eng Science and Education Publishing American Journal of Sports Science and Medicine 2333-4606 2017-08-04 5 2 38 43 10.12691/ajssm-5-2-4 AJSSM2017524 article Hiroshi Hirai thh27155@osakafu-u.ac.jp 1 Shinichi Demura 2 Tamotsu Kitabayashi 3 Yoshimasa Matsuura 3 Faculty of Liberal Arts and Sciences, Osaka Prefecture University, Osaka, Japan College of Human and Social Sciences, Kanazawa University, Kanazawa, Japan Faculty of Science, Tokyo University of Science, Tokyo, Japan This study aimed to examine the effect of right-left or front-back vibration stimulus during standing on body sway. Subjects were 10 healthy young male adults. They had no evidence or known history of a gait, posture or skeletal disorder. After a weak vibratory stimulus (20 Hz) for 1 min, subjects stood under the strong stimulus (70 Hz) of front-back or right-left vibratory for 1 min. The subjects were measured body sway for 1 min before and after the above vibratory stimulus. Four body-sway factors (unit time sway, front-back sway, left-right sway, and the high frequency band power) were used as evaluation parameters. A significant decrease was found only in a unit time sway factor after vibratory stimulus. A significant difference between front-back and right-left vibratory stimuli was found only in a left-right sway factor and the latter stimulus produced a large change. In conclusion, even in the vibratory stimulus with the same intensity, body sway decreases after front-back stimulus, but increases after right-left stimulus. In short, the effect of vibratory stimulus on posture control system may differ by the vibratory direction. http://pubs.sciepub.com/ajssm/5/2/4/ajssm-5-2-4.pdf body sway vibration stimulus external stimulus