Biomechanics and Walking in Cerebral Palsy: Ankle Foot Orthoses - Footwear Combinations
Phase: NA
Conditions: Cerebral Palsy (CP)
Sponsor: Seattle Children's Hospital

 
 
 
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NCT03756571 
PROTOCOL 
 
Cerebral Palsy: Ankle Foot Orthoses - Footwear 
Combinations 
 
August 7, 2018 
 

 
 
 
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Study Protocol 
Version: 1.0 August 7, 2018 
Ankle Foot Orthoses – Footwear Combinations  
(AFO-FC): Biomechanics and Walking Activity in 
Cerebral Palsy 
Principal investigators:  
Kristie Bjornson, PT, PhD, PCS 
 
 
Study site: 
 
Orthocare Innovations- Biomechanics Laboratory 
 
 
 

 
 
 
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Contents 
 
List of Abbreviations ...................................................................................................................... 43 
Research Synopsis ........................................................................................................................ 54 
Background and Significance ........................................................................................................ 65 
Objectives ...................................................................................................................................... 87 
Primary Objective ...................................................................................................................... 87 
Secondary Objectives ............................................................................................................... 98 
Study Design and Methodology ..................................................................................................... 98 
Study Population.......................................................................................................................... 109 
Sample Size ............................................................................................................................ 109 
Inclusion /Exclusion Criteria .................................................................................................. 1110 
Study Duration, Timeline, and Procedures ................................................................................ 1210 
Statistical Analysis Plan ............................................................................................................. 1211 
Informed Consent Process ........................................................................................................ 1413 
Privacy and Confidentiality ........................................................................................................ 1413 
Risk/Benefit ................................................................................................................................ 1514 
Risk to participants ................................................................................................................ 1514 
Benefits to participants .......................................................................................................... 1514 
Data Safety Monitoring .............................................................................................................. 1514 
Conflict of Interest ...................................................................................................................... 1514 
Publication and Presentation ..................................................................................................... 1514 
References .................................................................................................................................... 15 

 
 
 
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List of Abbreviations 
AFO- 
 
Ankle foot orthoses   
AFO-FC 
Ankle foot orthoses- footwear combinations 
CP 
 
Cerebral Palsy 
ROM 
 
Range of motion 
GPS 
 
Global Position System 
ASKp  
Activities Scale for Kids – Performance 
LifeH 
 
Assessment of Life Habits 
OPUS  
Orthotics and Prosthetics Users Survey 
GMFCS 
Gross Motor Function Classification System 
MACS  
Manual Ability Classification System 
SW 
 
StepWatch accelerometer 
 

 
 
 
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Research Synopsis 
Study Title: Ankle Foot Orthoses – Footwear Combinations: Biomechanics and Walking Activity in 
Cerebral Palsy 
Study Population: Children ages 4 – 14 years, inclusive, with ambulatory unilateral or bilateral 
cerebral palsy (CP).   
Study Design: A prospective pre/post intervention study with 10 ambulatory children with CP will 
compare their current AFO to the AFO-FC. Participants will be recruited from the Rehabilitation 
clinic and Physical Therapy patient caseloads of the investigators. Maximal knee extension in 
stance as well as gait speed (aim 1) will be captured by gait analysis at the Orthocare Innovations 
biomechanics laboratory in Mountlake Terrace. Community walking activity will be captured with 
the ankle-worn StepWatch accelerometer (aim 2). Mobility based participation in day to day life 
will be documented by parental report of the Assessment of Life Habits for Children (Life-H). 
Physical activity will be sampled with the Activity Scale for Kids – Performance (ASKp) and 
satisfaction with the respective devices will be examined with parental report of the Orthotic and 
Prosthetic Users’ Survey (OPUS).  
   Two outpatient study visits will be carried out before (baseline) and after (follow-up) the 
standard of care clinical visits to cast/fabricate and fit the participants’ new AFO-FC devices. At 
the baseline study visit, informed consent/assent, three dimensional gait analysis, parental report 
of mobility-based community participation, physical activity and satisfaction with device will be 
carried out while wearing their current orthoses. At the end of that visit, the participant will go 
home wearing the StepWatch accelerometer and GPS monitors for 2 weeks. The accelerometer 
will be returned to study staff by postage paid envelope. The child then has the appropriate 
clinical visits to cast, fabricate, fit and tune their new AFO-FC with a home walking program as 
appropriate. Consistency of clinical AFO-FC prescription will be addressed by the use of the 
published algorithm,1 (Appendix) currently utilized clinically by the investigators here at Seattle 
Children’s Hospital (SCH). All the AFO (plastic brace) portions of the AFO-FC devices will be 
casted at SCH and  fabricated at Cascade DAFO (Dynamic Ankle Foot Orthoses), Inc.. The 
family of the participant will supply the footwear (shoes). The footwear portion of the AFO-FC will 
be modified, fitted and tuned along with the AFO portion by the SCH orthotists and Dr Bjornson. 
Three months after the AFO-FC is tuned and finalized, they will return for the second study visit 
(follow-up) where all outcomes are collected again. 
   These results will provide the preliminary data essential for development and federal funding of 
a randomized clinical trial comparing current standard of practice “traditional’ AFO to the AFO-FC 
approach. Study participation takes 12-16 weeks within clinical orthotic management. 
Primary Objective: Examine the effect of AFO-FC on the primary outcomes of maximal knee 
extension during stance and gait speed as compared to current AFO prescription.  
Secondary Objectives: Examine the effect of AFO-FC on daily walking activity, intensity and 
mobility-based participation and satisfaction as compared to current AFO prescription. 
Sample Size: 10 children.  
Study Duration: 12 months ending Sept 30, 2015.  
 

