title: Tai Chi training is effective in reducing balance impairments and falls in patients with Parkinson's disease.
abstract: OBJECTIVE
  Does Tai Chi improve postural control in patients with Parkinson's disease?
  
  
  METHODS
  Randomised, controlled trial and blinded outcome assessment.
  
  
  METHODS
  University clinic in USA.
  
  
  METHODS
  Individuals with Parkinson's disease (Hoehn and Yahr Stage 1-4) between the age of 40 and 85 years, and ability to walk with or without an assistive device were key inclusion criteria. Mini-Mental State examination score <24 and concurrent participation in other instructor-led exercise programs were key exclusion criteria. Randomisation of 195 participants allocated 65 to each of the Tai Chi, resistance, and stretching groups.
  
  
  METHODS
  The Tai Chi group underwent a Tai Chi program, the resistance group 8 to 10 leg muscle strengthening exercises, while the stretching group performed stretching exercises involving the upper body and lower extremities. All three groups trained for 24 weeks (60 minutes per session, two sessions per week).
  
  
  METHODS
  The primary outcomes were two indicators of postural stability - maximum excursion and directional control derived from dynamic posturography. The secondary outcomes were stride length, gait velocity, knee flexion and extension peak torque, functional reach, timed-up-and-go test, and motor section of the Unified Parkinson's Disease Rating Scale (UPDRS III). The outcomes were measured at baseline, at 12 and 24 weeks, and 3 months after termination of the intervention.
  
  
  RESULTS
  185 participants completed the study. At the end of the 24-week training period, the change in maximum excursion in the Tai Chi group was significantly more than that in the resistance group (by 5%, 95% CI 1.1 to 10.0) and the stretching group (by 12%, 95% CI 7.2 to 16.7). Direction control improved significantly more in the Tai Chi group compared with the resistance group (by 11%, 95% CI 3.9 to 17.0) and the control group (by 11%, 95% CI 5.5 to 17.3). The Tai Chi group also had significantly more improvement in stride length and functional reach than the other two groups. The change in knee flexion and extension peak torque, timed-up-and-go test, and UPDRS III score in the Tai Chi group was only significantly more than that in the stretching group, but not the resistance group. The falls incidence was also lower in the Tai Chi group than the stretching group during the 6-month training period (incidence-rate ratio: 0.33, 95% CI 0.16 to 0.71).
  
  
  CONCLUSIONS
  Tai Chi training is effective in reducing balance impairments in patients with mild to moderate Parkinson's disease.
authors: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China.
authors: William W N
authors: WW
authors: Tsang