Systematic reviews of t'ai chi: an overview
	.	Myeong Soo Lee1,2, Edzard Ernst2
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Author Affiliations
	.	1Brain Disease Research Centre, Korea Institute of Oriental Medicine, Daejeon, South Korea
	.	2Complementary Medicine, Peninsula Medical School, University of Exeter, Exeter, UK
	.	Correspondence to Myeong Soo Lee, Brain Disease Research Centre, Korea Institute of Oriental Medicine, 461-24, Jeonmin-dong, Yuseong-gu, Daejeon 305-811, South Korea; drmslee@gmail.com
		Accepted 8 February 2011
		Published Online First 16 May 2011
Abstract
Several systematic reviews (SRs) have assessed the effectiveness of t'ai chi for many conditions including hypertension, osteoarthritis and fall prevention; however, their conclusions have been contradictory. The aim of this overview was to critically evaluate the SRs of t'ai chi for any improvement of medical conditions or clinical symptoms. English, Chinese and Korean electronic databases were searched for relevant articles, and data were extracted according to predefined criteria; 35 SRs met our inclusion criteria. They were related to the following conditions: cancer, older people, Parkinson's disease, musculoskeletal pain, osteoarthritis, rheumatoid arthritis (RA), muscle strength and flexibility, improving aerobic capacity, cardiovascular disease and risk factors, lowering resting blood pressure, osteoporosis or bone mineral density, type 2 diabetes, psychological health, fall prevention and improving balance, and any chronic conditions. In several instances, the conclusions of these articles were contradictory. Relatively clear evidence emerged to suggest that t'ai chi is effective for fall prevention and improving psychological health and was associated with general health benefits for older people. However, t'ai chi seems to be ineffective for the symptomatic treatment of cancer and RA. In conclusion, many SRs of t'ai chi have recently been published; however, the evidence is convincingly positive only for fall prevention and for improvement of psychological health.