 
 
 
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85% Point load rocker
 
Figure 1 AFO-FC. 
Background and Significance 
Cerebral palsy (CP) is the most common and costly neuromuscular 
condition among children in the US 2, 3, with a prevalence of 3.3-
3.8/1000 4 The clinical definition of CP is a group of disorders of 
movement and postural development which result in physical 
activity limitations. 5  A novel and comprehensive strategy has been 
articulated in the AFO-FC approach11, but neither the previous 
strategy (AFO type)12 nor the new strategy (AFO-FC)11 has strong 
published evidence of efficacy.(Fig 1) 
   As typically developing children walk, the lower extremity 
segments (femur, tibia and foot) align such that the knee extended 
(straight) during midstance. This allows support of body weight 
transfer during single limb support and swing through of the 
opposite leg while walking.(See Figure 2) During terminal stance 
when the heel is leaving the ground, the segments of the leg 
demonstrate a straight knee allowing an adequate step length and 
weight transfer as the opposite foot contacts the 
surface.13  
   In contrast, ambulatory children with CP 
present with crouch gait characterized by 
misalignment of the segments of the lower 
extremity 
(femur, 
tibia 
and 
foot). 
This 
misalignment of lower leg segments does not 
adequately support the transfer of weight with a 
resulting inefficient walking pattern.14 (Figures 3-
5) During midstance when the foot should be flat 
on the surface, youth with CP present with either 
excessive or insufficient lower limb inclination 
(tibia) from vertical to support weight on one leg. 
For example crouch gait (Figure 3 & 4) is defined 
as excessive knee flexion in single limb stance. 
Excessive knee flexion during stance requires 
additional effort to walk,15 causing fatigue and 
reducing walking behavior in children with CP. It 
can be observed visually, but only computerized 
gait analysis has sufficient accuracy to inform 
clinical decisions. This heterogeneity of walking 
patterns in CP requires an individualized approach 
to orthotic prescription as well as motor training to 
optimize walking skills.13  
 
Fig 3.  Abnormal leg segment 
alignment in CP  
Fig. 2. TYPICALLY DEVELOPING GAIT:  
MIDSTANCE                      TERMINAL STANCE 
 

 
 
 
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   The current regional (Pacific Northwest) standard of 
care for orthotic prescription in ambulatory CP is 
usually an AFO that allows ankle movement (See 
Figure 4). This approach does not provide adequate 
alignment of the segments of the leg (knee is flexed) 
during midstance and terminal stance), which is due to 
insufficient control and weakness of the muscles about 
the ankle joint. A crouch gait walking pattern creates 
excessive demand on the knee extensors, results in 
shorter strides and an inefficient walking pattern. The 
habitual use of a crouch gait pattern significantly 
increases the energy cost of walking. 16 In fact, a 
crouch gait pattern is associated with the need for 
future orthopedic surgery 15 and an overall decrease in 
physical activity into adulthood.17 In contrast, the AFO-
FC approach with individualized segment alignment 
and shoe modifications limits ankle movement and 
appears to enhance knee extension during mid and 
terminal stance. (See Figure 5) 
   As compared to typically developing children, youth 
with CP take significantly fewer steps per day and 
spend less time walking and engaging in activities of 
high intensity.18 van den Berg-Emons et al. reported 
that school children with spastic diplegic CP were less 
physically active than a healthy control group and that 
a typical child with CP would need to exercise 2.5 
hr/day to reach the activity level of peers.19 Children 
with CP have also been described as having one of 
the 
most 
sedentary 
lifestyles 
among 
pediatric 
disabilities.20. In a study of school-based activity 
performance and participation in Israel, youth with CP 
had significantly lower physical activity performance as 
measured by the School Function Assessment (SFA). 
The youth with CP participated significantly less often 
than their typically developing peers in daily school 
activities (i.e., playground games and moving to other 
areas of the school).21 Walking mobility has also been 
shown to be predictive of restrictive participation in 
mobility, education, and social relations for children 
with CP.22 
   It is important to consider the implications of walking 
activity 
across 
the 
life 
span. 
In 
a 
California 
Developmental Disabilities Database study, Strauss, 
and colleagues (2004) reported the longitudinal 
functional skills of adults with CP at the ages of 20, 40 
and 60 years. A marked decline in walking ability 
especially 
in 
late 
adulthood 
(age 
60), 
was 
documented.23 Self-reported functional walking in the 
community setting in late adulthood was associated 
with a longer life expectancy. CP leads to serious 
health problems that persist into adulthood2, 24,, and 
interventions to improve mobility are common although 
Fig 5. CEREBRAL PALSY-CROUCH GAIT 
AFO-FC - NO ANKLE MOVEMENT 
MIDSTANCE                TERMINAL STANCE 
 
