Acute kinematic and neurophysiological effects of treadmill and overground walking in Parkinson's disease

BACKGROUND: The use of the treadmill as a gait rehabilitation tool has provided novel options for treatment of gait impairments in Parkinson's Disease (PD). However, the neural mechanisms underlying these therapeutic effects in PD remain unknown and whether any therapeutic effects from treadmill training can be reproduced on overground walking. OBJECTIVE: To examine the immediate short-term effects of a single session of treadmill and overground walking on gait, spinal and corticospinal parameters in PD. METHODS: PD participants (N = 15) were evaluated in two separate sessions under two walking conditions: walking over a treadmill and walking overground. Overground walking performance, the Soleus H-reflex, Reciprocal Ia-Inhibition, Intracortical Facilitation (ICF) and Short Intracortical Inhibition (SICI), were evaluated before and after each condition. RESULTS: Gait speed and stride length improved in post-treadmill compared with pre-treadmill. No significant changes in these gait parameters were found for the pre vs. post-overground condition. ICF values and Hmax/Mmax ratio decreased after, compared with before, the two walking conditions. CONCLUSIONS: Treadmill walking, but not overground walking, lead to an improvement in the stride length and gait speed in the PD patients without evidence of different modulation on spinal and corticospinal parameters.