Document Type

Article

Publication Date

2-25-2015

Abstract

Reciprocal Ia inhibition constitutes a key segmental neuronal pathway for coordination of antagonist muscles. In this study, we investigated the soleus H-reflex and reciprocal inhibition exerted from flexor group Ia afferents on soleus motoneurons during standing and walking in 15 healthy subjects following transcranial magnetic stimulation (TMS). The effects of separate TMS or deep peroneal nerve (DPN) stimulation and the effects of combined (TMS + DPN) stimuli on the soleus H-reflex were assessed during standing and at mid- and late stance phases of walking. Subthreshold TMS induced short-latency facilitation on the soleus H-reflex that was present during standing and at midstance but not at late stance of walking. Reciprocal inhibition was increased during standing and at late stance but not at the midstance phase of walking. The effects of combined TMS and DPN stimuli on the soleus H-reflex significantly changed between tasks, resulting in an extra facilitation of the soleus H-reflex during standing and not during walking. Our findings indicate that corticospinal inputs and Ia inhibitory interneurons interact at the spinal level in a task-dependent manner, and that corticospinal modulation of reciprocal Ia inhibition is stronger during standing than during walking. ª

Comments

This article originally appeared in Physiological Reports, available at DOI: 10.14814/phy2.12276

© 2015 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

 
 

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