Upper limb muscle strength and wheelchair-related abilities following an exoskeleton-assisted walking programme in individuals with chronic spinal cord injury: An exploratory study.

Objectives: To measure the potential effects of an overground exoskeleton-assisted walking programme on upper limb strength and mass, as well as on wheelchair propulsion performances and abilities in individuals with chronic spinal cord injury.

Design: Prospective, single-group, pre-post intervention study.

Participants: Ten individuals with chronic (≥ 18 months) spinal cord injury who use a wheelchair as their primary mode of locomotion and who had little-to-no motor function in the lower limbs.

Methods: Individuals completed a progressive 16-week exoskeleton-assisted walking programme (34 × 1-h sessions, 1-3 sessions/week). Upper limb muscle strength was measured with dynamometers (isokinetic, Jamar). Upper limb lean mass (dual-energy X-ray absorptiometry) was used to calculate relative strength. Field tests (20-m wheelchair propulsion, and slalom test) and the Wheelchair Skills Test Questionnaire determined performances and abilities. Wilcoxon signed-rank tests were used with the following criteria: p < 0.1, effect size ≥ 0.5, and relative variation > 5%.

Results: Only natural velocity during the 20-m wheelchair propulsion test (i.e., fundamental wheelchair ability) changed following the intervention (p = 0.01, effect size = 0.82, relative variation = +14.5%).

Conclusion: Overall, upper limb muscle function did not significantly and meaningfully change following the exoskeleton-assisted walking programme in this population. Additional research is needed to verify how changes in training volume would affect strength and advanced wheelchair-related abilities and performance, as well as the response in individuals who are deconditioned or novices to wheelchair use (e.g., subacute spinal cord injury).