Effect of Optokinetic Stimulation on the H Reflex in Humans

Abstract

We investigated the effects of optokinetic stimulation (OKS) on the soleus H reflex in ten healthy male subjects who were held in a fixed standing position. Upward and downward OKSs (60 degrees/s) were presented randomly. The H reflex amplitude decreased during upward OKSs and increased during downward ones (Kruskal-Wallis test, p < 0.02). Change in the H reflex amplitude was more marked during downward stimulation (p<0.0l). The H reflex was enhanced more during the acceleration phase of downward OKS than during the constant phase (p<0.01), but it fluctuated during the former phase. These results suggest that OKS affects a motoneurone activity and that information from the visual system modulates the condition of the motor program at the spinal level. © 1994, PHYSIOLOGICAL SOCIETY OF JAPAN. All rights reserved.