Fig. 4. CEREBRAL PALSY-CROUCH GAIT 
AFO ALLOWING ANKLE MOVEMENT: 
MIDSTANCE     
       TERMINAL STANCE 
 

 
 
 
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only partially effective in altering the progression of the musculoskeletal consequences of the 
condition. 
   We have documented improvement in community walking activity with the StepWatch 
accelerometer in a clinical cohort of 8 children with bilateral CP comparing their current AFO with 
the AFO-FC approach.25 The children represented the following gait patterns: 3 equinus, 4 crouch 
and 1 jump gait (See Figure 6). Current AFO prescriptions all allowed full or partial ankle 
movement except for one child with a solid ankle without individualized leg segment alignment or 
shoe modifications. Average strides per day increased for all participants wearing the AFO-FC 
with an average group increase of 2,611 strides/day and a range increase from 387 to 3020. A 
minimal clinical important difference (MCID) in daily walking activity of 2,478 stride/day has been 
calculated from 37 children with CP for the average difference in strides/day walking with an 
assistive device to without.26 Thus, 
our clinical experience with the 
AFO-FC 
approach 
suggests 
positive influence on community 
walking activity.  
Summary 
The proposed protocol will help to 
substantiate our clinical experience 
with this novel approach to orthotic 
management 
in 
ambulatory 
children with CP. Currently there is 
no standardized approach for the 
orthotic 
management 
of 
this 
heterogenous 
population. 
Knowledge generated will lay the 
foundation for examining the proposed biomechanical mechanisms as well as translation to 
improved walking in day-to-day life. This work will document the effect of the AFO-FC approach 
on maximal knee extension in stance and walking speed (Aim 1).  We hypothesize that improved 
knee extension in stance will produce increased walking activity in the community and parental 
report of mobility-based participation, physical activity and satisfaction with the devices. (Aim 2) 
 
Objectives 
Primary Objective   
- 
Aim 1: Examine the effect of AFO-FC on the primary outcomes of maximal knee 
extension during stance and gait speed as compared to current AFO prescription. 
We hypothesize that 1) the ability to generate adequate knee extension in stance is 
impaired in their current AFO and contributes to limitations in gait speed and subsequent 
daily walking levels and intensity, and 2) the individualized leg segment alignment of the 
AFO-FC will produce positive improvements in knee extension during stance. Increased 
knee extension during stance will enhance the stability of stance phase, facilitate longer 
strides lengths and increased gait speed.  
- 
Knee extension during stance and gait speed will be measured by computerized three 
dimensional gait analyses. 
- 
Walking performance will be measured with the StepWatch accelerometer in each 
participant’s daily environment (39). 
 
Fig .6 Average strides/day current AFO versus AFO-FC 
Shank to vertical angle

 
 
 
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Secondary Objectives   
- 
Aim 2: Examine the effect of AFO-FC on daily walking activity, intensity and 
mobility-based participation and satisfaction as compared to current AFO 
prescription. We hypothesize that AFO-FC through improved knee extension during 
stance will result in faster walking speed facilitating a positive effect on community 
walking activity levels, intensity, mobility based day to day participation and satisfaction 
with device. Walking activity will be captured by the StepWatch accelerometer with 
participation and satisfaction assessed using parental report questionnaires  
- 
Mobility based participation in day to day life will be documented by parental report of the 
Assessment of Life Habits for Children (Life-H).  
- 
Physical activity will be sampled with the Activity Scale for Kids – Performance (ASKp) 
- 
Satisfaction with the respective devices will be examined with parental report of the 
Orthotic and Prosthetic Users’ Survey (OPUS). 
 
