Testing an Adjustable Ankle Orthosis During Walking in Cerebral Palsy

Early Phase 1

Completed

• Conditions: Cerebral Palsy
• Interventions: Device: Differential and adjustable stiffness AFO (DAS-AFO)

• Registration Number: NCT06262191
• Lead Sponsor: Northern Arizona University

Brief Summary

This study seeks to determine how an adjustable stiffness ankle braces affects walking performance and biomechanics in cerebral palsy.

Detailed Description

Our first aim is to confirm that the differential and adjustable stiffness (DAS) AFO improves plantarflexor push-off power and range of motion compared to standard (physician prescribed) AFOs during walking in CP.

Our second aim is to confirm that the differential and adjustable stiffness (DAS) AFO improves plantarflexor muscle activity while maintaining improved posture compared to standard AFOs during walking in CP.

Our third aim is to validate the need and usability of real-time stiffness adjustment during play and school activities; obtain feedback from the children, their parents, and orthotists to design the MVP.

Study Timeline

• Study First Submitted: 2024-01-29
• Study First Submitted QC: 2024-02-08
• Study First Posted: 2024-02-15
• Study Start: 2024-05-01
• Primary Completion: 2024-06-01
• Study Completion: 2024-06-01
• Results First Submitted: 2025-02-05
• Status Verified: 2025-05
• Results First Submitted QC: 2025-05-22
• Last Update Submitted: 2025-05-22
• Results First Posted: 2025-05-25
• Last Update Posted: 2025-05-25

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 11

Inclusion Criteria

• Age between 8-35 years old, inclusive
• Diagnosis of cerebral palsy (CP)
• Gross motor functional classification score level I, II, or III
• Physician-prescribed AFOs of common design (i.e., rigid molded thermoplastic)
• Ability to walk for 6 minutes on a treadmill
• At least 20° of passive plantar-flexion range of motion
• No concurrent treatment other than those assigned during the study
• No condition other than CP that would affect safe participation
• No surgery within 6 months of participation.

Exclusion Criteria

-Excessive knee flexion during walking caused by CP

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Study group	Differential and adjustable stiffness AFO (DAS-AFO)	Participants will walk with the new AFO, their own AFOs, and no AFOs.

Primary Outcome Measures

Name	Time	Method
Change in Muscle Activity	day 1	Change in integrated soleus electromyography (mV/mV) muscle activity during stance phase of walking.
Change in Metabolic Cost of Transport	day 1	Change in metabolic cost of transport during walking. To calculate the metabolic cost of transport, the standing baseline metabolic rate for each participant and each trial was subtracted from their walking metabolic rate to estimate the net metabolic rate of walking. Next, we normalized the net metabolic rate of walking by each participant's body mass (m) and walking speed to calculate the metabolic cost of transport (J/kg\*m), averaged over the last two minutes of each condition.
Change in Ankle Power	1 day during walking	Change in peak ankle power during stance phase measured in w/kg. Ankle kinematics and kinetics were calculated in OpenSim using the collected three-dimensional motion capture and the ground reaction forces. The joint kinematics and ground reaction forces were filtered using a low pass fourth order recursive Butterworth filter with a cut-off frequency of 6 Hz before being used to calculate joint kinetics. The ground reaction forces were collected using two force places associated with the instrumented treadmill (Bertec Corp, Columbus, USA) collected at 1200 Hz. The resultant joint kinetics were then further filtered using the same filtering parameters. Ankle joint power was calculated as the product of the joint moment and joint angular velocity.

Trial Locations

Locations (1)

Northern Arizona University; 🇺🇸 Flagstaff, Arizona, United States