The effects on sensorimotor performance and balance with Tai Chi training

Objectives: To compare the effects of short-term and long-term Tai Chi training on the sensorimotor and balance performance of able-bodied subjects. Design: A nonrandomized cross-sectional controlled trial. Setting: Sport laboratory. Participants: Forty-eight healthy subjects, 16 with 3 months of experience in Tai Chi training, 16 with I to 3 years of experience in Tai Chi training, and 16 with no experience in Tai Chi training. Intervention: Experimental. Main Outcome Measures: The reflex contraction latencies (reaction time) of medial hamstrings and gastrocnemius after perturbation, the active knee joint angle-repositioning error, and the balance time on a tilt board were measured and analyzed with 1-way analysis of covariance. Significant results were further analyzed with post hoc linear contrasts. Results: Long-term Tai Chi practitioners had a significantly faster reflex reaction time in hamstrings (P<.000) and gastrocnemius (P=.043) muscles and a longer balance time on a tilt board (P<.000) than short-term Tai Chi practitioners and nonpractitioners. Both long- and short-term Tai Chi practitioners had significantly less knee joint angle-repositioning error than nonpractitioners (P=.001 and P=.027, respectively). Conclusions: Tai Chi training of more than I year might have the benefits of faster hamstrings and gastrocnemius reflex reaction and improved knee joint position sense (JPS). These changes might be associated with an improved dynamic standing balance. Better knee JPS was shown in subjects with 3 months of Tai Chi practice, but this had not led to a significant improvement in balance.