Fall prevention by vibration stimuli to planta pedis

Considering the aging population, the prevention of falls will become increasingly importance. One of the causes of an elderly people fall is the incrimination of a body sway. Therefore we thought about stimuli to receptor to decrease body sway. The purpose of this study is to suppress a body sway by giving planta pedis stimuli by single frequency vibration. Our developed equipment can give vibration stimuli to planta pedis on three points from 50 to 400Hz. The vibration stimuli points are heel, the root of big toe and the root of a little toe. The intensity of stimuli is set to 90% of the smallest stimuli intensity that the subject can feel it. In other words a subject does not feel vibration. The frequency of stimuli is 200Hz, 225Hz, 250Hz, 275Hz, 300Hz. We judged the effect of vibration stimuli by time duration of one-leg standing without vision and the trajectory of body sway. The results showed that the time duration extended and the trajectory of body sway decreased. Most effective frequency was 225Hz. Our conclusion is that the vibration stimuli to planta pedis are useful for fall prevention of elderly people.