The Short-Term Effect of Slope Walking on Soleus H-Reflexes in People with Multiple Sclerosis

Abstract Downslope walking (DSW) causes H-reflex depression in healthy adults, and thus may hold promise for inducing spinal reflex plasticity in people with Multiple Sclerosis (PwMS). The study purpose was to test the hypothesis that DSW will cause acute depression of spinal excitability in PwMS. Soleus H-reflexes were measured in PwMS ( n  = 18) before and after 20 min of treadmill walking during three visits. Participants walked on a different slope each visit [level: 0% level walking (LW), upslope: +7.5% treadmill walking with an upslope (USW) or downslope: −7.5% (DSW)]. The soleus H max / M max ratio was used to measure spinal excitability. Heart rate and ratings of perceived exertion (RPE) were measured during walking. DSW induced the largest change in spinal excitability (a 26.7% reduction in soleus H max / M max ( p  = 0.001)), although LW also reduced H max / M max (-5.3%, p  = 0.05). Heart rate ( p