Retraining walking over ground in a powered exoskeleton after spinal cord injury: a prospective cohort study to examine functional gains and neuroplasticity

Abstract

BackgroundPowered exoskeletons provide a way to stand and walk for people with severe spinal cord injury. Here, we used the ReWalk exoskeleton to determine the training dosage required for walking proficiency, the sensory and motor changes in the nervous system with training, and the functionality of the device in a home-like environment.MethodsParticipants with chronic (> 1 yr) motor complete or incomplete spinal cord injury, who were primarily wheelchair users, were trained to walk in the ReWalk for 12 weeks. Measures were taken before, during, immediately after, and 2–3 months after training. Measures included walking progression, sitting balance, skin sensation, spasticity, and strength of the corticospinal tracts.ResultsTwelve participants were enrolled with 10 completing training. Training progression and walking ability: The progression in training indicated about 45 sessions to reach 80% of final performance in training. By the end of training, participants walked at speeds of 0.28–0.60 m/s, and distances of 0.74–1.97 km in 1 h. The effort of walking was about 3.3 times that for manual wheelchair propulsion. One non-walker with an incomplete injury became a walker without the ReWalk after training. Sensory and motor measures: Sitting balance was improved in some, as seen from the limits of stability and sway speed. Neuropathic pain showed no long term changes. Change in spasticity was mixed with suggestion of differences between those with high versus low spasticity prior to training. The strength of motor pathways from the brain to back extensor muscles remained unchanged. Adverse events: Minor adverse events were encountered by the participants and trainer (skin abrasions, non-injurious falls). Field testing: The majority of participants could walk on uneven surfaces outdoors. Some limitations were encountered in home-like environments.ConclusionFor individuals with severe SCI, walking proficiency in the ReWalk requires about 45 sessions of training. The training was accompanied by functional improvements in some, especially in people with incomplete injuries.Trial registrationNCT02322125 Registered 22 December 2014.Electronic supplementary materialThe online version of this article (10.1186/s12984-019-0585-x) contains supplementary material, which is available to authorized users.

Effects of Wearable Powered Exoskeletal Training on Functional Mobility, Physiological Health and Quality of Life in Non-ambulatory Spinal Cord Injury Patients

“…Reduced spasticity following exoskeleton training in SCI patients has been reported in previous studies. 17 19 27 28 Mirbagheri et al 29 reported that robotic-assisted gait training in SCI patients reduced spasticity by modulation of intrinsic joint properties and stretch reflex stiffness. The reduction in spasticity in this study might be explained by the fact that the exoskeleton enables chronic SCI patients to perform bipedal ambulation and move through the normal range of motion of multiple lower extremity joints.…”

Exoskeleton home and community use in people with complete spinal cord injury

“…In patients without (the potential for) ambulatory capacity (i.e., complete SCI), who are wheelchair users for their mobility, an exoskeleton can be used as an assistive device in order to walk. However, exoskeleton use as an assistive device without physical assistance from a trainer requires an intensive training period 7 – 9 . In our previous study, we have shown that more than half of the participants with a complete SCI could use an exoskeleton independent of assistance under supervision of a buddy after 24 training sessions 9 .…”

“…The potential of an exoskeleton for gait restoration was demonstrated by improving unassisted gait speed and walking distance after exoskeleton training 6 . Furthermore, two non-walkers with an incomplete SCI became walkers after exoskeleton training 4,7 . Hence, for people with incomplete SCI, 'therapeutic' exoskeleton use has the potential to improve ambulatory capacity independent of the exoskeleton.…”

The Role of Supraspinal Structures for Recovery after SCI: From Motor Dysfunction to Mental Health

“…Functional improvements were reported, especially in people with incomplete injuries. Spasticity had mixed changes, suggesting differences between high versus low spasticity prior to training [88].…”