG#2,183-485)
A: Now one of the things that the black brace was supposed to do is give you a little spring when you're walking
B: It doesdo that
A: Does it?
C: L noticed it when I first put it on, but I don't notice it now
B: It gives you more spring certainly than that [original AFO], the only spring you get is fiom here
A: So do you like that, the little spring?
B: If I know where I am, I wouldn't do it in a place that I don't know (FGM, 1176- 1206)
The -dual with a plantarflexion assist originat orthasis found that the s p ~ g effect of T a
was insufficient for p-diag plantarflexion, in his case-
D: and what I find is that, L can notice that there's a bit of spring there, but it isn't enough (FGM, 12284235)
4.6.3 Comfort
Comfort emerged as an important issue in all four focus p u p s , and was identified as one of the
main factors contributing to satisfaclion with an AFO:
A: You said something interesting, you said if it's comfortable, anything that's comfortable is ok for you
B: That's right, if it's comfortable
A: So, yeah.--
C: I'd agree with, I'd agree with 'B' there too
D: Yeah, so would 1
A: Yeah so that seems to be.--
C: Comfort is a big thing (FG#l, 33 1-349)
Each individual had different comfort issues, for esample one individual was unable to wear Toeoff
because of spasticity in her toes, which resulted in her toes pressing against the portion of the T o m sole
plate wlWi curves upwards, and caused her great pain. Another individual found that ToeOffrode up
and down on his shin. Other people either found TceOffinitialLy comfortable, or had no problems once
individual adjustments were made,
Weight
In gene& the lightness of ToeOf!fgreatly conmr'buted to its comfort, and a few individuals found
it cooler to wear
Just it's the lightness you see, I mean this [original AFO] isn't heavy really compared with you know the old steel things they used to wear, but at the same time it can fcel like pounds by the end of the day, that's [Toeoff AFOl so light (FG#I, 857)
I get the feeling when I'm going forward with the affcctcd Icg first that it's so light that I feel Iike somebody's pulling it like a-.. like a puppet on a string, because it it seems to go up so much lighter-.- and it doesn't sound Iike you're dropping heavy weight at the end of it, As for the other one [original AFOJ thump thump I fctl as though all my neigilbours can hear me coming (FG#l, 953)
I found this one [original AFO] was just no give to it, and it's there, like you h o w that piece of plastic is there for He, no doubt about it, whereas this one Foeoff AFO] I just sort of: you don't d y feel it (FW3, 1460)
Not all participants noticed the difference in weight between ToeOffand their original AFO, however.
While nine participants found Toeoff lighter, two participants said they were unable to discern a
difference in weight.
4.6.4 Appearance
Colour
Witlun this population, the appearance of the brace, particuIarly colour, was more important to
the women, In tlle focus group wl~ich consisted of only two men, the colour of the brace was not raised as
an issue until the moderator addressed the topic of appearance, In the other three focus groups, however,
female participants idenhfied the bIack colour of ToeOff as a major disadvantage, almost fiom the outset
of discussion:
... 'cause in the summer you wear IigJrt clothes and it would be so, you know all you need is bright light and you could see it right tlmugh it, For vanity I tlunk for a woman (FG#l, 1776)
Especially for a &male, a man they wear pants most of the time but a woman wears a dress and it looks really nice [SafcaStic tone] when you're dressed up and a bIack thing hanging oa your leg (FG#3,87)
The d e did not object to the bIack colour of ToeOfE
Oh I woulddt give a damn what colour it was--- could be pink with purple polka dots for all I care @GM, 273-287)
From a guy point of view of course the black, Erom a guy point of view the black's fine because you know it's black or blue slacks generally (FGM, 381)
Although ody the women were emphatic that the colouf of ToeOfl:shodd be change during the
discussion male participants agreed that a flesh tone would be preferrable. Participants also thought that
the padding of the brae should match the colour of the brace itself, rather than providing a biack brace
with padding that is white or flesh coloured as is done currently-
Style
In terms of style, there was a definite trend for younger people to pfefer the look of the
ToeOff AFO:
A: M y kids think that the black one is better than, it's nicer than the
B: Oh I know? 1 know my kids do too but they're not the ones that have to wear it (FGM. 375-378)
A: Yeah, it's finmy because the kids feel that it looks less, uh it looks iike you have much of a ligilter problem [with ToeOff AFOl than that one [original AFO] looks like you're in trouble for life (FGM, 69 1)
The 17-year old participant also definitely preferred the look of Toeoff? and suggested that the style could
be enlunced by providing coloured designs that could be applied to the fiont-
4.6.5 Application
Putting On
Because the on 'g id AFO is worn posterior to the calf while Toeoff is worn anterior to the sh@
the two braces are applied diBefendy- When applying the original AFO, the foot goes in the brace More
putting on the shoe, With ToeOfft the brace goes in the shoe before the foot. There was a consensus
among participants in all focus groups that it is more dBicult to apply the ToeOg AFO, in comparison to
their origikl orthosis:
That part is good with the black one, that you, the shoe is, has the brace on, but uh I find it easier to put the, have this [original AFO] on, just like you put your sock and then you put this, and then you put the shoe (FGAfQ, 1500)
You tend to have to be a little bit of a contortionist [putting Toeoff AFO on], cause I lnve to stand up and bring my shin into the brace because of the gap that I have at the front and I'm trying to reach around and grab the strap, thaak god they put the extra little bit on the back of it for me there, made it easier to grab (FG#3,718)
TIER women also found that it was more diflicult to fit pants over ToeOE, because it is on the anterior
part of the leg. Participants did not have difficulty removing either orthosis.
One-Handed
When discussing application, a major theme was that many participants were only working with
one functional band, and in some cases this was their nondominant l w d , People with two hctional
hands did not find application of ToeOff much more difIicuIt. However, nine of the eleven participants
able to wear both orthoses had onIy one functional hand, and found application of the anterior fitting
ortl~osis considerably more difficult:
They're awkward to put on, I'd like somebody to really think about particularly, I'm sure tint I don't know if it's occurred to the designer that wiiie 3f these patients may only luve one working hand, and that's just tricky (FG#2,379)-
I find it very easy to put on, the white one, the black one f have trouble, weU because L only have one hand, that's, you know it's, I'm working like underneath my leg for this one, you put it, it was so easy, you just grab it, put it through there and it stays right there, where the black one, I'd always keep my brace in my shot, and I put my foot right in my shoe. I can't do it the other way (FGM, 1497).
This uh one here [original AFO] the strap is in h n t , very easy to put on- This one FoeOff AFO], the strap's in the back, I'm righthanded and L do everything left now- It's that much tougher anyway (FG#3,709)-
Shoes
Another major theme in the area of application was shoes- Despite its thinness, most prticipants
did not find that the ToeOEAFO could fit in a greater number ofshocs, although some had not tried, One
person had tried both braces in each pair of his shoe collection, and was able to wear ToeOff in a few
more pairs. Two people had difficulty wearing ToeOffwith sneakers, although four others regularly wore
it with shoes, Two people were able to wear the ToeOfll AFO with boots, but had not been able to
do so with their original AFO:
Now one advantage I do find with this [Toeoff AFO] is the fsct that you can put it into the shoe, and then put the shoe o n This one [originaI AFO], because of the way 1 have to fit it, which is - I have to go on that way, and then twist on, 1 can't, you know I have to put it on first, and that makes it very difficult putting boots on, you know, hiking boots, something Like that (FGW, 447)-
Thee individuals enjoyed wearing their original AFO with sandals in the summer, and the inability to use
ToeOff with sandals was noted as a disadvantage-
Persons who had required a shoe one size larger on the afEected side, to accommodate the
original Am, were abie to wear two shoes of the same size with ToeOK The cost associated with buying
special shoes to accommoda!e AFOs was noted as a definite disadvantage, particularly when two pairs of
shoes were required:
I tlunk that a tittle more thought might be given to getting it on, and particularly a brace that would generally speaking fit all shoes, cause most of us have to buy shoes to get that boot [original AFO] into it, and probably buy two pairs, one bigger one to fit the brace, and one to put your other foot in, and that's expensive (FG#2,415)
Do you fwd that you have to get shoes, *ce like bigger than what you normally ... to accommodate for it? This one's [original AFO] worse than this one, than the new one, because you got more here [in the width], that you've got to accommodate for (FGW, 423)
4.6.6 User Recommendations
User recommendations for the ideal AFO, as we11 as recommendations for imptovements to their
original and ToeOff orthoses, are mmmarkd in Table 1.20,
Table 4.20 User Recommendations for Ideal, Original and ToeOff AFO
4,7 Clinical Assessment
To facilitate analysis, individuaI results from the ciinicai assessment have been organized into 4
groups: persons demonstrating positive PC1 results or energy savings with Toeoff, persons demonstrating
negative PC1 results or additional energy cost with T e , persons showing no change, in terms of PC1
results. with Toeoff, and persons unable to wear tile ToeOff orthosis (see section 4.3-1 for explanation of
PC1 results). Individuals who withdrew fiom the study were not assessed- For range of motion, muscle
strength and spasticity measures, group means and standard deviations are presented; for ankIe stability
and somatosemrq. function, the percentage of individuals within each group who were rated as impaired
is reported However, given the small number of participants in each group, results must also be
esamined individually.
TueOf€AFO Change colour to flesh tone Match colour of padding to brace Facilitate application, especially for individuals with only one functional
Ideal AFO I Origiaaf AFO
1 lndividuaLLv adjustable Minimal cost
Easyto apply Wute or flesh colour Fit in almost all shoes
hand Lengthen straps Allow for more individualization (spring rate, sole plate width)
Remm as much materid as possrMe to make smalI-, cooler, lighter
Lightweight Cover up hinge so it doesn't catch on clothing
4.7.1 Range of Motion
The active and passive range of motion of the affected ankIe, kaee9 and hip of all particips are
reported in Tables 4.21 and 4.22 e- Participants who achieved energy savings (see section 4.3-1
for explanation of PC1 d t s ) with ToeOEdemonstrated a greater range of active arid passive ankle
dodesioa compared to participants in the other three groups, When dorsiflexion was measured fiom a
supine position with the hip extended, only two participants (S12, S16) demonstrated active dorsiflexion
past neutral, and only three (S12, S 15, S16) demonstrated passive dorsiflexion beyond the neutral
position. Ail of these participants demonstrated energy savings with T m no participants in the other
tluee groups demonstrated active or passive dordexion beyond the neutral position, when measured in
tlus position, When dorsiflesion was measured h m a supine position with the hip and knee in flexion, 4
of the 7 participants who showed positive PC1 results with ToeOff exhibited some degree of active
dorsiflesion past neutral, and 6 exhibited passive dorsiflexion beyond the neutral position, Among
participants who did not show positive PC1 results with ToeOff, none showed actbe dorsifleuon past the
neutral position and only two (S10, S14) demonstrated a small amount of passive dorsifle.Gon beyond the
neutral position, when measured h m this second position,
Participants who demonstrated positive PC1 results with ToeOffaIso had greater range of hip
e.xtension, compared to participants in the other three groups. AU participants who achieved positive
results with ToeOff demonstrated active and passive Iup extension, when measured in side lying. Ofthe 7
participants who did not demonstrate positive PC1 results with Toe= 4 were unable to actively extend
their hip past neutral, and 3 were also unable to do this passively, With one exception (S lo), individuals
who did not demonstrate positive PC1 results but were able to exrend their hip past neutral e.xhiiited less
l ip estension than the m a n active and passive hip extension range for the group that did achieve positive
PC1 results. For all other range of motion measures, there was no clear distinction between individuals in
the four groups, and considerable overlap was seen.
Table 4.21 Active Range of Motion (degrees) of the Affected Ankle, Knee and Hip .
Subjec$ Ankle Ankle Ankle Kaee Knee Hip Hip Number PF DF DF F E F E
(supine) (supine (3tqYhe (Eidtlying, (dttfngj- ( s n p - i ) ((ode hipand hipand hip E) MW)
Results Nochange
LEGEND: PF - plantarflesion; DF - dorsifleuoo; F - flexion; E - extension
S8 58 -10 4 5 0 -50 108 0 S2 50 -40 4 1 90 -20 1 14 -14
W e a ~
- AnWe dorsiflexion of O0 corresponds to no movement past the neutral position, that is, the ankle is actually at 90°, Negative values represent @tiom which are a d y within the plantarflexion range,
.I
that is, the participant was unable to dorsineu beyond this point, Knee esteension of O0 corresponds to normal range or full extension; negative d u e s represent angles below full estension
S 14 62 -8 -24 75 0 45 8 S3 26 44 -26 87 40 90 -14
Group Mems
(Std*Dev*)
PO&'^^^^ 57 (I 3) -7 (26) -27 (29) 86 (35) -13 (18) 106 (21) 12 (5) N ~ t i v e 60 (3) -34 (34) -52 (9) 45 (64) -32 (26) 107 (1) -5 (7) No C ~ W F 58 (1 1) -22 (25) -30 (16) 90 (0) -10 (14) 102 (17) -1 (18)
Couldn't Ws 48 (19) -17 (11) -30 (9) 75 (12) -22 (20) 75 (26) 0 (12)
Table 4.22 Passive Range of Motion (degrees) of the Affected Ankle, Knea and Hip
(+) PC1 Results
(-1 P a Results
N0Ch-g~
LEGEND: PF - plantarflaxion; DF - dorsiaesion; F - flesion; E - extension
SS 69 5 0 136 0 120 19 S9 71 7 -32 121 -10 133 15 S l 1 68 -LO -5 113 -35 107 10 S 12 47 LO 10 30 0 127 25 S 15 72 9 4 130 -10 112 18 S 16 44 14 17 138 0 124 13 S1 67 0 -18 110 -10 110 -3 S8 70 0 -45 120 0 118 9 S2 51 -18 -14 120 -19 118 0
Group Means
(Std-D~b~.)
Ankle dorsiflesion of O0 corresponds to no movement past the neutral position, that is, the ankle is actually at 90°. Negative values represent positions which are actually within the pIantarflexion range,
.. that is. the participant was unable to dorsifles beyond this point. Knee e~qension of O0 corresponds to normal range or M extension; negative values represent angles below fir11 estension.
posi t ive~I 63 (12) 6 (8) -2 (16) 111 (37) -8 (13) 120 (9) 16 (5) Nwtive 69 (2) O ( 0 ) -32(19) 115(7) -5(7) 114(6) 3(8) No Change 60 (8) -8 (14) -12 (3) 117 (5) -10 (13) 108 (14) 8 (11)
CouIdn'L 57 (13) L (2) 4 (3) 114 (2) -15 (17) 67 (61) 6 (10)
4.7.2 Muscle Strength
Muscle strength of the aEected ankle, knee and l ip is reported in TabIe 4.23- It was expected
that individuals with limited ankle plantarflesor strength would benefit most fiom the ToeOff orthosis,
One individual who showed negative PC1 results with ToeOff(S8), and one individual who showed no
change in PC1 with ToeOff (SIO), demonstrated ankIe plantarflexor strength which was higher than that
of 6 of the 7 participants who showed positive PC1 results. However, another individual (SI2) had good
plantarflesion but still exhibited energy savings with T-
Participants who showed negative PC1 rcsults or were unable to wcar ToeOBFshowed low muscle
strength of the knee extensors and hip flexors, compared to who showed positive PC3 results
or no change.
