Background: Downslope walking (DSW) is an eccentric-based exercise intervention that promotes neuroplasticity of spinal reflex circuitry by inducing depression of Soleus Hoffman (H)-reflexes in young, neurologically unimpaired adults.
Objective: The objective of the study was to evaluate the effects of DSW on spinal excitability (SE) and walking function (WF) in people with multiple sclerosis (PwMS).
Methods: Our study comprised two experiments on 12 PwMS (11 women; 45.3±11.8 years). Experiment 1 evaluated acute effects of a single 20-minute session of treadmill walking at three different walking grades on SE, 0% or level walking (LW), - 7.5% DSW, and - 15% DSW. Experiment 2 evaluated the effects of 6 sessions of DSW, at - 7.5% DSW (with second session being - 15% DSW) on SE and WF.
Results: Experiment 1 showed significantly greater acute % H-reflex depression following - 15% DSW compared to LW (p = 0.02) and - 7.5% DSW (p = 0.05). Experiment 2 demonstrated significant improvements in WF. PwMS who showed greater acute H-reflex depression during the - 15% DSW session also demonstrated greater physical activity, long-distance WF, and the ability to have greater H-reflex depression after DSW training. Significant changes were not observed in regards to SE.
Conclusions: Though significant changes were not observed in SE after DSW training, we observed an improvement in WF which merits further investigation of DSW in PwMS.
Keywords: Treadmill training; neuroplasticity; spasticity; spinal excitability.