Study Design and Methodology 
We will conduct a prospective pre/post intervention study with 10 ambulatory children with 
unilateral (hemiplegia) or bilateral (diplegia) CP between the ages of 4 to 14 years. Participants 
will be recruited from the Rehabilitation clinic and Physical Therapy patient caseloads of the 
investigators. Two outpatient study visits will be carried out before (baseline) and after (follow-up) 
the standard of care clinical visits to cast/fabricate and fit the participants’ new AFO-FC devices. 
Outcomes –Maximal knee extension in stance as well as gait speed (aim 1) will be captured 
by 3 dimensional gait analysis at the Orthocare Innovations biomechanics laboratory in 
Mountlake Terrace. Community walking activity will be captured with the ankle-worn StepWatch 
accelerometer (aim2). Mobility based participation in day to day life will be documented by 
parental report of the Assessment of Life Habits for Children (Life-H). Physical activity will be 
sampled with the Activity Scale for Kids – Performance (ASKp) and satisfaction with the 
respective devices will be examined with parental report of the Orthotic and Prosthetic Users’ 
Survey (OPUS). 
 
Gait Analyses: Two gait analyses at self-selected walking speed will be conducted. At the 
baseline visit, gait will be 
recorded 
barefoot 
(to 
characterize 
gait 
pattern, 
Figure 3) and with current 
orthoses and shoes. Three 
months later, at Visit 2, gait 
analysis barefoot and with 
the 
AFO-FCs 
will 
be 
performed. 
To 
ensure 
consistency of motion data, 
markers will be attached by 
the same experienced lab 
personnel using the Plug In 
Gait model. Post-processing 
of all gait lab data will carried 
out 
by 
one 
individual. 
Markers will be placed on the 
0%
20%
40%
60%
80%
100%
Terminal 
Stance
-15
0
15
30
45
60
Cerebral Palsy
Crouch Gait
Typically 
Developing
Primary Outcome Measure:
Maximum Knee Extension
AFO-FC tuning goal: 
shift curve down
Percent Gait Cycle
Stance Phase
Swing Phase
Sagittal Knee Angle
Flex 
(Bent)
Ext 
(Straight)
Figure 7. Knee extension output from gait analysis 

 
 
 
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child to accurately collect the three dimensional joint motions and forces using an 8-camera Vicon 
MX system with two integrated AMTI force platforms. Primary outcome variable: Maximal knee 
extension in terminal stance will be extracted from the data to quantify crouch gait in the current 
AFO vs. the AFO-FC. (Figure 7)  Additional joint motion and force data will also be reviewed to 
understand the interactions of possible gait adaptations displayed by the participants. 
 
StepWatch (SW): Accelerometers will be used to determine how much participants actually walk 
on a daily basis. The StepWatch (SW) is a small, lightweight device that looks like a pager and is 
strapped around the ankle. The SW measures the number of steps taken during a day at low, 
medium and high intensities. Participants will take this device home and wear it during walking 
hours for two weeks. Participants will return the SW by mail using a stamped mailing envelope 
supplied to them. The walking activity in average number of steps per day as well as number of 
steps in each intensity level per day will be obtained. These variables will be averaged for a total 
week of activity, weekday activity, and weekend activity to be used in the analysis. 
 
Activity Scale for Kids-Performance Version (ASKp): The ASKp, a child self-report questionnaire 
measures what the child “did do” during the previous week. It will be used to measure activity 
performance in this study. Validity, reliability and sensitivity of this measure have been 
established for the population in this study.27 There are 7 sub-domains represented within the 
ASKp including: personal care (3 items), dressing (4 items), other skills (4 items), locomotion (7 
items), play (2 items), standing skills (5 items), and transfers (5 items). Child report will be used. 
The 30 items aggregate will be used to obtain one overall summary score for analysis. 
 
Assessment of Life Habits (Life-H): The LIFE-H questionnaire will be used to sample mobility-
based l life habits carried out in the participant’s natural environment (home, school, 
neighborhood). For the purpose of this study the LIFE-H short form for children 5-13 years will be 
used, which, per developer is appropriate for 4 year-olds as well. The domains of housing, 
mobility and recreation will be the focus of this study. The LIFE-H produces a continuous score 
ranging from 0 to 9, which are developed by combining the results of the sub-score related to the 
degree of difficulty and type of assistance. The instrument also has a separate satisfaction scale 
that provides the individual’s assessment regarding accomplishment of life habits (5-point Likert 
scale). Parental report will be used in this study. The mean of each category (mean of items) for 
accomplishment and satisfaction will be used in the analysis. 
 