Table 4.23 Muscle Strength (kg force) of the ARected Ankle, Knee and Hip
LEGEND: PF - plantarfiexion; DF - dorsiflesion; F - flesion; E - exqension
(+) PC1 Results
(-) PC1 Results
No Change
UnableTo Wear
Group Means
(Std.Dev.)
*participant was too strong for the examiner and strength could not be assessed; the value of 27.0 kg was estimated as the participant's minimum strength of this muscle group for the purpose of caIculating p u p means
Subject Ankle Ankle Knee Kna Hip Hip Number PX? DF F E F E
(suqic+Ioag (supindong (siningkneeat (siningbrctat (sqhc) (suphe bip& 1 riainn) 90) 90) b 9 0 )
S4 4 3 0.0 7.2 22-8 1 0 2 153 ss 5-5 1-1 5-3 ntoz 9-6 11-0 S9 1.7 0 18 I6 12 13 S l l 0.5 0-4 0-8 1-7 2-0 2-4 S 12 19-6 3 -7 13.0 21.4 23 -0 27,0* S 15 4-0 5.8 7.4 20.5 14-0 27,04 S 16 3-7 10.0 18.6 9-4 27-04 11-5 S1 2-9 0-0 9-8 3.9 8.6 12-1 S8 7.8 0.0 2.0 8-4 7.7 10.4 S2 1.6 0.0 2.3 19.6 21.6 15-0 S 10 6.8 5-7 5.0 26.2 11.4 19-7 S3 1-4 0-0 0-6 4.6 7.1 8-9 S6 5-9 1.3 2A 7-1 5.3 12-35
S 14 5.6 1-3 2-4 4.5 4.0 7.6 , I
P ~ i ~ i v ~ 5.6 (6.4) 3 (3.8) 10.0 (6-7) 17-0 (8-7) 14.0 (8.5) 15-3 (8.9) Neg;rtive 5.4 (3-5) 0-0 (0.0) 5.9 (5.5) 6-2 (3-2) 8.2 (0.6) 11-2 (12) N o C k g t 4.2(3,7) 2-9(1.0) 3,6(1,9) 22-9(4-7) 16.5(7.2) 17.4(3.3)
C o u I d t t W a 1.3(2.5) 0-g(0.8) 1.8(1.0 5-4(1,5) SS(1.6) 9.7(2.5)
4.7.3 Spasticity
Modified Ashworth ScaIe ratings of ankle pIantadle.sor spastl-city are presented in Table 4.21-
Moderate or severe spasticity are reported as contraiadications for TocOffon the product bmchure
(International Orthopedic Markctin& 1998)- There was no reaI Werence, in terms of Modified
Ashworth Scale ratings, between participants in each of the four groups- Most participants had no ankle
plantarflexor spasticity, The highest rating within this population was '2', but was reported both for one
individual who demonstrated positive PC1 d t s with ToeOff (SS), and for one individual who was
unable to wear the ToeOfforthosis (S3).
Table 4.24 Modified Ashworth Scale Ratings of Plantamexor Spasticity
I Subject# Rating I
(+) PC1 Results
Results Nochange
Results fiom the Pendulum Test are reported in Table 4.25, Individuals who were unable to wear
the ToeOff AFO demonstrated fewer oscillations in LO seconds than the average number of oscillations for
S8 1 S2 0
Unable To Wear
Group Means
(StdDev.)
those who achieved positive PC1 results with ToeOff The relasation index is calculated as the ratio of the
initial knee flexion angle to the final knee flesion angle, and showed no clew diffierence between groups.
S6 0 SlS 0 S3 2
Positive PC1 0-4 (0.8) N-tive PC1 0.5 (0-7) No Change 0.5 (0-7)
Couldn't Wear 0.7 (1 -2)
- 4.7.4 Other Clinical Measures
Ratings of ankle stability in two-foot stance and ratings of somatosensocy f - o n are reported in
Table 4.26, There was no real difierence in any of these four measures, between the four gmups.
IndividuaIs who were rated as impaired in one, two, or three of the tests, in some cases, were still abie to
achieve positive PC1 results with ToeO&
Table 4.25 Pendulum Test Results
(+) PC1 Results
(0) PC1 Results
Qo Change
Subject OscilJatioas in Initial Knee Number 10 seconds Flexion Angle
S1 4 60
FindKnee Relaxation W i o n Angle Index
65 0.92 76 0.83 72 1-07 70 0-93 70 1.37 68 O,% 72 1.32
Group Means
(StADev.)
Positive PC1 5-1 (1.6) 74-4 (25.3) 70.4 (3.5) 1- 1 (0.21) Negative PC1 6-0 (0.0) 86.0 (1.4) 74-0 (5.7) 1.2 (0-07) No Change 12.0 (8-5) 68.5 (26.2) 70.5 (10.6) 1.0 (0.23)
Couldn't Wear 3 -7 (1.5) 63.0 (16.5) 63.3 (12-1) 1.0 (0.10)
Table 4.26 Ankle Stability and Somatosensory Testing
Re!dts
(-1 P a
L S14 I>m red &lGr I- intact .L)u -
14 28 57 14 0 0 0 50 50 50
33 0 3 3 3 3
Subject Ankle Light Pin Pro- Number Stability Touch Prick Prioception
(2-foot stance) (foot) (foot) (big toe) S4 Intact intact impaired intact SS Lntact intact intact intact S9 Catact intact intact intact
S11 hpaircd intact impaired Impaired S12 Intact impaired impaired intact S15 Intact intact intact intact S16 Intact impaired impaired intact S 1 Intact intact intact intact
Results No Change
Unable To Wear
S8 Tntact intact intact intact S2 lntact intact intact intact SlO Intact Impaired Impaired 53 Intact intact intact intact S6 htact intact intact intact
CHAPTER 5. Discussion
5.1 Power Generation at the Ankle
It was e - s i e d that users would show an increased ankle power bwst at push-off on the affected
side, when wearing the Toe= AFO compared to their originally p r e s c n i orthosisosis However, this effect
was demonstrated for neither of the two participants for whom gait d y s k was performed The first gait
analysis was performed on a partkipant who demonstrated an increase in energy expenditure, in terms of
PC1 results, when ivearing ToeOff- This individual showed a decrease in ankle power on the affected side,
when wearing ToeOK Tile second gait anaIysis was performed on an individual who showed energy
savings, in terms of PC1 results, when wearing ToeOK For this participant, ankIe power on the &ected
side was slightly lower with the ToeOfforthosis, However, this individual's original orthosis was a
plantarflesion assist anterior Ilinged orthosis, which is designed to substitute for weak plantarflexors and
therefore may provide more assistance at p u s h 4 than would a dropfoot orthosis, This participant found
that the ToeOEorthosis did not provide enough resistance against dorsiaexion at push-off, and reported
that waking with ToeOff w a s more difficult, although llis PC1 results demonstrated energy savings with
ToeOff. These energy savings may be the result of the increased work seen at the unaffected knee (K2)
and Iup (H3) when wearing ToeOff (Table 4.4). This single gait analysis, in combination with the
participant's subjective report, found that ToeOffms slightly less effective as a plantarfledon substitute
than his original plantarflesion assist AFO- It is likely that T o e was inadequate to support this
participant's weight, and therefore did not provide sufficient resistance against dorsiflexion or spring
effect at pusl1-oE
Uneqectedly, for both individuals an increase in ankle power was demonstrated on the
unaffiited side when wearing Toeoff* A possible esplanation is that participants were able to achieve a
more natural foot contact of the affected tide with Toeoff, which provided greater stability of the affected
limb at this period of the gait cycle, and enabled both individuak to t&e better advantage of the push-off
capabilities of the unaffected side-
The hypothesis of an additional power burst on the af]Tected side when wearing the ToKlEAFO
w a s not supported by- the case studies (Appendix I & J;) reported he= However, the first case
demonstrated increased energy costs with Toeoff, in terms of PC1 results, which suggests that she may
have been unable to take advantage of the dynamic properties of ToeOE The second case had an original
plantarfledon assist AFO, which likely provides more power at push~f f than a dropfwt orthosis, Thus
the results of these two case studies are inconclusive- Further gait analysis of individuals who
demonstrated energy savings with T e in terms ofPC1 results, is necessary to determine ifthese
savings are the result of an additional power bum at the flkcted ankle during push-offl
5.2 Energy Cost of Walking
It was hypothesized that users would demonstrate evidence of reduced energy costs during
ambulation, when wearing ToeOffcompared to their originally prescribed AFO. There was no statistical
difference in mean PCI, w~.alking speed or distance wvallced between the two orthoses, although a trend
towards lower PC1 at fast waking speed was shown @=O.Of). Overall, the research hypothesis of lower
energy costs of walking was not supported by group results.
Although the group results are indicative of no difference between orthoses, individual resuits are
clinically importanb and the small sample size makes it difficult for statistical signiiicance to be achieved,
Combining the PC1 and sis-minute waking test results, seven participants showed gains or probable gains
when wearing the ToeOff orthosis. Four of these participants were able to increase the distance walked in
sis minutes, when wearing ToeOK Two individuals showed no real dserence behveen orthoses on the
walking tests, and two individuals demonstrated negative results- In summary, ofthe 11 participants who
trided tl~e ToeOff AFO, 64% showed a decrease in physiological cost with Toeoff, 18% showed no
change. and another 18% showed negative results. Overall the lkypotllesis that participants would
demonstrate lower pI~ysioIogid cost of wvahg with ToeOff was supported by individual results,
although not for each person.
Activity levels during a typical day can help to substantiate results of the walking tests, or to
analyze a user's performance with ToeOff when the results of walking tests are inconclusive. For
example, the PC1 resuIts of one participant (SIS) at seIf4ected comfortable walking speeds and two
participants (SJ, SL 1) at seIf4elected fhst walking speeds were interpreted as probably positive (see
sections 3.3-1- 1 and 43-12), These participants showed an increase in walking speed when wearing the
ToeOff AFO, but aIso showed an increase in PCI, Looking at individual changes in physical activity
levels as measured by the ActRe during a typical day (Figure 4. IS), all three of these participants showed
an increase in the percentage of waking time spent in physical activity, when wearing the ToeOffA.0
compared to their originally prescri'bed orthosis- These individual Act& results are consistent with the
interpretation of their PC1 results as probably posithe.
5.2.1 Comparison with Normal PC1 and Six-Minute Walk Results
A study of 34 nonnal adults aged 53 to 85 reported PC1 values at sewselected comfortable and
fast waking speeds (Chen, 1997)- For the 15 men, mean PC1 was 0.326 (+/- 0.083) and 0.1 I6 (+/- 0.097)
at self-selected comfortable and fast walking speeds respectively. For the 19 women, mean PC1 was 0.479
(+/- 0.109) and 0-538 (+I- 0-101) at df4elected comfortable and fast walking speeds respectively. In
general. PC1 values for participants in the current study were notably higher than the mean PC1 values for
healthy adults at both walking speeds-
The range ofPC1 d u e s obtained by Chen (1997) was 0.213 to 0,503 for men and 0.307 to 0.730
for women at self-selected comfortable speeds, and 0267 to 0.626 for men and 0.3 12 to 0,764 for women
at self-selected fast walking speeds. Several participants in the current study, although above the mean
normal PC1 value- fell within the range of normal PCL values reported in Chen- This was the case for four
individuals (Sl, S5, S8, S16) at comfortable walking speeds, and six individuals (Sl, S5, S8, S9. S15,
S 16) at fast walking speeds. Another two individuals (S4, S9) were within the n o d range of PC1
vdues at comfortable walking speed when wearing the ToeOff orthosis only. Note that the individual who
used a walker (S 11) was well below the normal range of PC1 values at both walking speeds and with both
AFOs.
Mean comfonable wvaiking speeds reported by Chen (1997) were 80.5 1 (+/- 1.34) m/min for men,
and 70.40 (+/- 1- 17) dmin for womea The range of comfonabIe walking speeds was 5 1.51-100.18
Wmin for men and 55-02-99.52 mlminfor women Except for one male (S16) who excetded the mean
n o d walking speed reported by Chen with I& original AFO only, all other individuals were weil below
normal walking speeds, and most participants were also we1 below the lower limit of the normal
comfortable walldng speed range, This implies chat in order to maintain an acaptabIe level of energy
espenditure. participants in the current study substantially decreased theu walking speeds- The fact that
their walking speeds were well below the lowver limit of the normal comfortable walking speed range
indicates that participants may have dficulty wMth community ambulation, for exampie crossing a busy
intersection before the Iight changes*
Mean fast walking speeds reported by Chen (1997) were 104.13 (+I- 1-74) d m i n for men, and
85-62 (+/- 1.13) d m i n for women The range of fast walking speeds was 89.69-127.24 m/min for men,
and 61.70-109.67 mlmin for women, A single individual (S16) approached the mean fsst walking speed
of normal older adults with both orthoses. AU other participants were well below the mean fast walking
speed of normal older adults, and most were also well below the lowver limit of the normal fast walking
speed range. Again this indicates that in order to maintain acceptable PC1 levels, participants attained a
notably lowver muimum waking @
Enright and SherrilI (1998) reported reference equations for the &.-minute walk in healthy
adults aged 40 to 80 years, wluch explain about 10% of the variance in the distance walked by healthy
adults. For men the predicted sis-minute walk distance (6MWD) is calculated as 6MWD, = (7.57 s
h e i g h a - (5.02 s age,-) - (1-76 s wveightd - 309,, wvllile for women the equation is 6MWD, = (2.1 I x
heighw - (5.78 s age,,-) - (2.29 s wveightd + 667,, Using the mean height, age. and weight of maIe
participants in the current study, the p d k t e d six-minute walk distance is 601m; similarly, using mean
values for female participants, the predicted sixminute walk distance is 535m- The data for subject 12,
who was 17 years of age, was omitted fiom these calculations. Em-ght and Sherrili (1998) also indicate
that the lower limit of the normal range can be obtained by subtracting 153111 and 139m from the
predicted values for men and women respectively: for the current data the lowver Iimit is 418m for men
and 396m for women,
In general, the sk-minute walk distances ofparticipants in the current study were well below the
predicted distances for healthy adults of the same gender and mean age, height, and weight. Only one
male individual (S 16) waiked fbrther than the predicted distance, travelling 62 lm and 624m with his
original and T e o r t h o s i s respectively- Another maIe participant (S2) was just above the lower Iimit of
the normal range with his on- AFO, and just below this Iimit with ToeOfX None ofthe female
participants attained the predicted six-minute walk distance, and all were below the lower h i t of the
normal range. With one exception (S2), participants who had s u t r i a stroke walked distances well
below the lower limit of the normal range for healthy adults- Tile two participants who had not dd a
stroke (S 12, S l6), however, were able to walk normai distances- Since the six-minute walking test is a
measure of physical function ( E ~ g h t & Sherrill, 1998), and participants who had Mered a stroke
esht'bited below n o d results on the sis-minute walking test, these participants wodd be e-vgected to
have above average difficulty performing daiiy activities. The two participants who had not Mered a
stroke, however. would be expected to have less difliculty undertaking daily activities.
