Objective: To evaluate the training effect of a Tai Chi Chuan (TCC) program
on knee extensor muscular strength and endurance in elderly individuals.
Design: Before-after trial.
Setting: Community setting.
Participants: Forty-one community dwelling subjects aged 61.1 +/- 9.8 years
undertook a TCC program. Nine dropped out during the study. Pretraining an
d posttraining measurements were obtained from 15 men and 17 women.
Intervention: Subjects participated in a 6-month TCC program. Each session
consisted of 20 minutes of warm-up, 24 minutes of structured TCC training,
and 10 minutes of cool-down exercises.
Main Outcome Measures: Peak torque of dominant and nondominant knee extenso
rs was tested at speeds of 60 degrees, 180 degrees, and 240 degrees/sec con
centrically and eccentrically. Muscular endurance of the knee extensor was
tested at the speed of 180 degrees/sec.
Results: In the group of men, concentric knee extensor peak torque increase
d by 15.1% to 20.0% and eccentric peak torque increased by 15.1% to 23.7%.
The group of women also showed increases, ranging from 13.5% to 21.8% in co
ncentric peak torque, and 18.3% to 23.8% in eccentric peak torque. In addit
ion, the knee extensor endurance ratio increased by 9.6% to 18.8% in the me
n and 10.1% to 14.6% in the women.
Conclusion: TCC training may enhance muscular strength and endurance of kne
e extensors in elderly individuals.