... community based tai- chi trials have a usual care, education, or social activity control group, and not a comparison exercise group as used in our study The effect of tai- chi on falls among community ... performance and early disease J Clin Epidemiol 2001;54:889e901 17 Day L, Hill K, Jolley D, et al Impact of tai- chi on impairment, functional limitation and disability A randomized controlled trial Arch ... Similarly, in the second study, there was no effect shown in of the falls analyses (survival analysis, falls rates) among a frail group after a 15-week program, compared with conventional physical...