5.3 Participation in Daily Activities
Because the ToeOfForthosis was designed to conserve energy for the user, it was expected that
participants would be more active and/or less fatigued in a typical day, when wearing ToeOff as opposed
to a conventional AFO, ActRe results sho\ved that when wearing ToeOff, participants decreased the mean
percentage of waking time spent resting as a main activity @=.032), and increased participation in
recreation and leisure activities (p=.024), while maintaining the same levels of fatigue- Overall, the
hypothesis tlmt participants would be more active in a typical day when wearing the ToeOff AFO was
supported.
There was no difference in the mean percentage of time spent in physical activity, when wearing
each of tire nvo orthoses- Individual changes in plrysical activity Ievels, howvever, generally conesponded
to the changes in energy cost determined using PCI, That is. individuals who demonstrated a lower PC1
and/or faster wvalking speed. when wearing ToeOK also increased their physical activity in a typical day
when wearing this orthosis, and vice versa This d t is noteworthy, because it suggests that PC1 results,
which are calculated during timed walks in a controlled environment, may be M e n a b l e to everyday
environments.
Results of the walking tests, although performed in a controlled environment, have implications
for participation in daily activities- Walking speed and endurance have important implicatians for
community ambulation, for example the time required to cross an intersection or to navigate a shopping
mall, Walking speed has also been related to independent living and recurrent fidk among the elderiy, a
faster walking speed correlating with independent living and fewer fdIs (Cunninebsm. Paterson Himann,
& Recimitzer, 1993; Lipsitz, Jonsson, Kelley, & Koestner, 1991)- At self-selected comfortabIe walking
speeds, four individuals (S4, S12, S 15, S16) increased their walking speed by more tban 10% when
wearing ToeOfff compared to their original AFO, while one individual (S2) dec read his walking speed
by more tlm 10% At seLf-selected fhst walking speeds, three individuals (S4, S11, S 15) increased their
walking speed by more than 10% when wearing ToeOff, while one individual (SS) decreased his waking
speed by more tlw 10%. Three individuals (S4, S 12, S16) who increased their self-selected comfortable
walking speed and one individual who increased lu's seE-selected fast walking speed (S 15) also showed a
decrease in PC1 with ToeOff. However, one individual (S 15) increased his comfortable walking speed
with a comparable increase in PCI, while two individuals (W, S11) increased their fast walking speeds
with a comparable increase in PCI, Although tluee individuals sacrificed increased energy costs in order
to aclueve the faster walking speeds, this increase in speed may still be beneficial-
The speed at ~vlucl~ participants cfloose to walk, when wearing each AFO, is funcaonaIly
important. An Af;O wluch permits a faster walking speed may permit greater participation in daily
activities, and vice versa. Although most participants showed no real difference in walking speed between
the two orthoses, the increases and decreases in speed made by the above individuals should be noted,
along with their possible hnctional implications-
In general, focus group discsion did not substantiate the ActRe findings. Participants did not
report feeling more energetic or being able to do more when wearing ToeOK It is possiile that the
difference in activity levels, although sigficantf was not large enough to be noticeable. For someone
who is antake 60% of the day? a 6% decrease in the amount of waking time spent resting corresponds to a
reduction of rest time by 52 minutes, Spread throughout the day, the additional 52 minutes now avaiIabk
for other activities may not be perceivabk, partkukly since fatigue levels were reported to be the same
with both orthoses-
5.3.1 Comparison with Normal Time Use Values
The &ct that participants increased time spent in recreation and leisure corresponds with
research that bas shown drat older persons spend more time in activities which they prefer and choose to
do, as opposed to activities d a t e d with obligation (Lawton, Moss, & FuIcomer, 19864987)-
Furtilermore, the strongest determinant of time dlocation, beyond demographic characteristics, has been
identified as functional health (Lawton er aL. 1986-1987)- Persons with Lower hctional health have
lower Ievels of independence, and spend less time in obligatory activities (Lawton et aL, 1986-1987; Ross,
1990).
The mean age of participants in the current study was 54 [+/- 15). Among persons aged 45-64,
labour force status is the primary determinant of time allocation, with employed individuals having less
time for unpaid work leisure and personal care (Statistics Canada, 1995)- Only one participant in the
current study was empIoyed part-time. and one attended higlwIool111-time- According to the 1992
General Social Survey on Time Use, unemployed adults aged 45-64 spend an average 8-1 hours in leisure
activities and 8.0 hours in sleep (Statistics Canada, 1995). Tilts leisure time corresponded to 51% of
waking time for these respondents to Statistics Canada, indicating that at 33.5% of waking time with the
original AFO and 39.5% with ToeOff; participants in the current study were still well below the national
avenge. This suggests that if the energy levels of these participants were increased, leisure activities
would be the natural category of time use within wluch increased participation would occur-
Respondents to the 1992 General Social Survey aged 45-64 spent an average 10.9 hours in self-
care, defined in the Statistics Canada study as activities fulfilling biological needs, and subdivided into
categories of sleep, meals and other (Statistics Canada, 1995). Combining Act& categories of sleep, rest,
selfare, and treatment, participants in the current study spent a mean 14 hours firlfilling biological
needs. wluclr is well above the national average. Due to disability, participants in the cunent study
allocated more time to rest and treatment, compared to the national population, With the T e
participants were able to conserve energy, spent Iess time resting, and devoted this saved energy to
recreation and leisure activities-
5.4 User Ratings
Subjective reactions directly affect users' willingness to wear assistive devices (Krebs et a[-.
1988). Comparative and noncomparative rating scales (Appendix F) were used to quickIy gather user
opinions about the two orthoses- Completed prior to the simninute walks with each Am, the
noncomparative rating scale asked users to rank each orthosis separately, using a 5-point Likert scale to
evaluate each of nine categories This scale provided an idea ofthe degree of participants' satisfaction
with each of the two orthoses- Completed after participants had lmd both AFOs for at least two months,
the comparative rating scale allowed the user to indicate preference for one of the two orthoses. or no
preference, in the same nine categories.
The hypothesis that users would prefer the ToeOffA.0 was supported by their ratings, although
statistid significance was achieved for only one dimension. On the noncomparative rating form, the
difference in ratings was statistically significant for comfort, with the I1 participants rating comfort of the
ToeOffortl~osis significantly higher than that of their original brace (p=.036). For the chosen dpha level
(p=.05), the median rating of the ToeOff AFO was not statistically diffierent Erom that of the original AFO
on any of the other dimensions e.Yamined- On the comparative rating form, statistical significance was
not achieved for any of the dimensions esamined. Significance was approached for three dimensions,
Iiowever, with a trend towards preference for T o m in terms of comfort @=,0625), walking on even
ground (p=.0625), and appearance @=.09)-
The fact that participants' ratings of the two orthoses were statistically different for only one
dimension is not surprising, given the smali sample size. In order for statistical significance to be
achieved with only 11 respondents, virtually all participants would need to have similar subjective
responses to the two orthoses. However, looking at the trends towards preference for one of the two
orthoses on each of the nine dimensions provides vahmbk information which can be huther explored with
individual participants or within focus group discussions.
Despite the fact that statistid sipiticance was not achieved, comparing the mean
noncomparative ratings and tallying the number of users indicating a comparative preference for each
orthosis on each dimension gives an idea of the direction of user preferences, Participants' mean
noncomparative Likert scale ratings were Iugher for the ToeOff AFO in terms of comfort, walking on
even grow& going down stairs, overall fimction, appearance and overall rating- For walking on uneven
ground and application the mean noncomparative Likert scale rating was higher for the original orthosis-
On the comparative rating scaie more participants indicated a preference for the ToeOfforthosis in terms
of comfort, walking on even ground, going up stairs, appearance and overalI rating. For waking on
uneven ground and going down stairs, more participants indicated a pteference for their original AFO-
When asked whether they had a preference for one of the two orthoses, or no preference, in tenns
of appearance, participants' responses demonstrated a trend towards preference for the T d f f AFO
(y.09). This result is suprising, considering the empIusis placed on dislike for the black colour of
ToeOff during focus group discussions (see section 4.6.4)- However, looking at individual ratings, five of
the seven participants who indicated a preference for the appearance of ToeOffwere male; aIthough males
agreed that a flesh tone would be preferrable, the black colour of ToeOff was much less of an issue for
men- Furthermore, the two f e d e s who indicated a preference for the appearance of ToeOff on the
comparative rating scale did not Iike the black colour. but overall still preferred the appearance of ToeOff
to that of their original AFO, Another female participant, who had previously indicated a dislike for the
black colour. indicated no preference for the appearance of either AFO on the comparative rating scale,
wlule hvo females indicated a preference for the appearance of their original AFO- Finally, one female
participant was unable to wear Toemand therefore did not complete the rating scales, but had strongly
opposed the black colour in the focus group discussion.
In general, the results of the noncomparative and comparative rating scaies were consistent.
That is, when participants assigned a higher noncomparative rating to one orthosis on a specific
dimensioa they also indicated a preference for that orthosis on the same dimension on the comparative
rating scale. The only exception to this was going down stairs - participants had a slightly higher mean
noncomparative rating of the ToeOff orthosis for going down stairs. but more participants indicated
preference for going down stairs with their original orthosis on the comparative rating scalee Since onIy
the comparative scale specifically quenquened participants about their preference between orthcses, the averall
trend is pteference for the original AFO for going down stairs- Furthermore, the focus group discussi011~
substantiated the overall trend of comparatiVe and noncomparathe ratings of each dimension, with the
esception of appearance. which has already been discussed above, Detaired rationale were given for
participants' opinions throughout the di-ons, which greatly enhanced the vaIue oftheir comparative
and noncomparative ratings, For exampIe, the espIanations given for why users found it more diff~cult to
go down stairs with ToeOff were insightfbl and are clinically very usefi& particularly since the designers
probably could not have predicted that users wouId find it more diflkult to go down stah with TocOK
ActRe results also suggest that participants may ptefer the ToeOfforthosis to their original AFO.
The significant increase in wearing time of the ToeOBF AFO compared to that of the original brace, may
indicate greater user satisfaction with tius orthosis- However, this result must be interpreted with some
caution, since all participants were actively involved in the study, and reported deliberate attempts to test
the new brace under different conditions- Follow-up with the current participants is indicated to
determine whether the increase in wearing time is permanent, as well as which AFO users have continued
to wear.
5.5 User Thoughts and Ideas
Focus group discussions provided valuable insights into panicipants' experiences with their original
and ToeOff orthosis. The focus groups were semi-structured, and esplored participants' experiences
within four topic areas of hction, corncart, appearance and application, Coding of focus group data was
performed by thematic analysis, which irrvolved examining the data for common themes which were
constructed fiom the data. These themes were then organized under the four topic areas used in the
interview w-de.
Appearance
Stewart & Shamdasani (1990) suggest that the issues which f- group members raise first may
be the most salient or important to then In three focus groups, the black colow of the T-AFO was
identified by women as a disadvantage almost immediately, In the fourth focus group, which consisted of
two male participants, colour was not raised as an issue until the latter half of the -on, when the
moderator addressed the topic of appearance- Overall, the greatest number of text units were coded under
the theme of colour. Although all participants agreed that a flesh coIour would be more appropriate for
ToeOK female participants were especialIy unhappy with tbe bladr cdour, Women found the black
colour unfeminine, unattractivep and inappropriate to wear with a d m or shorts. The importance of
cosmetic appeal, particdarly for women, h a s previously been noted in the literature (Ofir & Sell, 1980;
Sarno & LeImeis, 1971)- Interestingly, although participants agreed that a flesh colour would be
preferrabie for ToeOff; they were not unsatisfied with the white colour of their original orthoses,
Directly related to dislike of the black d o u r is visiiility- Women were unhappy with the black
colour not only because they considered it unfeminine and inappropriate with a dress or shorts, but
because it is very visibIe and advertises their disability- In terms of style. male participants and younger
persons tended to prefer the more modern look of ToeOff, while others preferred the look of their original
AFO- Two women also commented that their children preferred the appearance of the ToeOff brace,
although they themselves did not, Although dislike of the black colour was not strong enough for female
participants to reject the ToeOff AFO, it greatly reduced their satisfaction with ToeOff.
Comfort
Coinfort emerged as an important issue in all four focus groups. and was idenwed as one of the
main factors contributing to satisfaction with an AFO. In general, an ortllosis that is not comfortable will
not be worn, In a subjective evaluation of ACL braces which included ratings of firnction, appearance and
application, as well as comfort, the importance of comfort was empilasized by doubling the comfort rating
before determining the final score (Alesander, 1995).
Several persons required individual adjustments to makc ToeOf€comfortable- It should k noted
that aIl edges of T o e a r e quite sharp, and thcretore potentially vtry damaging to the skin, After tht
first few fittings, the orthotist made it a practice to leave a r i m of padding around the exqetior border of
the orthosis, to prevent contact ofthe brace edges with tlre skin, One individds foot was slightly longer
tlian the footplate of tlle Iargest size of T e , in this case the orthotist added a leather sole piece which
el-ended past the slurp edges ofthe sole plate, Three persons experienced discomfort due to pressure
from the anterior portion of ToeOff against their uiia This was aIIeviated by making a p v e in tile
padding at the pressure points, such that the pressure was disvliuted on either side of the prominent shin
bone, In one case the design of ToeOff could not accommodate an individual's comfort needs, This
person was unable to wear ToeOff because she had considerable spasticity in her toes and experienced
great pain from the pressure of the stiff sole plate, wluch curves up slightly at the metatarsals, against her
toes.
Participants' original orthoses were custom-fiibricated from a positive mold of the leg, while the
ToeOff orthosis is prefabricated in three sizes. It is more dit5cult to tailor a prefabricated orthosis to
individual sizes and needst and participants mentioned this as a disadvantage of Toeoff- However, once
individual adjustments had been made, participants found ToeOff comparable to or more comfortable than
their original AFO, It is remarkable that six participants preferred the comfort of their prefabricated
ToeOff orthosis to that of their custom-made original AFOs (see section 4-52), while only one participant
preferred the comfort of his origina1 AFO. The lightness of T ' g r e a t l y contrt'buted to these high
comfort ratings. and was noted by most participants as a clear advantage of Toeoff. Several participants
commented that it was so light they often forgot they had it on; others found that it was cooler to wear,
particularly in the summer, because air is able to circulate around the back of the leg.
