Abstract: ObjectiveTo explore changes of the reacting force of the ankle joint (J) and the achilles tendon force (A) in the sagittal plane in a weight-bearing leg in a bout of the simplified-style Taijiquan exercise.MethodsJ and A determined from 30 healthy young males were analyzed using the simplified free body method.ResultsJ and A increased during exercise, J produced by movement 10, 14 and A produced by movement 8, 12 were about 2.4 times and 0.7 times body weight of 67.3kg respectively.ConclusionTaijiquan can increase the force of ligment and muscle around the ankle joint, especially that of triceps muscle of calf, and it is helpful for remaining the stability of the ankle structure.

Key words: Taijiquan, reacting force, achilles tendon force, ankle joint