 
Orthotic and Prosthetic Users’ Survey (OPUS): The OPUS is a self-report instrument that was 
developed to assess patient outcome in the areas of functional status, quality of life, and 
satisfaction with devices and services. 28 For the purpose of this study only the satisfaction with 
device scale will be used. It consists of 11 questions addressing orthotic comfort, fit, and 
wearability and uses one rating scale with four “extent of agreement” response categories. Child 
report will be used as feasible and if not then parental report will be collected. Data will be 
converted to ordinal or nominal data categories for analysis. 
Study Population 
Sample Size   
Our long-range plans are to carry out a multi-site randomized trial comparing AFO-FC with AFO. 
Feedback from the NIH regarding these plans has indicated that we should first collect 
preliminary data on effect sizes and variability, in order to inform sample size and power 
calculations for such a study. Our TRIPP proposal is designed to achieve this goal within the time 
and budget limitations. Therefore, the proposed study is neither designed nor powered for 
inference on the intervention’s efficacy. Sample size of 10 is proposed logistically feasible given 
the 12 months of funding and clinical caseloads of the investigators. This data will be used to 

 
 
 
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calculate effect size and standard-deviation estimates for the endpoints described above. These 
estimates will be reported together with graphical and table summaries of the raw data, as 
relevant.” 
Inclusion /Exclusion Criteria   
Inclusion Criteria 
1. Male or female, ages 4 to 14 years old, inclusive. 
2. Has a diagnosis of cerebral palsy, of a diplegic, unilateral or bilateral distribution 
3. Uses walking as primary method of mobility at school, home, and the community, and 
has a GMFCS level of 1, 2 or 3.  
4. Barefoot gait pattern demonstrating leg segment misalignment consistent with the 
patterns in Figure 3. 
5. Family has resources to attend all study sessions (i.e. transportation/schedule). 
6. Currently wearing orthoses  or clinically appropriate to wear orthoses to enhance walking 
activity. 
7. Clinically deemed appropriate for a trial of the AFO-FC approach by the investigators 
Exclusion Criteria 
1. Non – English speaking. 
2. Foster children or wards of the state. 
3. Uses wheelchair or stroller mobility as a primary method of mobility, and uses walking 
either only at home, or only in therapy sessions. 
4. Severe visual impairment, such that the visual impairment itself functionally limits 
mobility.  
5. Any Orthopedic or Neurosurgery surgeries in the last 3 months. 
6. Any Phenol or Botox injections to the legs in the last 3 months.  
7. Uncontrolled seizure disorder, as defined as any seizure in the last 3 months which 
impacted their mobility skills and function. Seizures which did not affect their mobility are 
acceptable.  
8. Unable to understand directions sufficiently to complete the study assessments. 
9. Lower extremity fracture in the last 3 months. 
10. Planned surgery or changes to medication during the study period. 
Restrictions during the study: 
1. Any medications which affect muscle tone or movement disorders are at a stable dose for 
30 days prior to Baseline, and agree to maintain a stable dose during the protocol. If a 
dose change is needed, this will be recorded, and the child will stay on the study if the 
family still wishes to participate. 
2. Participants’ current physical therapy program will be continued throughout the protocol. 
 
 

 
 
 
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Study Duration and Timeline  
 
Study Period Months 
Study Task                 
1 
2-9 
10 
11 
12 
IRB 
 
 
 
 
 
Train Intervention/Assessment staff 
 
 
 
 
 
Recruitment/Enrollment 
 
 
 
 
 
Assessment/Intervention 
 
 
 
 
 
Post Treatment Follow up Assessments  
 
 
 
 
 
Data Analysis and Manuscript preparation 
 
 
 
 
 
The project will begin Oct 30, 2014 and end Sept 30, 2015 per published call for submission 
guidelines 
Study Visits and Procedures 
 
Baseline Visit 
Post Treatment Visit 
Study Week 
Occurs after  
1) Deemed clinically 
appropriate for AFO-FC  
2) Family expresses interest 
in participation 
3) Prior to fitting of new AFO-
FC prescription 
appointment  
 3 months post clinical 
fitting of new AFO-FC 
prescription appointment 
(+/- 2 weeks) 
Visit Number 
1 
2 
Informed Consent 
X 
 