Function
In terms of bction. participants' comments idenm a tradeoff between the reduction in ankle
support and increase in ankie movement provided by ToeOK Users did not report actual incidents of
inversion or instability when walking with ToeOff, but for several people the reduction in ankle support
compared to their o r i g i d AFO contributed to lack of confidence when walking on uneven ground. These
individuals considered ToeOff less dependable for uneven ground, and resorted to walking more dowly
and wefblly, using a cane, or switching back to their original AFO- On the otiler hand, cIifEerent users
found ToeOff more efkctive for watking in general, because of tile increased ankle movement that is
allowed-
In general, users found that it was easier to climb stairs when wearing T e , but easier to go
down stairs with their original AFO. The fact that users consistently expressed greater diffi.culty with
ToeOff when descending stah has d k c t clinical application That is, the cIinician wiII want to advise
clients that they may find it more difficdt to go down stairs with ToeOff and that tiley should be carem
particularly when first trying stah with the orthosisosis The effect of wearing ToeOf€on the activity of
stairclimbing could probably not have been predkted by its designers, which makes user reports and
eqlanations very valuable.
Since ToeOff does not encase the ankle and incorporates a flesible sole plate, more natural gait is
advertised in the marketing brochure (International Orthopaedic Marketing, 1998). Severzl participants
did report a more natural gait with ToeOff- Two persons found it easier to achieve a heel to toe motion
after foot contact; two others reported that they did not have to circumduct their Ieg as much, and that
their affected foot was straighter when walking. However, one individual reported more difficulty
achieving heel to toe motion at foot contact with T- These subjective reports could be M e r
investigated using gait analysis: gait analysis of each participant would allow direct comparison with
individuat observations and comments,
ToeOffwas designed to provide an additional power burst at toe-off, when the orthosis springs
back to its natural codormation, thereby consenting energy for the user. TNs effect has yet to be
substantiated by gait analysis. Most participants had noticed the spring effect of the ToeOffsoIe plate,
although this was not the focus of discussion. Two people found the spring effect disconcerting, and one
found it insulXcient- Other participants found the spring eff'ective, but this factor did not stand out for
users as a clear advantage of Toeoff. Designers or biomechanists would likely consider the dynamic
properties of ToeOK as the most notable aspect of tius new devicece However, fkm a user's perspective,
the ligl~tness and colour of ToeOffl both the result of the new materials employed in its design, dong with
the impact of ToeOtron activities of walking on different surhces, stairclimbing, and application, dese~~e
the most discussion,
Application
Participants had more difXiculty applying the anterior fitting ToeOff compared to their ori-
AFO, which attached posterior to the calf. This difficulty was compounded because most individuals only
had one hctional han& which for some participants was their nondominant hand, Lengthening the
straps facilitated application, although some individuals still had difficulty putting their brace and foot
into the shoe, and bringing the fiont ofthe ToeOff orthosis tight enough to the shin for attachment,
An AFO which is difficult to pat on is less Wrcly to be worn However, usage time of the ToeOff
AFO was statistically greater than that of the original AFO, so the diflicuIty was not so great as to prevent
ToeOff from being worn. One individual did comment that when she is in a hurry to get ready in the
morning, she wears her original AFO.
User Recommendations
Participants made several recommendations to improve both AFOs they had worn, The main
compIaint with the original AFO was that the hinge at the back often caches on pants and long dresses-
which is both disconcerting to balance and expensive if clotlung requires repair or replacement, One
individual had requested a piece of leather to be attached to the brace above the lunge; this leather piece
covered both the binge and gap, when the I h g e was open, preventing the brace fiom catching on
clothing. Other participants in the same focus group found this quite ingenious, and thought it would be a
great improvement to the brace- The other suggestion for the original AFO was to eliminate any
unnecessary material, for e-sample making a hole posterior to the calf, to make the brace smaller, lighter
and cooler.
Recurring suggestions to improve ToeOff were to change the colour to a flesh tone, match the
colour of the padding to the brace, and make application easier. One technique to =litate application
was to lengthen the straps, however individuals stiIL had ditlidty putting their brace and foot into the
shoe, and bringing the anterior part of the AFO close enough to the leg, Other suggestions invoked
W n g more sizes or options for the prefabricated AFO available Participants in one focus group
recommended that making difEerent widths ofToeOffavailable would more appropriate& tailor it to
different foot sizes. and alIow persons with narrower feet to wear ToeOff in more types of shoes- Another
individual suggested that this might be accomplished by p-ding a nonstructuraI portion of the sole
plate, wlucl~ could k trimmed as neceSSiLIyeceSSiLIy Finally- Herences in opinion about the ef1Tectiveness of the
spring suggest that the ability to individualize the spring rate wouId be kneficiaL
5.6 Indications and Contraindications for ToeOff
The objective of the clinical assessment was to determine indicators and or contraindicators for
prescription of the ToeOff AFO. Findings fiom each d o n of the clinical assessment are discussed
individuallj*. and then summarized into probable indicators and contraindicators for Toeoff-
5.6.1 Range of Motion
Panicipants who achieved energy savings with ToeOK in terms of PC1 results, demonstrated a
greater range of active and passive ankle dorsiflesion compared to participants in the other three groups-
Participants who demonstrated positive PC1 results with ToeOff also had a greater range of active and
passive hip e~cension, compared to participants in the other three groups. For all other range of motion
measures. there was no clear distinction behveen individuals in the four groups, and considerable overlap
was seen.
The ToeOff orthosis was designed to simulate plantarfle-xion as it springs back to its natural
conformation, However, the orthosis cannot spring back unless it is fim compressed In order to
compress the orthosis, ankle dorsiflexion and hip e~qension are required- Individuals who were abIe to
wear ToeOff but did not demonstrate positive PC1 results may not have been able to d~ciently compress
the ToeOfforthosis to benefit fiom its dynamic properties-
5.6.1 -1 Comparison with Normal Range of Motion
Reference values for normal active and passive range of motion of the ankle, knee and hip are
reported in Tables K 1 and K-2 (Appendix K), All participants were within or above reported normal
values for active and passive ankle piantarfle-xion, with the exception of one individual (S3) who was
slightly below the reported range of normal active pIantarfIexioa In contrast, all participants were well
below reported normal values for active and passive ankle dorsiQtxion, with the exception of one
individual (S 16) who attained nornlal active dorsiaexion according to the Iowest reported value, Two
individuals (S 12, S 16) were witbin the n o d mge of active knee flexion, according to the lowest
normai values reported, while all individuals were w e l l below the reported normal range of passive knee
flesion. Six individuaIs (St, SS, S 10, S 12, S 14, S 16) had normal active and passive knee estension,
while one individual (SS) had normal passive knee e~qension only. Six individuais (S2, S5, S9, S 12, S 15,
S 16) demcinstcrrd normal active hip flexion, according to the Iowest reported normal value, but no
individuals had normal passive hip flesion- Finally, sis individuals (S5, S9, S LO, S 12, S 15, S 16) showed
normal active lup extension, according to the lowest reported normal vaIuey but no individuals showed
normal passive hip extension
5.6.1 -2 Summary of Range of Motion Findings
These results of range of motion testing do not allow clear ditrerentiation of participants who
achieved positive PC1 results with ToeOE However, participants who achieved normal range of motion
were generally in the group that demonstrated positive PC1 results with ToeOff, or in the group that
showed no dserence, in terms of PCL behveen orthoses. With the exception of the individual (S 11) who
used a walker and therefore may have been able to employ nonstandard joint kinematics when walking, all
participants who demonstrated positive PC1 results 114th ToeOff had normal active range of motion in at
least one direction, either flexion or estension. of one of the joints tested. Furthermore, the two
participants who demonstrated negative PC1 results did not have normal active range of motion ofthe
affected ankle, knee or hip.
5.6.2 Muscle Strength
Because the TaOEAFO was dm-gned to enhance firor-ted plantadexion, it was expected that
individuals with Iimited ankle plantarflexor strength on the & i e d side would benefit most h r n T e
but this was only parthlly supported by the dynamometer measurements. One individual who showed
negative PC1 results with ToeOBI(SS), and one individual who showed no change in PC1 with T o e
(S 10). demonstrated ankle plantarflesor strength which w a s higher than that of 6 of the 7 participants
who showed positive PC1 results- These two individuals may have been able to employ suf6cient natural
plantarfle~or strength with their original hinged AFO to genemte power at push-off? so that the energy
storing and release which tile ToeOff AFO alms to provide at push-off did not make a noticeable
difference. However, one individual with good plantarfle-sion (S12), also demonstrated positive resuits
with Toeoff. and two individuals with weak plantarflesion (Sl, S2) did not show positive results with
Toeoff-
The two participants who showed ;regathe PC1 results had notably lower knee extension and hip
£lesion strength than participants who showved positive PC1 results with T- The single exception is
the individual who used a walker (S 1 l), and demonstrated low muscIe strength of all muscle groups, but
achieved positive PC1 results with ToeOK Inadequate knee extensor strength may be related to lack of
success with ToeOff, Knee estensors are usually active in preventing knee collapse during stance phase
(Winter. 1991). and to control the natural heel to toe motion which occurs at hed contact- In the absence
of -cient knee e~qensor strength, a shortening contraction of the hip elTensors can substitute for these
functions. Howvewer, the hip estension strength of the hvo participants who demonstrated negative PC1
results was in the Iowver range of that exhiiited by participants showing positive PC1 results, therefbre they
may have been unable to compensate suflicientiy. Because of low knee elqensor strength and 3ack of
adequate compensation, the two individuaIs who sl~owed negative PC1 results with ToeOE may have had
dif£iculty achieving a consistent heel to toe motion at heel contact, which would have made it difficult for
them to benefit from the dynamic properties of Toeoff- In the focus group, one of these partkipants did
describe dficulty achieving Ireel to toe action with ToeOK Inadequacy of hip flexor strength could also
be responsible for these inability to take advantage of the energy-saving properties which
ToeOff is intended to pm*& At the end of stance phase, a strong contraction of the hip flexors is
required to reverse the motion of the hip and to begin pull-off, Inadequate strength of the hip flexor
muscle would mean that the participant could not afford to estend the hip beyond the point ofestension
wluch he or she could comfortably reverse, which, in turn, would not enable the subject to compress :he
ToeOB AFO.
The two individuals who demonstrated no rcal change in PC1 results between orthoses had good
muscle strength of the knee estexwrs, hip flexors, and hip e.stensors, demonstrating values which were
higher than some participants who had positive PC1 results with ToeOf£ A possiile explanation for the
fact that two individuals demonstrated no change in PC1 results with ToeOff is that they were using these
three muscIe groups to compensate for ankle muscle weakness? such that the increased plantarflexion
moment wluch ToeOff is intended to provide did not make a noticeable cWerence-
The individual with multiple sclerosis (S 14) wore a hinged orthosis for approximately one month
before trying the ToeOff AFO, This individual wvas unsatisfied with both orthoses, is no longer wearing
any orthosis, and probably Ims made accomodations to her gait using her very limited muscle strength that
cannot be carried out when wearing any orthosis.
5.6.2.1 Comparison with Normal Muscle Strength
Reference values for hand-held dynamometer measures are reported in Table IC3 (Appendix K),
with the esception of ankle pIantarfIesion, for which hand-held dynamometer reference values could not
be found- In general, strength of all muscle groups on the affected side were much lower than normal
values matched by age and gender- Ankle dorsiflesor strength on the afEkcted side wvas well below normal
strength for all participants, One participant (S9) had above normal knee flexor strength, compared to the
value reported in Backman, lohansson, Hiiger, Sjoblom, and Henriksson (199% but not that in Andrews,
Thomas and Bohamon (1996)- In terms of knee exlension, one individual (S5) was above her matched
normal knee ehlensor suength, and two o&ers (SQ, S10) were close, compared to the values reported by
Biickrnan (1995) but not those by Andrews (1996). For hip flexion, two individuals (SZ, S16) were above
their matched normal strength values, compared to the n o d values reported by Andrews (1996) but not
those by Biickman (1995)-
5.6.2.2 Summary of Muscle Strength Findings
The SLK individuais who showed normal muscle strength ofa singie affected muscle group either
demonstrated positive PC1 results with ToeOE or no difEerence in PC1 results between orthoses.
Individuals who showed negative PC1 results or were unable to wear ToeOff did not approach normal
rnuscIe strength of any afFected muscle group, and demonstrated particularly low strength values of the
knee eA?ensors and hip flexors. Thus individuals who performed best with ToeOEdemonstrated muscle
strength deficiencies, yet eufuiited su£6cient control and/or substitute muscle function to take advantage
of the dynamic properties which ToeOEis intended to provide-
5.6.3 Spasticity
The presence of moderate or severe spasticity are reported as contraindications for ToeOff on the
product brochure (International Orthopaedic Marketing, 199s). hourever the level of spasticity which can
be accomodated by T o m is not known, A simple clinical test which could differentiate candidates with
too much spasticity from those whose spasticity can be acconmodated by TodXwould be usefirl-
There was no obvious difference, in t e r n of Modified Ashworth Scale ratings, between
participants in each of the four groups. One of the participants who achieved positive PC1 results received
the same Asl~worth grade as the participant (S3) who w a s unable to wear ToeOff due to ankle
pIantarflexor -city- Although spasticity is velocity dependent, the Ashworth scale may not be
d-ciently sensitive to detect dil3erences in people who respond with a contraction at a lower stretch
velocity. The individual (S3) who was unable to rvear ToeOff due to plantarflexor spasticity may have
responded at a lower stretch velocity tlwn the individual (S5) who received the same Ashworth grading
but achieved success with Toeoff.
Results from the manual Pendulum Test showed that individuals who were unable to wear the
ToeOff AFO demonstrated fewer osciHations in 10 seconds than the average number of oscillations for
other participants, indicating that these individuals had greater knee extensor spasticity- However, some
individuais (S1, S9, S11, Sl5) who showed positive PC1 &IS had very simbrvalues to those who were
unable to wear ToeOff, indicating that the manual Pendulum Test does not clearly identi@ participauts
unable to wear ToeOfE
One individual (S6) was unable to wear T o e d u e to spasticity of the toes- This type of
spasticity was not assessed by either of the clinical measures here, but could be assessed visually- In
general, any candidate with persistant clawing of the toes will Wrely experience considerabIe dixomfort
with ToeOffl because the sole plate is very st i f f and curves upwards at the metatarsals,
In summary, Aslworth ratings of up to 2 are not a wntraindication to the s u m wearing of
ToeOE, whereas clawing of the toes may be.
5.6.4 Other Clinical Measures
There was no real difference in two-foot stability or somatosensory h c t i o n between the four
groups. Individuals who were rated as impaired in one, two, or t h m of the tests. in some cases. were still
able to achieve positive PC1 results with Toem These clinical measures did not rnerentiate participants
who showed positive PC1 results with ToeOff from those who sl~owed no clmge or negative results,
5.6.5 Summary of Indications and Contraindications for ToeOff
Results of the clinical assessment, combined with relevant focus group data have been
sum-zed into a list of indications and contraindications for ToeOff (Table 5-1)- This table can be used
by ciinicians in assessing whether a client is a potential candidate for ToeOff. The first six
contraindications were derived from rating form and focus group data along with visual observations of
spasticity, while the latter five were derived from the clinical assessment measures,
The ToeOff AFO may be prescn'bed for footdrop resulting fiom neutological conditions- Within
this study, nine participants with footdrop resulting fiom stroke, one participant with peroneai neuropathy
due to trauma, and one participant with a back injury and ensuing plantarflexor weakness, trialcd the
ToeOff AFO, In terms of the PC1 results, participants with all thfee conditions achieved success with
ToeOff. However, in terms of gait analysis and the individual's subjective report, the ToeOff AFO was
slightly less effiective as a phntarflexion substitute for the @cipant with a back injury than his original
plantarflesion assist AFO. It is likely that ToeOff was inadequate to support this participant's weight, and
therefore did not provide &dent resistance against dorsiflexion or spring efFect a t push-& The Toeoff
AFO appears to be an insugicient plantadlesion substitute for individuals weighing more than 95kg
The ToeOff AFO may be indicated for cIients with good mediohteral ankle stabiIity who present
with compiaint or evidence of ankle muscle atrophy with their current thermoplastic AFO- In the focus
group discussions, several participants were pleased by the additional ankle movement provided with
ToeOK One participant, for example, reported muscle development around the ankle as a result of using
ToeOff, after having worn her original AFO for almost two years.
