Age-related differences in efficiency of visual and vibrotactile biofeedback for balance improvement

OBJECTIVES: The purpose of this study was to determine the effectiveness of visual (VF) and vibrotactile (TF) biofeedback obtained from the lower trunk (L5) tilts signal and their combination (VF+TF) in reducing postural sway in young and elderly people. METHODS: Twenty healthy elderly subjects (8 males, mean age 74 years) and 20 healthy young subjects (7 males, mean age 27 years) were tested in biofeedback conditions (VF, TF and VF+TF) and in control conditions (eyes open) during the stance on firm and foam surface. RESULTS: Young adults significantly reduced their postural sway (RMS – root mean square of CoP and L5 tilts) in all biofeedback conditions. Elderly people reduced their postural sway in conditions when the visual biofeedback was presented (VF and VF+TF) mostly during stance on foam surface. During TF conditions, an increase of velocity in anteriorposterior direction occurred. CONCLUSION: Similar effectiveness of visual and combined biofeedback points out stronger influence of visual biofeedback because vibrotactile biofeedback alone had minimal effect in reducing postural sway in elderly. Used method of vibrotactile biofeedback was probably not enough intuitive for the body position control of elderly. An increase of velocity in anterior-posterior direction during TF conditions indicates higher voluntary activation of balance control in order to minimize amplitudes of postural sway.