Restoring Walking With a Powered Exoskeleton After Spinal Cord Injury

Study Overview
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Brief Summary
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Powered exoskeletons have emerged recently, promising to offer walking to individuals with severe spinal cord injury who are unable to walk. We will use the ReWalk exoskeleton to train walking in individuals with chronic, severe spinal cord injury (SCI). We will determine the characteristics of individuals who most benefit from such training, and identify the neuroplasticity induced by the training. We will further determine the feasibility of the ReWalk for home and community ambulation.

Detailed Description
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A prospective, pilot, cohort study design will recruit participants to train intensively for a 3 month period. The training sessions will be documented in detail, including number of steps taken, speed of walking, distance of walking. Once walking speed has plateaued, we will evaluate the feasibility of using the device in a home-like environment and in the community. At the end of this study, we will have a good idea of the capability of the ReWalk to assist walking in those with severe spinal cord injury. We will better understand which individuals are most likely to benefit from the ReWalk. We will know how training in the ReWalk changes the neural connections between the brain and the spinal cord so that we can better guide the training protocol. Finally, we will identify limitations of the ReWalk for home and community use, so that exoskeletons can be improved in the future to maximize their benefit to people with spinal cord injury.

Official Title
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Restoring Walking With a Powered Exoskeleton After Complete and Sever Incomplete Spinal Cord Injury

Conditions
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Spinal Cord Injury

Intervention / Treatment
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* Device: ReWalk


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: non-progressive spinal cord injury ≥1 year post-injury Body height between 5'3 and 6'4 Body weight ≤82 kg Uses wheelchair as primary mode of mobility If able to walk, walks at ≤0.4 m/s Arm strength sufficient to control forearm crutches Agree to attend intensive training of 1.5 hr/day, 4 days/wk for 14 weeks, plus testing pre and post training of approximately 2 weeks each Exclusion Criteria: Contractures at the hip, knee or ankle that interferes with fitting into the ReWalk Fractures within the last 2 years Osteoporosis in the legs (t-score ≤-3.0) Severe postural hypotension Severe spasticity that interferes with use of the ReWalk Active pressure sores Pregnancy Severe head injury Conditions that preclude intensive exercise (such as high blood pressure) Presence of conditions contraindicated for transcranial magnetic stimulation

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: ReWalk training<br>ReWalk exoskeleton training: 1.5 hr/day, 4 days/week, for 12-14 weeks (approximately 50 training sessions). Participants will progress through the following: sit-to-stand, stand-to-sit, standing balance and weight shift, walking on smooth ground, stopping, turning while walking, walking on rough ground, ascending and descending slopes, ascending and descending steps and curbs. | Device: ReWalk<br>* Intensive training with the ReWalk to negotiate smooth ground, rough terrain indoors and outdoors, ascending and descending slopes and steps, in a home setting and in the community.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Physiological Cost Index (PCI) Ratio | PCI is defined as the change in heart rate from the average at rest to the average in the last two minutes of the 6 minute walk test is divided by the average speed during the last two minutes of walking to give a measure of heartbeats/minute. The ratio between this measure while walking in the Rewalk and the same measure while performing the test using a wheelchair will be calculated. (Walk/wheelchair) | End of training:12-14 weeks from baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 10 Meter Walk Test | Walking is timed over a 10 m section while the participant walks in the ReWalk in a 40 m hallway at the fastest safe speed possible. | End of training (at 12 weeks for 10 participants and 6 weeks for 1) and at follow-up (2-3 months from end of training) | 
| Max Distance | The maximum distance walked without a rest for up to one hour. | End of training:12-14 weeks from baseline | 
| Limits of Stability - Sitting | While sitting/standing on a force plate, the participant will lean in 8 directions guided by a computer screen with feedback of the center of pressure. The sum of the maximum fore-aft and left right excursions was calculated. The changes from baseline to mid point of training, the end of the training phase (12 weeks) were calculated. | Baseline, Mid point-6 weeks from baseline, End training:12-14 weeks from baseline | 
| Sitting Sway | Participants will sit on a force plate with feet unsupported, arms crossed over the chest and eyes closed. The trajectory of the center of pressure is measured for a maximum of 30 seconds or until balance is lost. | Baseline, Mid-point:6 weeks from baseline, End training:12-14 weeks from baseline | 
| McGill Pain Questionnaire | Paper/pencil questionnaire in which participant selects words that describe current pain. Words are divide into 20 subgroups and ranked within each group. A total score is tabulated by adding the number associated with the highest ranking word from each subgroup. Score range is from 0 to 73 with higher scores indicating greater pain. | Baseline, midpoint:6 weeks from baseline, end training:12-14 weeks from baseline | 
| Spinal Cord Assessment Tool for Spastic Reflexes (SCATS) | Response to 3 standardized tests: stretch of ankle plantarflexors, pin prick to the sole of the foot, stretch of the hip and knee flexors scored from 1 to 3. The scores form both lower extremities were summed (total score: no spasticity = 0; maximum spasticity = 36 | Baseline, midpoint:6 weeks from baseline, end training:12-14 weeks from baseline | 
| Motor Evoked Potentials | Single pulse transcranial magnetic stimulation is delivered over the vertex to induce motor evoked potentials in the back extensor muscles. Electrical responses in paraspinal muscles were recorded at 8 levels spanning the injury. The peak to peak amplitude of the response was averaged over rials with background muscle contraction of 10 to 40 microvolts | Baseline, End training:12-14 weeks from baseline | 
| Change From Baseline in Manual Muscle Test at End of Training | Five muscle groups in each lower extremity (hip flexors, knee extensors, ankle dorsiflexors, extensor of the big toe, and ankle plantarflexors) were tested as per the American Spinal Injury Association Impairment scale. Each muscle group was scored on a scale ranging from 0-5, where 0/5 indicates no muscle activity and is the lowest score and is considered to be a worse outcome. A score of 5/5 indicates normal strength and is considered the better outcome. The scores for all 10 muscle groups were summed so that the maximum score is 50. Change from baseline in Manual Muscle Test to end of training was calculated. 0= total paralysis palpable or visible contraction active movement, gravity eliminated active movement, against gravity active movement, against some resistance active movement, against full resistance | Baseline, end training:12 -14 weeks from baseline | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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walking, locomotion, rehabilitation