Age may be a hctor in accomodating to Toeoff, with younger users able to capitalize more on
the espected benefits of the ToeOff design, because their motor control systems are more easily adaptable,
and because ankle stability or fear of falling is not a concern, The two youngest participants in the current
study performed very well with Toeoff- At 17 years of age the only child in the current study expressed
immediate preference for the ToeOEAFO upon initial fitting, achieved positive PC1 results at both
walking speeds, showed an increase in the mean percentage ofwaking time spent in physical activity on
the ActRe. rated the ToeOff AFO consistently higher on all dimensions of the two rating forms. and stated
preference for ToeOff in the focus group discussion, The second youngest participant was 43, and also
espressed immediate preference for ToeOff during individual monitoring and throughout the focus group
discussion, Tlus individual demonstrated no change in PC1 at comfortable walking speed but a reduction
in PC1 at fast walking speed, and rated the ToeOff AFO consistently higher on both rating forms, The
only negative result for this person was the Act& on wluch she displayed a decrease in physical activity
with Toeoff. However, overall this person performed better and was much happier with the ToeOff AFO.
Because both of these individuals performed very well with Toeoff, additional testing of the ToeOff AFO
wit11 both children and young stroke survivors is recommended.
All other participants were over 50 years of age, many of whom also achieved positive results
with ToeOE- thus age alone is not a contraindication for this new orthosis, For example, at 73 one
panicipaat adjusted to ToeOff immediately, achieved the greatest reduction in PCI at comfiortable walking
speed, rated ToeOff consistently better on both the comparative and noncomparativt forms, and expressed
preference for TwOff in the focus group discussiotl Although this person showed no change in PC1 at
fast walking speed and no change in physid activity on the ActRe- his preference is clearly for Toeoff
and the demonstrated decrease in PC1 at comfortable walking speed was remarkable. While elderly
persons can acl~ewe success with To-, balance, stabiIity and fear offalling are important issues for the
elderly population. and the reduction in ankle support provided by ToeOffwas highlighted within the
focus group discussions, For waking on uneven ground, users indicated preference for their original AFO
on both the comparative and noncomparative rating forms, and these ratings were substantiated by the
focus group discussions. For these reasons, use of T e w i t h persons who M e r fiwm balance problems
or feelings of instability is not recommended
Results of the clinical assessment indicate that persons with limited ankie dorsiflesion or hip
extensions range, Cut-off range of motion and muscle strength values arc given as guidelines, based on
evidence within the current population tlnt participants below these levels either did not achieve success,
in t e r n of PC1 results, with the ToeOff AFO, or were unable to wear this orthosiw In general, a client
with limited ankle dorsiflexion or hip esqension range, or Iimited knee extensor or hip f l e s ~ r strength,
wiIl have difficulty taking advantage of the espected dynamic properties of T- A client whose ankle
position is at neuual tluoughout push-off will not be able to benefit from the intended design of ToeOffl
because the orthosis cannot spring back unless it is first compressed- In order to benefit from the expected
dynamic properties of the Toeoff AFO, the client should currently exhibit consistent movement into
dorsiflesion at push-off, or should be able to be trained to do so.
Due to the limited sample size in the current study, h h e r testing to verifj. these findings is
indicated, As the number of individuals to trial the Toeoff AFO increases, it may be possible to elucidate
M e r and more refined ceco~errdations.
Table 5.1. Indications and Contraindications for the ToeOR AFO
Indications for TocOff
Contraindications for T d f f Persistant cIawing ofthe toes
Necd for mcdiolataal anldt support
DXcuIty or fcar offslling when going d m stairs
Inability to attach an AFO posterior to the calf
Inability to d o d e x past neutral at push-off
Limited ankle dotsiflexion range Guideline Valuesfor Erclusion: 4 Actfve range less tban -So, when
measwcd in supine position with the hip and knee flexed
0 Passive range less than 5O, when measured in supine position with the hip and knee f l e d
Limited hip extension range Guideline Values for EicIusion: 9 Active range icss than -So, when
measured in supine position with the hip and knee f I d
6 Passive ankle doniacxion less than 5', when measured in supine position with the hip and kuee flexed
Weak knee extensors Guideline Values for &dusion: + Kn~nee extensor strcngth of less than 9 kg
force, when measured at the ankle in seated position with the knee at 90"
Weak hip fie-wrs
Guideline Values for Ejccfusion: 4 Hip flexor strength of less than 9 kg force,
when m d in supine position
CHAPTER 6. Conclusions and Recommendations
6.1 Conclusions
The ToeOff AFO is a dropfoot orthosis which was designed to store energy during midstance and
reIease it at toe-off; t h e e mnse~ng energy for the user- The current study invited experienced users of
AFOs to trial the Teorthosis , combining traditional Iaboratory techniqws with measures of daily
activity levels, as wefl as soliciting user feedback about the two orthosesOSeS
With a sample size ofonIy 11 participants, the statistical evidence tbat participants pcrfomed
better with ToeOfFis limited However, where statistical signiscance was achieved, an advantage of
ToeCKwas indicated Looking at the absolute number of participants who achieved positive: or negative
resuIts with Toeoff, more individuals achieved positive results, both in the laboratory and during daily
activities, as well as indicating overall pderence for this new orthosis:
Combining the PC1 d t s at sekelecteci comfortable and fast walking speeds, seven participants
showed energy savings or probable energy savings when wearing the ToeOff AFO, two showed no
difference between orthoses, and two showed increased energy costs with ToeOK
Four participants were able to increase the distance walked in six minutes, when wearing To- five
showed no difference between orthoses, and two decreased the distance waked with T m .
OveraU, participants deaea& the mean percentage of waking time spent resting as a xnain activity
(p=.032), when wearing the ToeOEorthods. This suggests that participants were able to increase
time spent in other activity categories, when wearing ToeOff compared to their original AFO- Paired
t-tests on the mean percentage ofwaking time spent in other activity categories found a statistically
significant increase in participation in nixreation and Ieisure activities only p.021).
The mean percentage of time spent wearing ToeOffwas statistically greater than wearing time of the
original AFO (p--.021), which may suggest increased user satisf8ction with this orthosis.
In gene& individuals who- showed a deaease in energy cost when wearing T e , evaluated by
the walking tests and calculation ofPCI, were able to increase their ph*d activity during a t y p i d
day, and vice versa-
Participants rated the ToeOflEorthosis significantly higher than their original orthosis, in tenas of
comfort @--036)- For the chosen alpha lewd @=-OS), the median rating of the ToeOfforthosis was
not statistically different from that of the original orthosis on any ofthe other dimeasions easiYamined.
Combining the results of comparative and noncornparative rating forms, more participants indicated a
preference for the ToeOff AFO in terms of comfort, walking on eve^ ground, going up Stairs. o v e d
fbnction. appearance. and overall rating- For walking on uneven ground, going down stairs, and
application, more panicipants indicated a pteference for their original AFO- Focus group discussions
substantiated these overall preferences, and pmrOVlded valuable insight ixito individual conte13s.
thoughts, and ideas-
Gait analysis of two participants did not iind an inincrease in ankle power of the affected side at push-
o E However. one of these individuals demonstrated increased energy costs with ToeOff, in terms of
PC1 resdts. and the other's original AFO was a plantarflexion assist orthosis. Further gait analysis of
individuals who demonstrated energy savings with ToeOff and had an original dropfoot orthosis is
recommended. to determine whether Toem does provide an addihod power burst at push~f f for
these individuals-
The majority of participants in the current study demonstrated more positive results with the
ToeOff orthosis, compared to their original AFO- Of the two participants who showed negative PC1
results, one thought that he Imd become too dependent on the support and characterisrics of his original
AFO, which biased his results in favour of his original AFO. The other participant did not demonstrate as
negative results, in terms of percentage change, expressed satidkction with ToeOff in the focus group, and
is currently alternating between the two orthoses, As with any assistive devicep the appropriateness of the
ToeOff AFO should continue to be assessed on an individual basis.
6.2 Limitations of the Study
As with any research project, there are several hitations to this study- F ' i the small sampie
size and high individual VariabiIity of participants makes it difficult to generalize d t s to other potential
candidates for T- Participants were a seIf4eIected group ofwilLiag and highly motivated volmteers,
many of whom ?ravelled long distances to participate iu this research, These high levels of motivation
may have allowed participants to capitalize more quickly on the energy savings provided by TaeOff; and
to take advantage of this conserved energy in daily activities-
Secondiy, although participants presented in stable condition, there may have been improvements
or deteriorations in physical and mental heaith which aEiected prformance on the laboratory and ActRe
measures. While changes in physical health would affect motor performance directIy, changes in mental
health. for esample a diBerence in the Ievel of depression, anxiety or motivation, could also s e c t
performance on the walking tests and ability to engage in dailyactivitie.~~ On average, post-testing was
performed one month after initial testing, which is sdicient time for changes in general health and well-
being to have taken place- The individual with peripheral neuropathy (S12) was beginning to recover
dorsifleuion fhction by the time of post-testing, and this may have biased results in favour of Toeoff.
However, doniflesion has not been correlated with gait speed @ohanno& Andrews, & Thomas, 1996), so
this is not expected to have been a major influence on walking test performance,
Gait analysis was limited to two dimensions and did not assess motion in the fiontal plane, which
could have resulted in underestimation of power and work. For example, if the Iower limb was laterally
rotated, the contribution of the hip adduaors to hip flexion would have been inappropriateIy a t t n i to
the hip flexors- Homer , the majority of the work of walking is performed in the sagittal plane, since the
objective of ambulation is to support the body against gravity while moving it forward in the plane of
progression (Eng & Winter, 1994). Furthemore, no participants in the current study demonstrated
markedly rotated limbs, and identical testing procedures should have produced similar underestimations
with each orthosis,
Since participants performed the same walking tests on two occasions, a learning &ect may have
biased d t s in favour of ToeOK When tests are performed on two consecutive days, an improvement of
15% has consistently been found on the second day (Steele, 1996). Reports of I d g &kt after more
than one day were not found in the Iiterature- Since retesting was performed an average of one month
after initial testing the learning &ect is expected to be minimal. Furthefmore9 participants were given a
practice walk at each speed before initial testing, to accommodate the volunteer to the environment and
minimize the learning effect Finally, six of the eIeven participants in this study had previoudy
volunteered for other research conducted in the School of Rehabilitation Therapy at Queen's University,
in tvhich they were required to perform the same walking tests on at least two occasions
The ActRe has been validated as a reliabIe tool to assess energy consemtion, and was found
sensitive enough to detect the effects oftreatment (Gubcr & Fum. 1992a; Gexber & Furst, 1992b).
However* the Act& has not previously been used with the nurent popdation, so reliability values are not
specific to persons who Iuve dered a stroke* peripheral ne~opathy~ or back inlury- The Act& has been
used with persons with rheumatoid arthritis and chronic fatigue syndrome, as well as controls (Gerber &
Furst. 1992a; Gerber & F m , 1992b); since diagnoses in the current study were similarly chronic, there is
no reason to eqxct tlut variability of ActRe results would be greater with the current population-
Accomodation time to the new orthosis was individually monitored such that participants
themselves determined when they felt they had adjusted to the ToeOtf AFO, and whether any further
modifications were necessaq. However, it is possible that a longer accomodation period wodd have
produced more positive results with ToeO£€'. since most individuals bad worn their original AFOs for
more tlmn one year. and may not yet have fdly adjusted to the strikingIy different orthosis-
A limitation of the focus groups is that all participants were Caucasian; persons of different
cultural backgrounds might express different values and preferences. For esample, while many women in
the current study espressed a preference for a flesh-doured AFO, to reduce visibility, a woman with dark
skin might find the flesh coIour more obtrusive-
The appropriateness of strength testing with a neurologically impaired population is an issue of
contention (Bohamon, 1989). Measures of voluntary muscle strength obtained in the clinical assessment
may differ from the effort of which participants are capable under dynamic conditions. Depending on the
elqent of neurological impairment, some participants may have had more voIuntary control than others.
This consideration may partly explain the die6culty in determining ch-cal indicators for success with
ToeOfE
6.3 Suggestions for Further Research
Followup with the current p u p of participants would determine whether cwrent energy savings
with T e a r e permanent, as well as which AFO(s) each participant has chosen to wear- Due to the
limited sample size in this study, it is desirable to test ToeOff with more individuals, using the protocol of
the present study, For example, it would be interesting to trial Toeoffwith persons whose original AFO
is rigid and does not aiiow any plantarflcuion, to see i f T ~ p m v i d e s an even greater energy savings
under these circumstances-
In the h u e , additional gait analyses of individuals wearing ToeOffand representing the range
of conditions expected to benefit &m a dropfoot AFO are recommended These analyses would
determine whether ToeOff provides an additional power burst at push-off, and what other gait
modi6cation.s resuit Ifthe analyses were sufficiently reveaIing, it is possible that focussed gait training
would increase the effdveness of the orthosis- Finally, the roles of spasticity and muscle strength in
determining the success of T o e usage also deserve further study-
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Appendix A AFO Pictures
Figure Al. Pictures of thermoplastic hinged dropfoot AFO
Figure A2. Pictures of thermoplastic hinged plantarflexion assist AFO
Figure A3. Pictures of ToeOff AFO
Appendix B. Consent Fwm
School of Rehabilitation Therapy Faculty of Health Science
Queen's University Consent Form
Assessment of Toeoff, a new Ankle-Foot Orthosis for footdrop
Invitation to Participate
You are invited to participate in a research study to assess ToeOfltl a new ankle-foot orthosis for footdrop.
Basis of Subject Selection
The reason you are being asked to participate in this study is because you were previously prescribed an ankle-foot orthosis for footdrop and have been using this orthosis for atleast three months. In addition, you are able to walk for atleast 15 minutes, with rests, and to complete a log of daily activities, with or without assistance.
The purpose of this study is to determine the effectiveness of the ToeOff orthosis compared to your original foot brace.
