title: A randomised controlled trial of Tai Chi and resistance exercise on bone health, muscle strength and balance in community-living elderly people.
abstract: BACKGROUND
  The beneficial role of exercise in improving bone mineral density, muscle strength and balance, has been documented predominantly in younger populations. These findings may not apply to elderly populations with limited ability to perform exercises of high intensity.
  
  
  OBJECTIVE
  To examine the effects of Tai Chi (TC) and resistance exercise (RTE) on bone mineral density (BMD), muscle strength, balance and flexibility in community living elderly people.
  
  
  METHODS
  Randomised controlled trial, using blocked randomization with stratification by sex.
  
  
  METHODS
  A community in the New Territories Region of Hong Kong, China.
  
  
  METHODS
  One hundred eighty subjects (90 men, 90 women) aged 65-74, were recruited through advertisements in community centres.
  
  
  METHODS
  Subjects were assigned to participate in TC, RTE three times a week, or no intervention (C) for 12 months. Measurements were carried out at baseline, 6 and 12 months. Analyses of covariance (ANCOVA) adjusted for age, and baseline values of variables that were significantly different between groups: i.e. smoking and flexibility for men; quadriceps strength for women.
  
  
  RESULTS
  Compliance was high (TC 81%, RTE 76%). In women, both TC and RTE groups had less BMD loss at total hip compared with controls. No effect was observed in men. No difference in either balance, flexibility or the number of falls was observed between either intervention or controls after 12 months.
  
  
  CONCLUSIONS
  The beneficial effects of TC or RTE on musculoskeletal health are modest and may not translate into better clinical outcomes.
authors.affiliation: Chinese University of Hong Kong, Department of Medicine and Therapeutics, Department of Community and Family Medicine, Shatin, NT, Hong Kong. jeanwoowong@cuhk.edu.hk
authors.forename: Jean
authors.initials: J
authors.lastname: Woo
authors.forename: Athena
authors.initials: A
authors.lastname: Hong
authors.forename: Edith
authors.initials: E
authors.lastname: Lau
authors.forename: Henry
authors.initials: H
authors.lastname: Lynn
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control*; D000368:Aged; D000375:Aging / Q000502:physiology; D000843:Ankle Joint / Q000502:physiology; D015519:Bone Density; D015444:Exercise / Q000502:physiology; D005260:Female; D018737:Hand Strength; D006621:Hip Joint / Q000502:physiology; D006723:Hong Kong; D006801:Humans; D008297:Male; D053580:Muscle Strength; D004856:Postural Balance; D016059:Range of Motion, Articular; D026302:Tai Ji; D013997:Time Factors