Restoring Walking With a Powered Exoskeleton After Spinal Cord Injury

Not Applicable

Completed

Conditions: Spinal Cord Injury

Interventions: Device: ReWalk

Registration Number: NCT02322125

Lead Sponsor: University of Alberta

Brief Summary: 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: 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.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 12

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

Study & Design

Study Type: INTERVENTIONAL

Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
ReWalk training	ReWalk	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.

Primary Outcome Measures

Name	Time	Method
Physiological Cost Index (PCI) Ratio	End of training:12-14 weeks from baseline	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)

Secondary Outcome Measures

Name	Time	Method
10 Meter Walk Test	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)	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.
Limits of Stability - Sitting	Baseline, Mid point-6 weeks from baseline, End training:12-14 weeks from baseline	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.
Spinal Cord Assessment Tool for Spastic Reflexes (SCATS)	Baseline, midpoint:6 weeks from baseline, end training:12-14 weeks from baseline	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
Motor Evoked Potentials	Baseline, End training:12-14 weeks from baseline	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
Sitting Sway	Baseline, Mid-point:6 weeks from baseline, End training:12-14 weeks from baseline	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.
Change From Baseline in Manual Muscle Test at End of Training	Baseline, end training:12 -14 weeks from baseline	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 1. palpable or visible contraction 2. active movement, gravity eliminated 3. active movement, against gravity 4. active movement, against some resistance 5. active movement, against full resistance
Max Distance	End of training:12-14 weeks from baseline	The maximum distance walked without a rest for up to one hour.
McGill Pain Questionnaire	Baseline, midpoint:6 weeks from baseline, end training:12-14 weeks from baseline	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.