EjipZimution of Procedures
You will be asked to complete a brief survey of demographic information Following that, you will perform two walking tests of6 minutes each. Your heart rate will be recorded by a small instrument fastened to your chest. The first walking test will be at your fm waking speed and the second at your normal wallring speed. You will rest between each walking test. You will take part in one assessment that you will complete at home by filling out forms on which you record your daily activities for two consecutive weekdays. During these two days, you will complete the forms at lunchtime, dinnertime, and bedtime. You will be fitted for a ToeOff orthosis which you will wear for at least one week or until you have accornodated to it and any necessary adjustments have been made. You will repeat the two walking tests with the ToeOff orthosis, and fXI out forms recording your daily activities for two consecutive weekdays. You wiIl visit the Physiotherapy Clinic at Queen's University, where the flexibility and muscle strength of your affected ankle, knee and hip will be assessed, as well as spasticity, ankle stability and somatosensory hction-
Finally, you will take part in a group discussion with other people who have also worn the ToeOff orthosis-
Potentiai Risks and Discomforts
There are no known.risks associated with the study that are not present in your usual daily activities,
Po~ential Benefits
You will be able to keep the ToeOEorthosis. You may be able to walk better with this orthosis. The results of this study may help firture orthosis wearers.
All testing will be done at no cost to yourself The TaOfforthosis will be provided to you at no cost, and you will be reimbursed for your travel costs to the testing sessions.
You will be assigned a number that will be used in all records. Any information obtained in this study may be published in appropriate journals or presented at professional meetings. In such publications or presentations, your identity will be kept strictly confidential.
Withdrawal from the Stz&
Your participation in this study is voluntary. If you decide to participate, you are free to withdraw fiom the study at any time.
Offer to Answer Questrions
Please ask any questions which you have. If you think of questions later, please contact one of the investigators listed below.
Subject Statement
I have read and understood the consent form for this study. I have had the purposes and procedures ofthe study explained to me. I have been given sufficient time to consider the above information and to seek advice if1 choose to do so. I have had the opportunity to ask questions which have been answered to my satisfaction. I am voluntarily signing this form. I will receive a copy ofthis consent form for my records-
Eat any time I have further questions, problems or concerns, I will contact one of the following persons:
Servane Mason Dr- Tanya Packer Dr- Sandra Olney (6 13)542-3740 (613)545-6085 (6 13)545-6102
By signing this consent form I am indicating that 1 agree to participate in this study.
Signature of Subject Date
- -
Signature of Witness - - - -
Date
Statement of Investigator
I have carefblly explained to the subject the nature of the above research study. I certify that, to the best of my knowledge, the subject understands clearly the nature of the study and demands, benefits, and risks to participation.
--------------- -CII-----
Signature o f Investigator Date
Appendix C.
Name:
Gender:
Address:
Phone:
Subject Information Form
SUBJECX'S RECORD FORM
Subject #:
Contact Name: Phone:
Group: Start date: i 1
Age: Date of birth: --- / i
Occupation: Education:
%or Activity Level (sedentary to very active):
Smoking:
Alcohol Consumption:
Date of onset of stroke: / I
Time since on set of stroke:
Side affected: Dominant side:
Usual waudng aid:
Medication:
6
Physician: Name: Address:
Phone:
CT Scan information:
OTHER DISEASES: HyperteMoo:
Heart disease:
Diabetes:
Obesity ( B m :
PAST HISTORY: FaiIs:
Surgery:
PHYSICAL EXA2VIINATION: Lower Limbs Sensation: Superfiuak
Dee~:
Skin integrity:
Joint pain:
Coordination:
Balance:
OTEER RELEVANT INFORJ!blATIOE Language: Aphasia: Dysarthri3:
vision: Hemianopsh: D iplopia:
Haring Deficit:
Memory:
Orientat ion:
Bowel control:
Bladder control:
Appendix D. Clinical Assessment Form
. I W J I for IOM Study
Name:
Subject #r
Date of Assessment:
Date of Birth:
Date of Stroke:
Side of Stroke- Left / Right
RANGE OF MOTION (Goniometer)
I Joint Movement I Position-for Testing Active Passive I ROM I ROM
Ankle
Knee
Hip
plantar flexion
dorsi flexion
supine
supine hip flexed
supine hip extended
Flexion
Extension
Flexion
Extension
side lying (hip in extension)
sitting
supine
side tying I
MANUAL MUsCtE TESrnG (Hand Held Dynamometer)
Joint
Hip
I plantar flexors 1 supindong sitting I I 1 1
Ankle
Knee I sitting with knee at 90 1
Muscle Group extensors
extensors I sitting witb knee at 90 1
dorsi flexors
Modified Ashworth Scale Ankle plantar flexors
Position for Tcsting
supine with hip and knee at 90, foot on shoulder oftester
supindong sitting
SPASTICITY
Results
Pendulum Test Position: Sitting with leg tiee and not touching the floor. Test: Client relaxed with no shoe, no brace. Extend knee to 90 and drop.
I Measurement # 1 ( # of osciiiations in 10 seconds I Measurement # 2
Am~litude of hitid Oscillation Final Resting Position
goniometric measure of flexion on first oscillation
Measurement # 3
easurement #2 Measurement #3
angle of rest when oscillations completed
Stability
ANKLE STABILITY
intact / impaired
SOMATOSENSORY TESTING
Light Touch (foot) intact / impaired
Pin Prick (foot) intact / impaired
Proprioception (great toe) intact I impaired
Appendix E. Act- Instruction and Data Collection Forms
Instructions for Activity Record -- -- -
The purpose of this quesliormaire is to help understand what you are doing and how it affects h ~ w you feel. To make remembering easier, it is recommended that you fill out this questionnaire at lunch, dinner and bedtime, (ether than the whole day at one lime, It is important to be accurate.
Step 1 In the activity space, write the activity that you feel best describe8 what you were doing during that half-hour of the day, If what you were doing takes b g e r than one hat-bur, write it again tor as long as you continue to do the activity. If you were doing more than one thing during the haw-hour, write the main thing you wem doing in the activity space.
Step 2 Answer questions I to 10 for each haw-hour time period by putting a circle around the number you feel
Step 3
Is the best answer to the question, You do not need to answer the questions for sleep,
In question 5, an aclMty may be difficull to do tor several reasons, For example, i! may be difficult physically wMle you are doing il Or, Y may be dMicuQ because it requires a lot ol advance planning or preparation, or because It takes a long time, or Is very tiring or palnkl.
In question 6, some lr\lng can be meaningful whether you like it of not,
In question 9, circle 1 (Yes) il you slopped to test for a 5 or 10 minute break during the half-hour activity petiod; or circle 2 (No) W you did the activity lor the lull half-hour without a resl break,
.-- -
Fill in the cutegory column with the two-letter code from the list on the right lhat best describes what you were doing dwing that halthour of the day,
Categories
Rest (RE) - rest periods taking one half-hour or longer
Self-Care (SC) - personal care activities incllrding dress in^, grooming, exercises, normal meals, showering, or other similar activities
Preparation or Plannina (PP) - time spent preparing to do an activity or planning Wrr arrd how to do your dally or weekly activities
Hourehold Aclivitka (HA) - cooking, cleaning, mendkrg, d'wplng for or putting way proctries, gardening, or other similar activities
Work (WK} - paid or volunteer activities in or out of the home, school wwR, wriUng paws, attending classes, studying, or other similar activities
Recnatlon or b h u n (RL) - ~obbibs, TV, games, feading (unless done during short rest breaks), sports, out-krwmeaJs, movies, adult education classes, shopping, gardening, talking with friends, or other similar activities
Tnmportrtion (TR) - (ravelling to and from acUvHies
Traatment (R)o- doctw or therapy appoinlrnents, home exercjse, etc,
S b p (SL) - when you go to bed for the night
Activity Record Page 1 of 6
Jame Day/Date
uest~on 4 Question 5 I uestion 6 Question 7 Question I * Morning Question 1 Quesliocl2
During This
T i m I War
Mostly ---- Activity 1 =Lying
Down
UIIk Walking, 3GSome tifling or 4=A Lol Movine
I=Nol At MI l=Not At All 1 =Not At FI 2=Vefy 2=Vcry 2=Vwy Liltk llllle litllr
~ ~ S O I ~ Q 3nSome 3tSom0 4=A Lot 4=A Lo1 4=A Lol
I Around I
Appendix F. Noncomparative and Comparative Rating Scales
Noncomparative Rating Scale
Date:
Subject Code:
Orthosis: Original ToeOfF
Likert Scale Ratings:
I will be going through a list of brace characteristics or functions. For each topic, please rate your satisfaction with your X brace on a scale of 0 to 4, where 0 is least satisfied and 4 is most satisfied:
Walking on Level 0 1 2 3 Ground
Walking on Uneven 0 1 2 3 Ground
Going Up Staris 0 1 2 3
Going Down Stairs 0 1 2 3
Overall Function 0 I 2 3
Appearance 0 1 2 3
Application 0 I 2 3
Overall 0 1 2 3
Comparative Rating Scale
Date:
Subject Code:
Preference Ratings:
I will be going through a list of brace characteristics or functions. For each topic, please tell me whether you have a preference for one of the two braces you have worn, or no preference.
Comfort:
Walking on Level Ground:
Walking on Uneven Ground:
Going Up Staiis:
Going Down Stairs:
0 verall Function:
Appearance:
Application:
Overall:
Original
Original
Original
Original
Original
Original
Original
Original
Original
ToeOff
ToeOff
ToeOff
ToeOff
ToeOff
ToeOff
ToeOff
ToeOff
ToeOff
No Preference
No Preference
No Preference
No Preference
No Preference
No Preference
No Preference
No Preference
No Preference
Appendix G. Focus Group Interview Guide
INTRODUCTION
Good afternoon and welcome to our session. Thank you for taking the time to participate in our discussion todoy. As you know, my name is Servane Mason and I am working with two professors in the School of Rehabilitation Therapy, Dr. Olney and Dr. Packer, on a research proiect to evaluate a new type of an kle-foot orfhosis called ToeOff. You have each been fitted with a ToeOff brace, and we are very interested in hearing your feedback.
We have invited you here today to share your perceptions and experiences with ToeOff. You were selected to participate in this study because you had already been wearing an ankle-foot orthosis. Since you already have experience wearing a foot brace, you will be able to tell us what you like and don't like. We are interested in your views because they will help us make recommendations to future patients, as well as to the companies that make foot braces.
We will be discussing your experiences with the ToeOff brace, and how you feel about this brace compared to the brace you wore previously. There are no right or wrong answers but only different poinh of view. Please feel free to share your point of view even if it differs from what others have said. Keep in mind that we're iust as interested in negative comments as positive comments, and that negative comments are sometimes the most helpful.
Before we begin, let me go over some ground rules. We are videotaping this discussi0.n because we don't want to miss any of your comments. The video will be viewed only by myself and my supervisors and will be destroyed after we finish analyzing the data. Only one person should talk at a time - if several people are talking at once the tape will be difficult to understand and we'll miss some of your comments. Although we will be using our first nomes today, any reports we write up will not mention names and your identities will be kept completely confidential.
Our session will last about an hour and a half, and we will not be taking a formal break. Please feel free to leave the table if you need to use the rest rooms, which ore down the hall and around the comer, but please do so quietly.
Ok, let's begin ... I've placed name cards on the table in front of you to help us remember eoch other's names. Why don't we start by introducing ounelver and where we're from.. . (thanks to Krueger, 1 988 p80-8 1 )
TOPlC 1 - Irnpocfant Issues in AFO Design
Let's start by going around the room one at time and imagining you've been given your own personal designer to make a foot brace for you. What instructions would you give her?
[Probes: What features are important to YOU? What would you like to be able to do with the brace? What would you like the brace to look IikeZ]
TOPIC 2 - General Impressions of ToeOff
Now let's consider the braces you have had experience wearing. Can you tell me about some of the different braces you have worn3
[Probes: How do you feel about the ToeOff brace$]
TOPIC 3 - Comfort
A few of you mentioned that a foot brace should be comfortable and that ... Let's explore this topic in a little more detail. How comfortable are the different braces you have worn?
[Probes: Do you experience any pain when wearing a foot brace? What makes a brace comfortable or uncomfortuble? How important is the weight of the brace? How long does it take to get used to a new brace?]
-
TOPIC 4 - Function in Activities of Dailv Livina (ADL)
Another issue that came up was how the brace worked during different activities, for example.. . How do you feel your two braces work during your daily activities?
[Probes: walking, stair-climbing, energy/fatigue level, walking on different surfaces Of the different braces you've worn, is there one which you think you walk best with? Are you able to do different activities with different braces? is there any difference in the activities you can do with your original brace vs. the ToeOff brace?]
TOPIC 5 -Aesthetics & Amearance
How important is the appearance of a foot brace? What would you like a foot bmce to look like?
[Probes: What do you think about the appearance o f ToeOffZ colour, shape, style]
- - - - - - - - - - -
Tell me about putting on/taking off foot braces.
[Probes: are certain steps more/less difficult eg. insert into shoe, place foot, fasten straps? How do you find putting on a brace that fits at the front vs. at the back?]
TOPIC 7 - Freauencv of Wear
Each of you has hod the ToeOff brace for several weeks. During this time, how often did you wear the brace?
[Probes: more/less than original brace, Which bmce are you wearing now? Do you alternate between the two braces21
TOPIC 8 - Fitting Process
Tell me about how you would go about getting o new foot brace, and what type of adjustments need to be made.
[Probes: When you get a foot brace, how many visits are required? Do adiustments usually need to be made? What is a reasonable price to poy for a foot brace?]
SUMMARY
Before we close the session, I'd like to ask if anyone has any additional comments they'd like to make? Do you think we've missed anything that should be discussed?
Now to wrap-up I'd like to go over the things that have come up as important issues, to make sure that I understood you properly. [Review and confirm maior ideas.]
Wrap-up & thanks for coming ...
Appendix H. Summary of Nomal Power Profiles During Gait
Table H.1. Summary of Power Bursts During Nonnal Gait (wiit~r, 1991)
% W STRIDE
Figure HA. Powers of the Hip, Knee and Ankle for 19 Nonnal Adults
Power Generation or Absorption
Absorption Generation Absorption Generation Absorption Absorption Generation Absorption Generation
Walking at Slow (left) and Natural (right) Cadences, showing Ensemble Averages and one Standard Deviation (Winter, 1991)
Action
Eccentric
Power Burst
A1
Musde Group
Ankle Plantarflexors Concentric Eccentric Concentric Eccentric
A2 1 Ankle Plantdexors K1 I Knee Extensors K2 K3
Knee Extensors Knee Extensors
K4 H1 I32 H3
Knee Flexors Hip Extensors Hip Flexors Hip Flexors
L
Eccentric Concentric Eccentric
Concentric
Appendix I. Gait Analysis Case Study #I
This individual (S 1) demonstrated negative PC1 results (see Section 4.3- 1 for explanation of PC1
results) with ToeOK Results are presented in a case study format, and the mean profiles of healthy adults
waking at similar speeds are superimposed on aU graphs (Witnter, 1991)- A summary of normal power
profiles during gait is presented in Appendix H
1.1 Temporal and Distance Measures
Descriptive statistics for temporal and distance measures were averaged over three strides for
each side, and are reported for SI in Table 1-1, Natural walking speed in the gait laboratory was greater
for the three trials on the unafl[ied side, when wearing ToeOK Thus merences between the aEected
and UniLffected side, when wearing T m may be partially esylained by differences in walking speed
There was little difference in stance, swing or double support time when wearing each of the two orthosesc
In both cases a shorter duration of swing and longer duration of stance was observed on the &med
side.