Demographics 
X 
 
Medical and Surgical 
History 
X 
 
Gait Lab Assessment – 
Orthocare Innovations 
Biomechanics Lab 
X (Barefoot & with current 
AFO prescription/shoes) 
X (Barefoot & with AFO-FC)
Height  
X 
 
GMFCS 
X 
 
CFCS 
X 
 
MACS 
X 
 
ASKp 
X 
X 
Life-H  
X 
X 
OPUS 
X 
X 
Concomitant Medications 
X 
X 
Adverse Events 
 
X 
StepWatch Calibration/ 
Monitoring 
X 
X 
GPS Monitoring 
X 
X 
*ASKp is given to family to take home and complete on the day their monitors are returned. 
Recruitment and Pre – Screening 

 
 
 
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Participants will be approached regarding interest in the study, once deemed clinically 
appropriate for the AFO-FC prescription by Drs. Bjornson and Apkon. The investigators (Drs. 
Bjornson and Apkon) will ask family if they are interested in hearing about the study. They will 
then be contacted by the study CRA or Dr Bjornson to describe the study and  answer questions. 
Dr Bjornson will  coordinate and schedule baseline visit.  
Baseline Visit 
A Baseline visit will be scheduled after 1) deemed clinically appropriate for the AFO-FC 
prescription, 2) family expresses desire to participate and 3) before the final fitting of the new 
AFO-FC prescription.  
 
- 
Informed consent and assent and HIPAA authorization 
- 
Demographic and medical history questionnaire, include current medications, prior 
surgeries, and outside physical therapy. Questionnaire includes maternal level of 
education, whether the family owns or rents their home, type of orthotics used, and 
contact information for any community therapist caring for the child. 
- 
Gross Motor Classification System (GMFCS) scoring 
- 
Communication Function Classification system (CFCS) scoring 
- 
Manual Ability Classification system (MACS) scoring 
- 
Gait Lab Assessment – Orthocare Innovations Biomechanics Lab-barefoot & with current 
AFO/shoe prescription. 
- 
LIFE – H survey (completed by parent during visit ) 
- 
OPUS  Survey (completed by parent during visit ) 
- 
Activity Scale for Kids (ASKp) (sent home for parent to complete at end of wearing of 
monitors)  
- 
StepWatch: Calibration and fitting of the StepWatch activity monitor in a knit cuff on the 
left ankle. Children will be instructed to wear the StepWatch for the next 7 days while 
awake and not in the water, and to return it at their first treadmill training program 
session. Parents will be instructed to complete the ASKP on the 7th day of wearing the 
monitor and return by postage paid envelope.. 
- 
GPS: Children will be instructed in the use of the Global Positioning System (GPS) 
monitor at this visit with the same wearing and return protocol as the StepWatch. This 
device will be worn in a knit cuff on the right ankle. 
Clinical Intervention 
The child then has the appropriate clinical visits to cast, fabricate, fit and tune their new AFO-FC 
with a home walking program as appropriate. Consistency of clinical AFO-FC prescription will be 
addressed by the use of the published algorithm,1 (Appendix) currently utilized clinically by the 
investigators here at Seattle Children’s Hospital (SCH). All AFO portions of the AFO-FC devices 
will be casted at SCH and fabricated at Cascade DAFO (Dynamic Ankle Foot Orthoses), Inc., 
Ferndale WA. Families supply the shoes or footwear. The combined AFO with the footwear 
combinations FC will be fitted and tuned by the SCH orthotists and Dr Bjornson consistent with 
the published algorithm. 
Post Treatment Visit 
The single follow up visit will be conducted 3 months post clinical fitting of new AFO-FC 
prescription appointment (+/- 2 weeks).   

 
 
