Effect of a virtual walking and exercise-based intervention on muscle strength and activation in people with incomplete spinal cord injury

This study aims to assess the effect of combining virtual walking (VW) therapy with a physical exercise (PE) program compared to PE alone on lower limb strength and muscle activation in people with incomplete spinal cord injury (iSCI). 38 participants performed 3 sessions/week during 6 weeks of Experimental Intervention (EI): VW and PE; or Control intervention (CI): Placebo-VW and PE. Strength and muscle activation of main lower limb muscles were assessed. EI group exhibited a general strength increase after intervention (T2), (16.31-34.72 N), and maintained this improvement up to 1-month-follow-up (T3) for hip abduction and extension movements. The CI group only showed improvements in hip abduction and extension movements (18.34 (7.13) N and 19.98 (9.60) N, respectively). EI group also exhibited an increase of activation in all agonistic muscles in T2 (36.02-20.24 mu V), except gastrocnemius. Gastrocnemius and rectus femoris activation as antagonistic decreased during dorsal flexion (- 14.28 (5.61) mu V) and hip extension (- 14.78 [6.11] mu V), respectively. CI group only showed an activation increase of agonistic muscles of hip abduction and extension (22.16 (9.80) mu V and 28.82 (9.14) mu V, respectively), without changes in antagonistic activation. VW could enhance the PE effects regarding muscle strength and activation in people with iSCI.Registration number: NCT04809987.