Table 1.1 Mean of the Temporal and Distance Measures of Gait for S1
Variables
Walking Speed (ds) Cadence (stepsfminute) Stride Length (m) Initial Double Support (%) Final Double Support (%) Total Double Support (%)
* Symmetry Ratio = time taken for the swing phase of afFiected Ie&/dkcted leg
Affccted Side Original I ToeOff
Stance (9% of gait cycle) Swing (% of gait cycle) Symmetry Ratio*
Unafkted Side OriginPL I TOeOff
AFO 0.80 90.4 1.07 12.7 16.3 29.0 58.7 41.3 1.38
AFO 0.82 94.9 1-04 13.7 18-0 3 1-7 60,3 39-3 1.35
AFO 0.76 87.8 1.04 12-7 11-7 24.3
AFO 0-96 98.7 1-17 12.33 8.3 20.7 I
68-7 3 1.3 1-40
70.3 29-7 1-66
1.2 Kinematic Variables
Relative angles of the ankle, knee and hip joint on the affected and d e c t e d sides were
caiculated for three trials on each side, and averaged maximum values are reported for S I in Table 12.
Maximum dorsi€le.don of the afkted side during stance was notably less with the ToeOEAFO-
Mauimum plantadlesion at push4f was greater with TocOff on the unaflicted side. hdiucimum hip
flexion of the unaffected side was greater with Toe06 while other values were comparabie.
Table 1.2 Relative Angles of the Ankle, Knee and Hip Joint (degrees) for S1
Joint Angle Profiles
Figures 1.1 and 1.2 show the relative angles of the ankle, knee and hip joint of S 1 for three trials
on each side. when wearing the original AFO and ToeOff AFO respectively. These figures also include
angle profiles of healthy adults walking at a similar speed (Winter, 199 1).
On the affected side, S1 showed slightly more hip flexion than normal during swing with both
orthoses, as well as slightly increased hip extension during stance with the original AFO- However the
hip profiles of the affected side, paruparucularly when wearing Toeoff; are very similar to those of healthy
adults walking at a similar speed. On the unaffected side, S1 demonstrated greater hip flexion than
nonnal with both ortiloses This difference was more pronounced with ToeOff, particularly during the
swing phase.
Compared to normal values and to the lrnRffectecL leg, reduced knee flexion during the swing
phase was seen on the affected side; this reduction was nuked and of similar degree with both orthoses.
Variables
Dorsiflesion Mas over Stance Plantadlesion Mas over Stance Knee Flexion Max over Swing Hip Flexion Mas over Stride Hip E\?ension Max over Stride Hip Range over Stride
Affixted Side 0 rigind
AFO 16-79
-25-42 35.46 29.04 -15.32 41-36
Unaffected Side T- AFO 5.64
-27.54 35.15 27-37 -12.59 39-96
Origind AFO 19-02
TocOff AFO 17-00
-10-45 72.62 33 -62 -13-06 46.68
-17.98 72-04 40.56 -14-36 54-92
1 I Unaffected Side I I Affected Side I
ANKLE ANKLE
0 10 20 30 40 50 60 70 $3 90100 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0 PERCENT OF GAT CYCLE (%) PERCENT OF GAIT CYCLE (%I
Figure 1.1 Joint Angle Profiles (degrees) of the Hip, Knee, and Ankle Joint of S1 for three strides when walking with original AFO (thin lines) cornparad to healthy adults walking at a similar speed (thick line)
Unaffected Side Affected Side
KNEE KNEE
0 10 20 30 40 5 0 6 0 7 0 8 0 90100 0 10 20 30 40 50 60 70 80 9U 100
t ANKLE ANKLE
I
0 10 20 30 40 50 60 70 80 901CIJ 0 10 20 30 40 50 60 m 901~i0 PERCENT OF GAIT CYCLE (%I PERCENT OF GAIT CYCLE (?6) I
Figure 1.2 Joint Angle Profiles (degrees) of the Hip, Knee, and Ankle Joint of S1 for three strides when walking with ToeOff AFO (thin lines) compared to healthy adults walking at a similar speed (thick line)
Furthermore, the timing of peak knee flexion on the Hectcd side occuned earlier with both
orthoses. Less knee flesion of the affected side dun'ng early stance phase was also obsewed; this
difEerence w a s much more pronounced with T- For the unaffected side, peak knee fla*on was
greater and occurred later than normal with both orthoses
With the original AFO, peak plantarflm-on of the affected side at push-off was similar to normal
values for two trials, and greater than normal for the third- With the ToeOff AFO, peak pIantarflexion of
the affected side was greater than normal on all three triaIs- Dorsiflexion of the affected side during
stance was above normal w i t h the orighai AFO, and bdow normal with Ta For the u n a f f i i sik
peak pIantarflesion at push-off occurred slightfy later in the gait cycle with both orthoses, and was below
normal with the original AFO- Peak plantarflexion of the unaffied side at pash-off was greater with
T o e m with hvo trials approaching normal values, With both orchoses, dorsiflexion of the u n a f f i
side during late stance was greater than normal, and with ToeOff; increased plantarflexion during early
stance was observed
1.3 Moments
Joint moments (Nm/kg) of the ankle, knee, and hip joints were calculated for time on
each side with each AFO, and averaged rna.xhum and minimum d u e s at seiected phases of the gait
cycle are reported in TabIe 1-3- The peak ankle plantarflexion moment during stance phase was higher
with the original AFO on the affected side, but higher with ToeOffon the unaf5ected side. The peak knee
flexion moment during stance piuse tvas notably higher witti ToeOff, on the afEected side,
The peak hip estension moments over the entire stride and during the swing phase were higher with
ToeOff on the unaffected side-
Joint Moment Profiles
Figures 1-3 and 1-4 show the moments of the ankie, knee and hip joints of S1 for three trials on
each side, when wearing the original AFO and T o e AFO rtspectively- These figures also iaciude joint
moment profiles of healthy adults walldng at a similar speed (Winter, 199 1).
The hip moment pofiks of the affected side for S1 were similar to the hip profile of healthy
adults, but showed an increase in the hip fie-don moment during late stance, particularIy with the original
Table 1.3 Peak Moments (Nmlkg) of the Ankle, Knee and Hip Joints for S1
AFO- For the unaffected side, Sl demonstrated an increase in both the hip e~qension moment during
early stance and the Iup flesion moment during late stance, with both orthoses. This effect was somewhat
greater with Toeoff.
On boll1 the affected and unatrected sides. the knee extension moment during early stance was
lower than normal with both ortlroses. On the affected side, this merence was much more pronounced
with Toeoff- An i n d knee extension moment on both sides during late stance was also absented
On the affected side, this difference was more noticeable with the original AFO. S 1 also demonstrated an
increased knee flcsion moment on the affected side, during stance phase and with the ToeOfforthosis
oniy .
Variables
Ankle m x (PF) over Stance Ankle Min OF) over Stance AnkIe Range over Stance
U n a f f i i Side Original AFO 1.28 -0.08 1.36
Affected Side ToeOZf AFO 1.40
-0.08 1.48 0.59 4.56 1-15 1.26
-0.75 I
2-0 1 0.38
OriginaI AFO 1-35 4-02 1-37
Knee m x (EM) over Stance I 027
ToeOfF AFO 1-17 4.03 1.20 0.21 0.62
4.46 1-08 0-9 1 4-73 1.64 0.16
Knee Min (Flex) over Stance Knee Range aver Stance Hip Mas (Est) over Stride Hip Min (Fles) over Stride Hip Range over Stride Hip Max (Est) over Swing
4.33 0.60 0.52 -0.7 1 1.23 0.24
4.61 0.82 0.53 -0.72 1-25 0.24
1 Unaffected Side I I Affected Side I
1.5 : HIP
KNEE
j5 5
ANKLE 2.5
KNEE
5
ANKLE
1
0 10 20 30 40 50 60 70 83 90lM PERCENT OF GAIT CYCLE (%I
L
0 10 20 XI 40 50 60 70 80 913100 PERCENT OF GAIT CYCLE (%)
Figure 1.3 Joint Moment Profiles (Nmlkg) of the Hip, Knee, and Ankle Joint of S l for three strides when walking with original AFO (thin lines) compared to healthy adults walking at a similar speed (thick line)
I Unaffected Side 1 I Affected Side
HIP L
KNEE 1 -5 -t i
ANKLE 2.5 1 I
0 1 0 2 0 3 0 4 0 5 0 ~ 7 0 8 0 9 0 1 0 0 PERCENT OF GAT CYCLE (%)
1.5 ; HIP
f
KNEE
5
ANKLE 2.5 1 I
0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0 PERCENT OF GAIT CYCLE (%)
Figure 1.4 Joint Moment Profiles (Nmlkg) of the Hip, Knee, and Ankle Joint of S1 for three strides when walking with ToeOff AFO (thin lines) compared to heafthy adults walking at a similar speed (thick line)
The peak ankle pranta+nesion moment at @&was Iowcr than n o d on both sicks and with
both orthoses- On the af]Tected side, this moment was slightly higher with the ori- AFO; on the
unaffiected side, it was slightly higher with ToeOfE With both orthoses, timing of the peak a d e
plantarflesion moment occumd later than n o d on the Unasrected side.
1.4 Powers
Powers (W/kg) across the ankle, knee and hip joints were caIculated for three strides on each side
with each AFO, and maximum and minimum values at selected phases of the gait cycle are reported in
Table L4. Power absorption (AI, H2) and generation (A2, K2, HI, H3) at all three joints was greater on
the affected side with the original AFO, but greater on the unaffected side with ToeOK
Table 1.4 Peak Powers (Wlkg) of the Ankle, Knee and Hip Joints for S1
Variables
Joint Power Profiles
Figures 1.5 and 1-6 show the power profiles at the ankle, knee and hip joints of S1 for three trials
on each side, when wearing the original AFO and ToeOff AFO respectively- These figures also include
joint power p r d e s of I~ealthy adults walking at a similar speed (Winter, 1991)-
POWER (Wfkg) P g p g b g
0 10 20 30 4 0 5 0 6 0 70&O90100 0 1 0 2 0 ~ 4 0 5 0 6 0 7 0 8 0 # 3 1 0 0
ANKLE ANKLE
E 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 A 80 90100 PERCENT OF GAT CYCLE (%] PERCENT OF GAIT CYCLE (96)
Figure 1.6 Joint Power Profiles (Wlkg) of the Hip, Knee, and Ankle Joint of S1 for three trials when walking with ToeOff AFO (thin lines) compared to healthy adults walking at a similar speed (thick line)
Compared to normal values, hip powerpro~cs ofthe afktcd side showed iocrmscd power
generation at H1 and H3, particularly with the original AFO, An increase in power absorption at EI2 was
also present with the originai AFO. For the unaftiected side, higher power generation at H1 and H3 was
also seen, but with the ToeOf€ortbosisrtbosis Incnascd power absorption at H2 occumd with both
orthoses, but especially with T e -
Power profiles of the affected knee were similar to normal values with both orthoses, except for a
shift in timing of power absorption at K3 towards earlier in the cycle with both orthoses, and an increase
in this power burst with the original orthosis especiatly- Power generation of the f l i e d side at K2 was
greater with the originaI AFO. For the unafkted side, an increase in power absorption at K3 ocamed
with both orhoses but with T d f f in particular-
AnkIe power profiles showed near n o d power generation (A2) with the original AFO, but
values below nonnal with ToeOfE For the unaffected side, power generation at the ankle was above
normal with both orthoses, but considerably greater than normal with ToeOE Power absorption at the
unaffected ankle (Al) was slightly greater than normal on both sides and with both orthoses, although the
increase was most pronounced with Tm
1.5 Work
Work (JAcg) across the ankle* knee7 and hip joints were acquired for three strides on each side
with each AFO, and mean values for selected events of the gait cycle are reported in Table 1-5- -tive
work at the ankte was greater with the original AFO on the affied side but greater with Teen the
unaffected side, Positive work at the knee was greater with ToeOff on the afliected side but greater with
the original AFO on the dkcted side. Positive work at the hip was greater with the original AFO on
both sides,
Table 1.5 Work (Jlkg) at the Ankle, Knee, and Hip Joints for S1
Variables
Ankle (A2) Positive , Knee (Kl) Negative Knee (K2) Positive Knee (K3) Negative Knee (KI) Negative Hip (HI) Positive Hip (H2) Negative Hip (H3) Positive
M i Sick Una- Side Original AFO 0.24
0.084 0.00 10 0.048
Original AFO 0-15
0,033 0,020 0.39
TocOff AFO 0.13
0.0050 0,021 0,036
TocoflT AFO 0.26
0.0023 0.0090 0.036 0.0031 0.0060
0.24 0.0 10 0.13
0-003 L 0-14 0.021 0.025 0.084
0.16 0.18 0.22
0-13 0.022 0-1 1
Appendix J. Gait Analysis Case Study #2
This individual (S16) demonstrated positive PC1 results (see &on 4.3-1 for eupfanation ofPC1
results) with ToeO& Results an presented in a case study fomrat, and the mwn profiles ofhealthy adults
walking at similar speeds are supimposed on all graphs (Winter, 1991)- A summaty of n o d power
profiles during gait is presented in Appendix H-
J.1 Temporal and Distance Measures
The descriptive statistics for tempotal and distance measur~s were averaged over three trials for
each side, and are repaned for S16 in Table 1-I, Average walking speed was greater for the three strides
taken on the affected side when wearing the original AFO. Comparison of the profiles of the affected
side, when wearing the original AFO may therefore differ fiom other pmfi.les due to differences in speed
alone. There was little Merence in stance, swing or double support time when wearing each of the two
orthoses, as well as little difference in stance and swing time of the af5ted and unafllected sides-
Table J.l Mean of the Temporal and Distance Measures of Gait for S16
* Symmetry Ratio = time taken for the swing phase of affected leg/unaffected leg
Unaffected Side Original I ToeOff Variables
Walking Speed (m/s) Cadence (stepshninute) Stride Length (m) Initial Double Support (%) Final DoubIe Support (%) Total Double Support (%) Stance (% of gait cycle) Swing (% of gait cycle) Symmetxy Ratio*
Affiited Side 0rigin;nd I ~ o e ~ f f
AFO 1.54
107.5 1-71 9-3 10-7 20.0 58-7 41.3 1-07
AFO 1.42
107.5 1.58 9-7 13.3 23-0 60-7 39.3 1 .04
AFO M O 1-38 1.39 a
102.4 1 108.0 1.62 10 11 21 61 39 1-03
1.54 11.3 13
24.3 62-7 37.3 1.02
J.2 Kinematic Variables
Relative angles of the ankle, knee and hip joint on the af]Tected and unafftcted sides were
averaged over three trials on each side, and mavimum values are hported for S16 in TabIe 1.2- MBximum
plantarflexion at pushqff was greater on the afEected side with T m but slightly greater on the
unaffected side with the original AFO. Mhximum hip extension and hip range were slightly greater with
ToeOff on both sides.
