Evaluating Wearable Robotic Assistance on Gait

Study Overview
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Brief Summary
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The overarching goal of this study is to improve mobility in individuals with movement disorders through advances in wearable assistance (i.e. powered orthoses).

Detailed Description
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Design (Aim 1): To test the hypothesis for Aim 1, we will systematically adjust the magnitude of powered ankle assistance as ambulatory individuals with CP walk on over-ground walking at self-selected speeds, on a treadmill at set speeds, and on stair-stepping machine at a constant rate. The bi-directional ankle device will provide dorsi-flexion assistance if the participant has foot-drop. We will compare powered assistance to each participant's baseline walking condition (shod or AFOs); we will recruit a cohort where half of the participants walk with prescribed AFOs. We will measure three-dimensional motion capture, electromyography, and metabolic respiration data, and assess subject perception of exertion and benefit during the walking and stair trials for each level of assistance. Data collection will take place following a practice visit. Design (Aim 2): To test the hypotheses for Aim 2, the same individuals with gait deficits from CP from Aim 1 will be randomly selected to complete 30 minutes of over-ground gait training with individually-tuned plantar-flexor assistance 4x/week for 1 week or 2x/week for 2 weeks. The magnitude of assistance during training will be set at the amount that maximized metabolic cost of transport during level walking in Aim 1 for each participant and kept constant.

Official Title
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Evaluating Wearable Robotic Assistance on Gait Mechanics and Energetics in Individuals With Neurological Impairment

Conditions
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Cerebral Palsy

Intervention / Treatment
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* Device: powered orthosis


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age between 5 and 35 years old, inclusive. Either a healthy volunteer or a diagnosis of a neurologically-based walking disorder due to stroke, spinal cord injury, Parkinson's disease, or cerebral palsy. Must be able to understand and follow simple directions based on parent report and clinical observation during the history and physical examination. Able to provide verbal assent, if appropriate. If the participant is non-verbal, parental interpretation of gesticulation for assent will be used. The ability to read and understand English. Able to walk at least 30 feet with or without a walking aid (GMFCS Level I-III for individuals with cerebral palsy) Exclusion Criteria: • Any neurological, musculoskeletal or cardiorespiratory injury, health condition ( including pregnancy), or diagnosis other than stroke, spinal cord injury, Parkinson's disease or cerebral palsy that would affect the ability to walk as directed for short periods of time.

Ages Eligible for Study
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Minimum Age: 5 Years
Maximum Age: 35 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: Device Feasibility
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Interventional Model Description: Feasibility assessment of powered orthosis assistance and resistance during walking.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Exoskeleton Assistance Higher Frequency<br>Walking with exoskeleton assistance to make walking easier. | Device: powered orthosis<br>* Novel powered leg brace to provide assistance during walking.<br>* Other names: exoskeleton;|
| Experimental: Exoskeleton Assistance Lower Frequency<br>Walking with exoskeleton assistance to make walking easier. | Device: powered orthosis<br>* Novel powered leg brace to provide assistance during walking.<br>* Other names: exoskeleton;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The metabolic energy required to walk | Metabolic energy required to walk will be measured using a portable metabolic measurement system (Cosmed K5). Units: J/kg/m | Through study completion, an average of 8 weeks. | 
| Walking speed | Walking speed measured over-ground or on a treadmill. Units: m/s | Through study completion, an average of 8 weeks. | 
| Muscle activity | Muscle activity during walking will be measured using electromyography electrodes. Units: mV | Through study completion, an average of 8 weeks. | 
| Lower-extremity joint angles | A motion capture system will be used to measure the posture of the body during walking. Units: Degrees | Through study completion, an average of 8 weeks. | 
| Lower extremity joint moments | A motion capture system and force plates will be used to measure the forces produced by the muscles of the body during walking. Units: Nm | Through study completion, an average of 8 weeks. | 
| Change in energy required to walk | We will compare the metabolic energy required to walk. Units: % change | Through study completion, an average of 8 weeks. | 
| Change in 6 minute walk test | We will compare the distance covered in 6 minutes of walking. Units: % change | Through study completion, an average of 8 weeks. | 
| Change in muscle activity profile | We will compare the muscle activity profile. Units: % change | Through study completion, an average of 8 weeks. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cadence | Number of steps per minute will be measured. Units: steps/min | Through study completion, an average of 8 weeks. |