Tai Chi improves standing balance control under reduced or conflicting sensory conditions

OBJECTIVE: To investigate the effects of long-term Tai Chi practice on balance control when healthy elderly Tai Chi practitioners stood under reduced or conflicting somatosensory, visual, and vestibular conditions, as compared with healthy elderly non-Tai Chi practitioners and young subjects. DESIGN: Cross-sectional study. SETTING: University-based rehabilitation center in Hong Kong. PARTICIPANTS: Twenty elderly Tai Chi practitioners (mean experience +/- standard deviation, 7.2+/-7.2 y) were compared with 20 elderly non-Tai Chi practitioners and 20 young, healthy university students. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The amplitude of anteroposterior body sway under different somatosensory, visual, and vestibular conditions was measured using computerized dynamic posturography, whereby subjects underwent 6 combinations of visual and support surface conditions. RESULTS: The Tai Chi practitioners had significantly better balance control than the non-Tai Chi subjects in the visual and vestibular ratios, but not in the somatosensory ratio. Furthermore, there were no significant differences in any of these 3 sensory ratios when the Tai Chi practitioners were compared with those of the young, healthy subjects. CONCLUSIONS: Long-term Tai Chi practice improved balance control in the elderly population when there was an increased reliance on the visual and vestibular systems during stance. Of particular interest is that our elderly Tai Chi practitioners attained the same level of balance control performance as did young, healthy subjects when standing under reduced or conflicting somatosensory, visual, and vestibular conditions.