 
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- 
Record any adverse events, and update the concomitant medications and concomitant 
therapy form. 
- 
Gait Lab Assessment – Orthocare Innovations Biomechanics Laboratory-barefoot & with 
AFO-FC prescription. 
- 
LIFE – H survey (completed by parent during visit ) 
- 
OPUS  Survey (completed by parent during visit ) 
- 
Activity Scale for Kids (ASKp) (sent home for parent to complete at end of wearing of 
monitors)  
- 
StepWatch: Calibration and fitting of the StepWatch activity monitor in a knit cuff on the 
left ankle. Children will be instructed to wear the StepWatch for the next 7 days while 
awake and not in the water, and to return it at their first treadmill training program 
session. Parents will be instructed to complete the ASKP on the 7th day of wearing the 
monitor, and return by postage paid envelope. 
- 
GPS: Children will be instructed in the use of the Global Positioning System (GPS) 
monitor at this visit with the same wearing and return protocol as the StepWatch. This 
device will be worn in a knit cuff on the right ankle. 
Statistical Analysis Plan (See sample size above)  
The primary analysis for both aims will be descriptive for direction of effect and to generate effect 
size and power analysis for future multi-center R01 grants. 
Informed Consent Process 
The child’s parent/legal guardian will be approached for informed consent at the baseline visit. 
The study staff will review the consent form with the parent to explain study procedures, study 
purpose, voluntary nature of the study, and possible risks and/or benefits to the child and 
guardian.  If the child is 7 years old or older and thinks and makes decisions at least as well as a 
7 year old, then the child will complete an informed assent process with the study staff.  This may 
include drawing pictures, verbal explanations, reading portions of the assent form out loud, and 
other methods, to ensure that the child understands the study purpose, procedures, and voluntary 
nature of the study.  If the child agrees, he/she will sign an assent form, and have the researcher 
co – sign as indicated. Non – English speaking children will not be eligible, as there is not 
adequate interpreter support at the study locations. In addition, the activity surveys have not been 
validated in other languages. 
Privacy and Confidentiality 
Study data will be recorded on case report forms without any identifiers, coded with a study code, 
and stored in locked drawers in secure offices at Seattle Children’s Research Institute.  Study 
data will also be stored electronically in secure computer files and drives at Seattle Children’s 
Research Institute and through REDCap at SCRI accessible only by study staff Gait lab data 
containing only the study ID will be stored electronically in secure computer files and drives at 
Orthocare Innovations.  Anthropometric data collected as part of the gait analysis will be stored in 
locked file cabinets, by study ID. 

 
 
 
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Risk/Benefit 
Risk to participants  
Falling: There is a less likely, mild risk of falling during gait study assessments and treadmill 
training.  All walking tests will be conducted on indoor, on non-skid surfaces designed for gait 
analysis, to reduce the risk of injury resulting from falls. 
Muscle soreness and fatigue: There is a likely, mild risk of muscle soreness, and fatigue 
resulting from the exertion involved in the walk tests. 
Skin irritation: There is a rare, mild risk of skin irritation due to wearing the StepWatch monitor 
on the left leg and the GPS on the right ankle.  These monitors are worn with soft knit cuffs, 
similar to a sock, thus risk of irritation if rare. Families will be instructed to check the skin for any 
problems periodically, and to take a break if needed.   
Emotional distress or embarrassment: There is a rare, mild, risk of emotional distress or 
embarrassment due to completing the research surveys.  Parents will be informed that they can 
take a break or skip questions if they need to. 
Loss of privacy: We were concerned about the possible loss of privacy for children who 
complete the GPS monitoring.  To prevent this, all GPS data will be analyzed together, after the 
last child has completed study participation.  The GPS maps will not be available to children or 
their parents.  
Benefits to participants  
Participants will likely benefit from information collected within the study protocol (gait lab, walking 
activity and parent surveys).  This information has potential to inform the clinical orthotic 
management of the participant.  
Data Safety Monitoring 
The principal investigator will review any adverse events as they occur, and will report any 
possibly or definitely related adverse events to the IRB in accordance with their policies.  
Conflict of Interest 
None 
Publication and Presentation 
Results from this pilot study will be presented at appropriate professional conferences and 
submitted to appropriate journals.   
Data and/or Sample Sharing 
Data will not be shared with parties outside of the research team. 

 
 
 
Page 16 of 19 
 
APPENDIX 
 
 
 NORMAL SHANK KINEMATIC  IN 
STANCE PHASE? 
20-25° 
REC
10° 
REC
10° 
REC
10° 
INC
10° 
INC
20-25° 
INC
1st Rocker
3rd Rocker 
Terminal Stance
2nd Rocker
3rd Rocker 
Preswing
SWING PHASE / 
 INITIAL CONTACT 
PROBLEM? 
Posterior Leaf Spring or 
Hinged AFOFC 
FIXED ANKLE AFOFC with appropriate Angle of Ankle in AFO
TUNE ENTRY TO MST (IC, LR) 
by adjusting heel design to 
optimise shank kinematic and 
GRF alignment 
TUNE EXIT FROM MST (TST) 
by adjusting sole design  to 
optimise shank kinematic and 
GRF alignment 
Angular velocity of shank 
 during entry to MST needs to 
be increased by use of a 
positive heel? 
Flexible sole with flat or 
rounded sole profile 
produces optimal result?
 