Table J.2 Relative Angles of the Ankle, Knee and Hip Joint ( O ) for SW
Affected Side Original I T m
Joint Angle Profiles
U n a f f " Side 0righ.I I ToeO(f
Dorsiflexion Max over Stance PIantarfle.uon Max over Stance Knee Flexion Ma.-.- over Swing Hip Fksion Max over Svide
Figures J-1 and J.2 show the relative angles of the ankle, knee and hip joint of S 16 for three trials
on each side, when wearing the original AFO and ToeOff AFO respectively, These figures also include
angle profiles of healthy adults walking at a similar speed (Winter, 1991).
Orr the affected side, S 16 showed more hip Qesion than normal thosghout the gait cycle, This
effect was more pronounced with the original AFO, where the hip never extended past neutral- With the
ToeOff orthosis, relative angles of the aEected hip were closer to normal values, particularly during the
latter half of the gait cycle- Joint angle profiles of the unaffected side more closely approximated normal
values with both orthoses, although more hip flexion than normal was again seen during stance phase-
On both the afEected and unafliected side, maximum hip extension was closer to normal with the T o e
ortllosis.
AFO 18.48 4.3 1 70.67 54-74
AFO 17.56 0.027 64.82
Hip Estension Mas over Stride Hip Range over Stride
0.72 34.02
-8.94 39-53
AM) 11.27 -8.64 65. LO
-5.075 38.73
AFO 14-94 -6.36 68-29
4- 14 3 5-88
30-59 33 -65 29.74
Affected side1 1 Unaffected Side I
KNEE 90.0
KNEE
I
ANKLE ANKLE
0 10 20 30 40 50 60 70 80 90 100 0 1 0 2 0 3 0 4 0 ~ ~ 7 0 8 0 9 0 1 0 0 PERCENT OF OAlT CYCLE (%) PERCENT OF GAlT CYCLE (%)
- - - - L Figure J.l Joint Angk Profiles (degrees) of the Hip, Knee, and Ankle Joint of S16
for three strides when walking with original AFO (thin lines) compared to healthy adults walking at a similar speed (thick line)
Affected side1 I Unaffected Side I 1
ANKLE ANtUE
0 10 20 30 40 50 60 70 80 90 100 0 1 0 2 0 ~ ~ ~ 6 I l 7 0 8 0 ~ 1 ~ PERCENT OF GAIT CYCLE (%) PERCENT OF GAIT CYCLE (%)
I
Figure J.2 Joint Angle Profiles (degrees) of the Hip, Knee, and Ankle Joint of S16 for three strides when walking with Toem AFO (thin lines) compared to healthy adults walking at a similar speed (thick line)
Compared to normal values and to the Meted icg, increased knee flexion during stance and
early swing phase was seen on the affected side with the original AFO. Wnh TocOff, relative angb of
the affected knee much more closely approximated n o d valacs, although increased fIaion duting
stance was again demonstrated Notable w a s the magnitude ofextension prior to swing. For the
unaffected side, increased knee flexion during stance also occurred with both orthoses, aithough this
difference was much more pronounced with the originaI orthosisosis
With both orthoses, peak plantarflexion of the affiected side at push-off was notably lower than
normal. Peak plantarfIexion oftbe afktedside was sirnilat with both orthoses7 with the exception of one
trial with the original AFO where noticeably greater plantadexion was achieved. Throughout the gait
cycle, greater dorsiae-uon than n o d was demonstrated on the affected side with the original AFO; with
ToeOff dorsiflesion of the affected side approached n o d during stance, but was greater than normal
during swing, Joint angle profiles of the d e c t e d ankle were very close to normai with both orthoses,
although peak plantarflexion was slightly below normal in both cases, and increased dorsiflerdon during
late stance occuned with ToeOfF.
J.3 Moments
Joint moments (Nralkg) of the ankle, knee, and hip joints were averaged over three strides on
each side with each AFO, and maximum and minimum values at seIected phases of the gait cycle are
reported in Table J.3. The peak ankle plantarflexion moment during stance phase was higher with the
sriginal AFO on the affected side, but higher with Teen the d e c t e d side. Similatly, the
maximum knee exlension and minimum knee flexion moments during stance, and the maximum hip
estension and iiikirnum hip flesion moments during suide, were greater with the original AFO on the
affected side, but greater with ToeOffon the &ected side.
Joint Moment Profiles
Figures 1.3 and J-4 show the moments of the ankle, knee and hip joints of Sl6 for three trials on
each side, when wearing his original and ToeOff AFO respectively. Thcse figures also include
joint moment protiles of healthy adults walldng at a dmilar speed ( W i i * 1991).
Table 5.3 Peak Moments (Nmlkg) of the Ankle, Knee and Hip Joints for SIB
On the affected side. the hip moment profiles of S16 showed an increased extension moment
b
M ' e d Side Un&fixted Side Variables Original T e Origind Toeoff
AFO AFO AFO AFO Ankle Mas (PF) over Stance 1-40 1 1, I2 1-85 2-21
during early stance, and a slightly increased flexion moment during late stance. Both moments were
Knee Max (Ext) over Stance Knee Min (Flex) over Stance Knee Range over Stance Hip Ma.. (Ex?) over Stride Hip Min (Flex) over Stride Hip Range over Stride Hip Max (Ex%) over Swing
notably more pronounced with the original AFO. On the d i e d side, S l6 also demonstrated an
increased Iup exqension moment during early stance, and a slightly increased hip flexion moment during
1-42 -0.84 226 2.62 4-78 3-41 0.32
Iate stance. Moments on the unaffected side were comparable with both orthoses, with the exception of
one trial with ToeOff in which the hip flexion moment was notably greater,
1-10 -0.65 1.75 1-70
-0.72 2-41 0-41
On both the affected and unaffected sides and with both orthoses, the knee estension moments
during early and late stance were notably higher than normal, On the affected side, peak knee extension
moments were higher with the original AFO; on the d e c t e d side, peak knee extension moments were
comparable with both orthoses, with the exception of one trial with T o m i n which both moments were
1.34 4.29 1.62 1.39 4-94 2.32 0.27
particularly Iugh-
The peak ankle plantarflesion moment at push-off was lower than normal on the a81ected side
with both orthoses, but was much closer to n o d with the original AFO. On the unaEected side, the
peak plantarflesion moment at push-off wa higher than n o d with both orthoses, and highest with the
1.62 -0.56 2-18 1-81 -1.16 2-% 0-49
ToeOff AFO- During early stance, an increased dorsiatxion moment on the unaffected side was also seen
with both orthoses.
Affected side/ I I Unaffected Side I I
4.0 HIP
i t
KNEE 2.0 7
A 1
ANKLE 2.5 1
0 10 20 30 10 50 60 70 00 90 100 PERCENT OF OUT CYCLE (96)
HIP 4-0 i I
KNEE 2.0 1
ANKLE 2.5 j
0 1 0 2 0 3 a 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0 PERCENT OF GAIT CYCLE ('36)
Figure J.3 Joint Moment Profiles (Nmkg) of the Hip, Knee, and Ankk Joint of Sf6 for three strides when walking with original AFO (thin lines) compand to healthy adults walking at a similar speed (thick line)
-160-
1 KNEE
Affected side/
ANKLE
I
I Unaffected Side I I
i 0 10 20 30 40 50 60 70 80 90 100 PERCENT OF GAIT CYCLE (%)
!
HIP
KNEE 2.0 1
ANKLE
-1.0 J I 0 1 0 2 0 30 40 50 6 0 7 0 8 0 9 0 1 0 0
PERCENT OF GAIT CYCLE (%)
Figure J.4 Joint Moment Profiles (Nmlkg) of the Hip, Knee, and Ankle Joint of 516 for three strides when walking with ToeOff AFO (thin lines) compared to healthy adults walking at a similar speed (thick line)
J.4 Powers
Powers ( W k g ) across the W e , knee and hip joints were averaged over three on each
side with each AFO, and maulmum and minimum values at selected phases of the gait cycle are reported
in Table J.4, Power absorption at A1 and H2, and power generation at K2 and H3 were greater with
ToeOffon both sides, Power generation at A2 and H1 was p t e r on the affected side with the original
AFO, but greater on the d i e d side with T-
Table J.4 Peak Powers (Wlkg) of the Ankle, Knee and Hip Joints for S16
I AFO 1 AFO I AFO I AFO Variables
Knee Mas over Stride I 1-6 1 I 1-32 1 0.59 I 1-32
Mf&cted Side Original I TaOrr
Ankle Max (A2): generation Ankle Min (Al) over Suide: absorption Ankle Range over Stride
Unafkted Side Original I ToeOa
Knee Range over Stride I 5.14 1 4.77 1 3-34 I 4-77
1-09 4-65 1-74
Knee Mas (K2): generation Knee Min over Stride
0.83 -1.34 4.75
0-79 -3.53
Hip Max over Stride Hip Mas (HI) over Stance: generation Hip Min (HZ): absorption
Joint Power Profiles
Hip Max (W) at pull-ofE generation Hip Range over Stride
Figures J.5 and J.6 show the power profiles at the ankle, knee and hip joints of S16 for three
2-67 4-85 3 -53
0-94 03-45
1-18 1-18
-0.2 1
triaIs on each side, when wearing the original AFO and ToeOff AFO respectively. These figures also
3-40 -1.35 4-73
0.71 1.40
include joint power profiles of healthy adults walking at a similar speed (Winter, 1991).
0.37 -2-75
0.98 0.79 4-79
Hip power profiles of the affected side showed higher than n o d power generation at H1 with
0-94 03-45
0.91 1-77
both orthoses. One triaI with the original AFO showed an especially high peak at HI. For the d i e d
0-67 0.59 4-35
side, both higher power generation at H1 and higher power absorption at H2 were seen with both orthoses;
0.98 0-79 4-79
0-60 1-21
0.94 1-77
I Affected side1 1 I UnafFected Side 1
2.0 1 HIP
ANKLE 6.0
0 10 20 30 40 50 60 TO 80 90 100 PERCENT OF GAIT CYCLE (96)
20 5
HIP
1-5 ..------ ------ ------------- --------
KNEE 3.0 1 1
ANKLE
6-0 0
0 10 20 30 4050 60 70 80 90100 PERCENT OF GAIT CYCLE (%)
Figure J.5 Joint Power Profiles (Wlkg) of the Hip, Knee, and Ankle Joint of S16 for three strides when walking with original AFO (thin lines) compared to healthy adults walking at a similar speed (thick line)
- 163 -
I Affected side 1 I 1 UnafFected Side I
2.0 i HIP
1
KNEE 3.0 i
ANKLE
I
0 10 20 30 40 50 60 70 80 90 100 PERCENT OF GAlT CYCLE (%)
KNEE
-2.0 I 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0
PERCENT OF GAIT CYCLE (%)
Figure 5.6 Joint Power Profiles (Wlkg) of the Hip, Knee, and Ankle Joint of S16 for three strides when walking with ToeOff AFO (thin lines) compared to healthy adults walking at a similar speed (thick line)
these values were slightly higher with the ToeOffoxthosis. One ofthe trials with TocOfjEalso
demonstrated increased power generation of the unaffected hip at H3,
Power profiles ofthe af]&tedknee s h o d inarased power absorption at K1 and K3, and
slightly increased power generation at KZ, compared to normal values- On average, absorption at K1 was
greater with the original AFO, wMe absorption at K3 was greater with T- The d e c t e d knee also
sho~ved increased power absorption at Kl and K3 with both orthoses, and increased generation at K2 with
ToeOffonlyy One of the trials with T'demonsfxated mcularfy bigh absorption of the unaffected
knee at K3-
Ankle power profiles showed a decrease in power generation ofthe affkcted side at push-off (A2),
which was similar in degree with both orthoses. For the unafEened side, average power generation at the
ankle was below normal with the original orthosis, but greater than normal with T o e Power
absorption at the ankle (Al) was slightly geater than n o d on both sides and with both orthoses,
although the increase was most pronounced with ToeOE
J.5 Work
Work (Jkg) across the ankle, knee, and hip joints were acquired for three strides on each side
with each AFO, and mean values for selected events of the gait cycle are reported in Table 4-4. Positive
work at the ankle joint (A2) was very similar with the two orthoses on both sides. Positive work at the
knee and 11ip joints were identical with both orthoses on the afEected side, while positive work at the knee
joint (K2) was higher on the d e c t e d side with ToeOff, and positive work at the hip joint (H3 only) was
higher on the unaffected side with ToeOK
Table J.5 Work (Jlkg) at the Ankle, Knee, and Hip Joints for S16
Variables
Ankle (A21 Positive Knee (KL) Negative Knee (K2) Positive Knee (K3) Negative Knee (KI) Negative Hip (HI) Positive Hip (H.2) Negative Hip (H3) Positive
Affiited Side ClnolTccted Side
original AFO
0-06 0-32 0-08 0-18 0-12 0.22 0.02 0-13
Original AFO 0.25 0.27 0-03 027 0-12 0-14 0-08 0.06
TocOflC AFO 0.04 0, t6 0-08 020 0-13 022 0-02 0-13
Toeoff AFC- 0.27 0.26 0-10 0.35 I
0- 16 0-14 0.1 1 0-12
Appendix K. Reference Values for Clinical Assessment Measures
Table K.1. Normal Active Range of Motion C) of the Ankle, Knee and Hip
Table K.2. Normal Passive Range of Motion (') of the Ankle, Knee and Hip
Hip E
20 (knee E)
-
18 (prone, knee E)
17 (prone, heeE)
Source
David (1988)
WaUcer et al. (1984)
Roach& Miles (1991)
Age
Not given
60-84
40-59
Hip E - 30
(knee E)
Ankle PF
30-50
34
-
-
*O F); I5
( h e E)
AnWe DF
20-30
10
-
Miles (199 1)
Source
Hip F
120 (knee F)
111
120 (supine, knee F)
-
Knee F
120 (hip E)
133
132 (supine)
Roach& Miles (1991)
132 (supine)
120-130 (hip E)
140 (hip F,
Hip Knee Anlde Age
118 {supine, knee F)
Knee E
0
-
-
13 1 (supine)
25-74 121
(supine, kneeF)
115-125 (knee F)
125 (knee F)
-
0
F 140-150 (knee F)
Kaee Ankle
-
-
60-74
19 (prone, h e e E )
10-15 (knee E)
10 (knee E)
David (1988)
40-45 (knee E)
45
-
Daniels &
(1980) Kendall & McC'eq (1983)
Not
Not given
Not given
I
E
0
PF
30-50
DF 1 F
20-30 160
(hip E)
Table K.3. Normal Muscle Strength (kg) of the Ankle, Knee and Hip
Ankle DF
Hip F
Andrews et ck (1 996)
Andrews et ai 1 (1996)
Andrews et ar (1996)
Andrews et a1 (1996)
Andrews et al (1 996)
Backman et al. (1995)
Backman et a[- (1995)
Calahan el all 1989) r-