Citation

Tanaka Y. Motor Control 2015; 19(3): 242-249.

Affiliation

Faculty of Education and Regional Studies, University of Fukui, Fukui, Japan.

Copyright

(Copyright © 2015, Human Kinetics Publishers)

DOI

10.1123/mc.2013-0104

PMID

25587695

Abstract

This study investigated the effect of psychological pressure on spinal reflex excitability. Thirteen participants performed a balancing task by standing on a balance disk with one foot. After six practice trials, they performed one non-pressure and one pressure trial involving a performance-contingent cash reward or punishment. Stress responses were successfully induced; state anxiety, mental effort, and heart rates all increased under pressure. Soleus Hoffmann reflex amplitude in the pressure trial was significantly smaller than in the non-pressure trial. This modification of spinal reflexes may be caused by presynaptic inhibition under the control of higher central nerve excitation under pressure. This change did not prevent 12 of the 13 participants from successfully completing the postural control task under pressure. These results suggest that Hoffmann reflex inhibition would contribute to optimal postural control under stressful situations.

Language: en