title: Effects of long-term tai chi practice on balance and H-reflex characteristics.
abstract: The purpose of the present study was to examine the effects of long-term Tai Chi practice on postural balance and H-reflex. Sixteen healthy volunteers, eight with three or more years of experience in Tai Chi training (Tai Chi Group-TCG), and eight with no experience in Tai Chi training (Control Group-CG) participated in the study. Postural sways were measured under four experimental conditions: (1) Standing still with eyes open (EO); (2) Standing still with eyes closed (EC); (3) Standing and turning head to left and right with eyes open (EOT); and (4) Standing and turning head to left and right with eyes closed (ECT). Paired reflex depression (PRD) of the soleus muscle was measured under two conditions: supine and standing. Less significant postural sway was observed in the TCG than in the CG under four conditions including EO, EC, EOT, and ECT (p < 0.01). The TCG demonstrated 14.1%, 30.6%, 33.3% and 22.7% less postural sway, respectively. Significant PRD change from a supine to standing position was observed between TCG and CG (p < 0.05). A significant correlation between PRD change (from supine to standing) and years of Tai Chi practice was observed (r = 0.80, p < 0.05). The findings of this study support the positive effects of Tai Chi exercise on balance control under different conditions. Long-term Tai Chi exercisers also demonstrated different reflex modulation from a supine to standing position, and long-term Tai Chi practice may lead to a change of PRD modulation as neuroadaptation.
authors.affiliation: Department of Health Promotion and Physical Education, Ithaca College, Ithaca, NY 14850, USA. hguan@ithaca.edu
authors.forename: Hongwei
authors.initials: H
authors.lastname: Guan
authors.forename: David M
authors.initials: DM
authors.lastname: Koceja
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015444:Exercise / Q000502:physiology*; D005123:Eye; D006181:H-Reflex / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D026302:Tai Ji; D013997:Time Factors; D014796:Visual Perception