HOW THE CENTRAL CONTROL SYSTEM ADAPTS TO ACUTE WHOLE-BODY VIBRATION STIMULUS 12

This study investigated the effects of high- and low-frequency acute whole-body vibration (WBV) on postural control ability. Sixteen male students from the Faculty of Sport Science voluntarily participated in this study. [Methods] WBV stimuli were applied using the following parameters: (1) frequency: 30 or 40 Hz; (2) stance: static squat position; (3) amplitude: 4 mm; (4) knee flexion angle: 120°; and duration: 60 s. The medio-lateral ground reaction force (MLGRF) and anterio-posterior ground reaction force (APGRF) were measured on a force platform. The results showed that static WBV stimulation at 4 mm in amplitude at low and high frequencies resulted in different postural adaptations (p<0.05). The APGRF and MLGRF were higher at 30 Hz than at 40 Hz, and a rapid exponential decline in the post-vibration values was observed within the first 10 seconds of stimulation at 30 Hz or 40 Hz at 4 mm. After the initial 10 seconds, these forces were maintained until the end of the 60-second stimulation period. The present findings support that somatosensory stimulation at 30 Hz and 4 mm induced long-term effects on the control of postural sway. Alternatively, somatosensory stimulation more rapidly adapted to the vibration at 40 Hz and 4 mm. It may be concluded that WBV at 40 Hz and 4 mm can rapidly provide beneficial effects to the elderly, for whom postural control is very important, for the treatment of chronic conditions such as Parkinson’s disease, osteoporosis, and post-menopausal conditions or for the enhancement of athletic performance.