TUNE MIDSTANCE by adjusting Heel Sole Differential of the AFOFC to determine the SHANK ANGLE TO FLOOR of the AFOFC 
 which produces optimal shank kinematic and GRF alignment. A useful starting point for tuning is 10-12° incline. 
TUNING PROCESS 
Trials by slow motion kinematic video, with or without kinetics, to optimise kinematic / kinetic gait parameters 
AFO DESIGN AT METATARSAL PHALANGEAL JOINTS
MTPJs fixed so as to prevent any inclination of shank 
 through use of anatomical 3rd rocker, B or C  
AFO DESIGN AT METATARSAL PHALANGEAL JOINTS 
MTPJs free to extend so as to enable inclination of shank 
through use of anatomical 3rd rocker,  A 
FOOTWEAR DESIGN 
Design which permits inclination of shank in TST = 
Flexible sole and sole profile design  which enables MTPJ 
extension and use of anatomical 3rd rocker 
FOOTWEAR DESIGN 
Design which resists excessive inclination of shank in TST=
Stiff sole and sole profile design which provides 
 simulated 3rd rocker 
Able to control shank kinematic in TST once 
ankle fixed sufficiently in AFO? 
AFO DESIGN AT ANKLE JOINT 
Ankle joint fixed 
 Dorsiflexion and incline resist design, B or C, 
depending on severity of gait abnormality 
AFO DESIGN AT ANKLE JOINT 
Ankle joint fixed 
Plantarflexion and recline resist 
 design, A or B  
ABNORMALITY OF SHANK KINEMATIC = 
EXCESSIVE INCLINE IN MST AND/OR TST 
ABNORMALITY OF SHANK KINEMATIC =  
INSUFFICIENT INCLINE IN MST AND/OR TST 
AFO not required 
unless other indications
Stiff sole with point loading 
rocker (optimised position 
and toe spring angle) 
produces optimal result?
Stiff sole with rocker sole 
profile (optimised position 
and toe spring angle) 
produces optimal result?
Plain heel produces 
 optimal result? 
Angular velocity of shank 
 during entry to MST needs  to 
be reduced by use of a  
negative or cushion heel? 
YES
YES
NO
NO
YES
NO
NO
NO
NO
NO
HEEL DESIGN
HEEL DESIGN
HEEL DESIGN
SOLE DESIGN
SOLE DESIGN
SOLE DESIGN
YES
YES
YES
YES
YES
YES
A
B
C
A CLINICAL ALGORITHM FOR THE DESIGN AND TUNING OF 
ANKLE-FOOT ORTHOSIS FOOTWEAR COMBINATIONS (AFOFCs) 
BASED ON SHANK KINEMATICS
Elaine Owen, MSc MCSP 
Child Development Centre, 
Holyhead Road, Bangor, 
LL67 0ES, UK
Eight years experience of designing and tuning  AFOFCs for a population of children with cerebral palsy, spina bifida 
and other conditions (n=141) on the ORLAU Transportable Video Vector Generator Gait Laboratory, which provides 
combined kinematic and kinetic analysis, has enabled the formulation of an algorithm which will facilitate the design and 
kinetic and/or kinematic tuning of AFOFCs.
telephone: +44 (0)1248-364700
email: lugger@talk21.com
References:
Owen E (2002) Shank angle to floor measures of tuned ‘ankle-foot orthosis footwear combinations’ used with children with cerebral palsy, spina bifida and other 
conditions. Gait & Posture 16, Supp 1, S132-S133                                                                                           
Owen E (2004) Shank angle to floor measures” and tuning of “Ankle-foot orthosis footwear combinations” for children with cerebral palsy, spina bifida and other 
conditions MSc thesis. Glasgow: Univ of  Strathclyde  (Available from Elaine Owen. email: lugger@talk21.com)                            
Owen E (2004) Tuning of ankle-foot orthosis combinations for children with cerebral palsy, spina bifida and other conditions Proceedings of ESMAC Seminars 2004 
(Available from Elaine Owen. email: lugger@talk21.com)                                                                       
Owen E, Bowers R, Meadows CB Tuning of AFO-Footwear Combinations for Neurological Disorders. Symposium in: Conference Proceedings. International Society for 
Prosthetics and Orthotics (ISPO) World Congress (2004) Hong Kong: ISPO
Owen E (2004) The point of ‘point-loading rockers’ in ankle-foot orthosis footwear combinations used with children with cerebral palsy, spina bifida and other conditions.
Gait & Posture 20S, S86
HEEL SOLE DIFFERENTIAL
Owen E (2002) and MSc Thesis (2004)
Plantarflexion     Plantigrade     Dorsiflexion
Published in: Gait and Posture 22S. S36-S37 (2005) ; Prosthetics and Orthotics International 34(3). 254-269 (2010)
 

 
 
 
Page 17 of 19 
 
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