Gait Adaptation and Biofeedback for Cerebral Palsy

Study Overview
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Brief Summary
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This research aims to evaluate walking function in children with cerebral palsy (CP). The researchers want to understand how children with CP adapt and learn new ways of moving. They have previously found that measuring how a person controls their muscles is important for assessing walking ability and response to interventions. In these studies, they will adjust the treadmill belt speeds and/or provide real-time feedback to evaluate how a child can alter their movement. The feedback will include a wearable exoskeleton that provides resistance to the ankle and audio and visual cues based on sensors that record muscle activity. This research will investigate three goals: first, to measure how children with CP adapt their walking; second, to see if repeated training can improve adaptation rates; and third, to determine if individual differences in adaptation relate to improvements in walking function after training. This research will help develop better treatments to enhance walking capacity and performance for children with CP.

Detailed Description
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Prior research has shown that children with cerebral palsy (CP) use simplified motor control strategies compared to nondisabled (ND) peers, and that these differences in motor control are associated with walking function. While we can quantify motor control during activities like walking, the processes by which a child with CP adapts and learns new movement patterns are poorly understood. This research will use two paradigms to evaluate adaptation and motor learning in children with CP: walking on a split-belt treadmill and responding to multimodal biofeedback. Walking on a split-belt treadmill, which has two belts set at different speeds to induce asymmetry during walking, has been commonly used to evaluate adaptation in other clinical populations. Responding to multimodal feedback can also be used to evaluate an individual's capacity to adapt their walking pattern. This research will use a real-time multimodal feedback system that targets plantarflexor activity, a key muscle group that is often impaired in CP. Sensorimotor feedback will be provided using a lightweight, body-worn robotic device that provides adaptive ankle resistance and step-by-step audiovisual feedback will be provided based on muscle activity from the plantarflexors using a visual display and audible tone. This research will quantify adaptation rate (e.g., change in soleus activity or step length symmetry) in response to these perturbations, and observe the impact of repeated practice on walking function (e.g., change in walking speed). The specific aims are to: Aim-1: Quantify adaptation rates in children with CP. We will quantify adaptation rate in response to three perturbation experiments: split-belt treadmill walking, sensorimotor feedback, and audiovisual feedback. The primary hypotheses are that children with CP will exhibit reduced adaptation rates compared to ND peers, and that adaptation rates will be associated with function (Gross Motor Function Measure, GMFM-66). Aim-2: Determine whether adaptation rates change in response to repeated feedback training. Children with CP will be randomized into three groups: sensorimotor feedback, audiovisual feedback, and sensorimotor and audiovisual feedback. Each group will undergo six weeks of training (20-min, 2x/week). The primary hypothesis is that adaptation rates will increase with repeated exposures to feedback training. Aim-3: Determine whether walking function improves after repeated practice. Gait analysis will be performed at follow-up to evaluate whether feedback training induced motor learning and improved walking function. The primary hypotheses are that training will improve muscle, joint, and whole-body performance, with the greatest improvements from combined sensorimotor and audiovisual feedback.

Official Title
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Quantifying Patient-specific Changes in Neuromuscular Control in Cerebral Palsy: Adaptation and Biofeedback During Gait

Conditions
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Cerebral Palsy

Intervention / Treatment
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* Device: Biomotum Spark: Robotic ankle resistance
* Device: Audiovisual Biofeedback


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of bilateral cerebral palsy that impacts both legs Gross Motor Functional Classification System Level II No surgery or lower-extremity injuries in prior 12 months No botulinum toxin injections in prior 3 months No prior selective dorsal rhizotomy surgery No history of seizures or cardiac conditions that would preclude walking on a treadmill for 20 minutes No current pain that hinders walking

Ages Eligible for Study
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Minimum Age: 7 Years
Maximum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Audiovisual Biofeedback<br>Participants will complete 12 sessions (20 minutes of walking on a treadmill) over a 6-8 week period while receiving audiovisual biofeedback based on the muscle activity of their ankle plantarflexors. The visual feedback will be provided on a screen with a bar showing real-time muscle activity and the audio feedback will be a sound played when they reach the target level of muscle activity. | Device: Audiovisual Biofeedback<br>* Electromyography recordings from the plantarflexor muscles are used to provide audio feedback via a sound that plays when muscle activity is above target and a visual bar that displays real-time muscle activity.<br>|
| Experimental: Sensorimotor Biofeedback<br>Participants will complete 12 sessions (20 minutes of walking on a treadmill) over a 6-8 week period while receiving sensorimotor biofeedback with an ankle exoskeleton that provides resistance to ankle plantarflexion during the stance phase of gait. | Device: Biomotum Spark: Robotic ankle resistance<br>* Robotic ankle exoskeleton that provides resistance to ankle plantarflexion.<br>|
| Experimental: Audiovisual + Sensorimotor Biofeedback<br>Participants will complete 12 sessions (20 minutes of walking on a treadmill) over a 6-8 week period while receiving both audiovisual and sensorimotor biofeedback. Sensorimotor biofeedback will be provided with an ankle exoskeleton that provides resistance to ankle plantarflexion during the stance phase of gait. The visual feedback will be provided on a screen with a bar showing real-time muscle activity and the audio feedback will be a sound played when they reach the target level of muscle activity from the plantarflexors. | Device: Biomotum Spark: Robotic ankle resistance<br>* Robotic ankle exoskeleton that provides resistance to ankle plantarflexion.<br>Device: Audiovisual Biofeedback<br>* Electromyography recordings from the plantarflexor muscles are used to provide audio feedback via a sound that plays when muscle activity is above target and a visual bar that displays real-time muscle activity.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Soleus Muscle Activity | Average stance-phase magnitude of soleus muscle activity from electromyography recording measured during gait at 1-month follow-up. | Change from baseline at 1-month after intervention. | 
| Change in Peak Ankle Power | Average peak ankle power evaluated during gait. | Change from baseline at 1-month after intervention. | 
| Change in Self-Selected Walking Speed | Average overground walking speed. | Change from baseline at 1-month after intervention. | 
| Change in Dynamic Motor Control During Walking (Walk-DMC) | The total variance account for by one muscle synergy calculated from electromyography recordings during gait. | Change from baseline at 1-month after intervention. | 
| Change in Gait Deviation Index (GDI) | Deviation in gait kinematics compared to nondisabled gait. | Change from baseline at 1-month after intervention. | 
| Change in Gross Motor Function Measure - 66 (GMFM-66) Parts D & E | Assessment tool designed and evaluated to measure changes in gross motor function. Parts D & E focus on standing, walking, jumping, and running function. | Change from baseline at 1-month after intervention. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Gait, Rehabilitation