Improving postural control using a portable plantar pressure-based vibrotactile biofeedback system

A portable and lightweight vibrotactile biofeedback system is introduced here which acts as a real-time balance aid. The biofeedback system provided users with vibrotactile stimulation based on changes in plantar pressure distribution. An experiment was conducted to investigate its effectiveness in improvement of postural control. A Romberg test was performed requesting the subjects to stand as still as possible, while the degree of body sway was measured by a force platform. Two young healthy subjects and one older healthy subject participated in the study. A wearing wool socks and eye-closed intervention was used to simulate reduced sensory input, and the effect of provision of vibrotactile feedback was studied. The experiment was conducted in 3 conditions: 1) bare feet, eyes open (baseline), 2) wearing 5 layers of wool socks, eyes closed, 3) wearing 5 layers of socks, eyes closed, with biofeedback system turned-on. The range, root mean square (RMS) and coefficient of variance (CV) of center of pressure (COP) were studied. Results indicated a significant increase of postural sway after the intervention of reducing sensory inputs, and a considerable reduction of postural sway upon using the vibrotactile feedback reminding body motion in four directions. These results suggested that vibrotactile biofeedback system is effective in improving postural control of subjects. Future studies about the effects of this biofeedback system on dynamic balance control and gait are needed.