Abstract: AnyBody simulation software was used to calculate the kinematics, dynamics and muscle strength of lower limbs of 24-form Taichi (TC) movements (wild horse split bristle, repulse monkey, cloud hand) during march. The biomechanical characteristics of lower limbs of 24-form Taijiquan practitioners at different levels were analyzed. Subjects: A total of 30 subjects were selected and divided into two groups. One group (16 Men) was college students who participated in University courses, which was defined as the experiment group. The other group (14 men) came from College of physical education and sports and major TC, practised TC over a long time (3 years or more), which was defined as the professional group. Methods: BTS three-dimensional motion capture system, three-dimensional force plate and surface electromyography test system were used to synchronously collect the data of Parting the wild horse's mane, Repulse monkey, Cloud hands. AnyBody human body modeling and simulation system (AMS) was used to calculate and analyze the kinematics, dynamics and muscle stress of lower limbs at the peak moment of knee joint force during the three movements. Results: At the peak force in the vertical axis direction of knee joint, In the movement of Parting the wild horse's mane, Repulse monkey and Cloud hands, the angle of ankle flexion, hip adduction and abduction in the professional group were significantly lower than those in the general group (P < 0.05), and the angle of hip rotation was significantly higher than that in the general group (P < 0.01). The stress of the three joints in the sagittal axis direction in the professional group was significantly higher than that in the general group (P < 0.05), and the stress of the hip joint in the frontal and vertical axis direction was significantly lower than that in the professional group (P < 0.01). major muscle groups around the hip joint and thigh exerted less strength, while the muscles around the leg, hip joint and thigh exerted more strength (P＜0.01). Conclusions and suggestions: the experiment group showed a larger ankle flexion angle and a smaller rotation and abduction angle; a smaller force in the sagittal axis direction and a greater force in the frontal axis direction; major muscle groups around the hip joint and thigh exerted less strength, while the muscles around the leg, hip joint and thigh exerted more strength. Beginners should pay attention to the rotation of the trunk and control the angle of hip joint adduction and abduction in the process of Taijiquan exercise. Beginners should persist in long-term Taijiquan exercise and feel the muscle strength of the major muscles around the hip joint and trunk during the exercise, so as to promote the control ability of posture in the process of Taijiquan exercise.

Key words: Sports Biomechanics, AnyBody simulation software, 24-form Taichi