Objective: To compare phase- and task-dependent H-reflex modulation in standing and walking in 2 spinal cord injury (SCI) groups with and without a walker. Methods: Fourteen subjects with American Spinal Injury Association Impairment Scale D SCI (40±10 years) participated. Tibial nerve was stimulated to evoke 15 H-reflexes (at M-wave 7%-13% of maximum-M). Results: H-reflex was greater in the walker group during stance (but not standing/swing). Conclusion: Differences in H-reflex modulation between groups walking with and without a walker may be explained by sensory mechanism that enhances central excitation, difference in motor activation levels between groups, and other complex mechanisms that influence balance or stability.
Keywords: soleus H-reflex; spinal cord injury; standing; walker; walking.