Study On The Biomechanical Characteristics Of The Lower Limbs In Tai Chi Athletes With Patellofemoral Pain Syndrome

PURPOSE: Patellofemoral pain syndrome is primarily caused by excessive pressure on the patellofemoral joint. In Tai Chi practice, the lower extremity has multiple rotational movements. If the knee and ankle joints are not aligned during training, incorrect movements can cause patellar displacement. The main objective of this study is to identify issues in the stepping movements of Tai Chi through gait analysis, reduce injuries caused by incorrect movements in Tai Chi practice, and promote the popularization and dissemination of Tai Chi routines in competitive and public practice. METHODS: Our study primarily selected 24 professional athletes of level two or above from the School of Martial Arts at Beijing Sport University. An infrared high-speed motion capture system and a three-dimensional force platform (Kistler) were used to synchronously collect kinematic and dynamic indicators during the stepping motion of Yang-style Tai Chi. RESULTS: At the end of the turn phase, the treatment group increased the abduction angle of the right hip than the control group. In the experimental group, the maximum pressure occurred during the upward step motion when the knee joint adduction angle was 12°, the external rotation angle was 35°, and the flexion angle was 60°. In contrast, the control group experienced maximum pressure when the knee joint adduction angle was 13°, the external rotation angle was 31°, and the flexion angle was 77°. There is a significant difference in the maximum pressure on the sagittal plane of the knee joint between the treatment group and the control group. The average maximum pressure in the experimental group is 169 N, while the average maximum pressure in the control group is 123 N. CONCLUSIONS: Tai Chi athletes with patellofemoral pain syndrome have a larger valgus angle of the knee joint during the stepping motion. Tai Chi athletes with patellofemoral pain syndrome experience the greatest pressure and are more likely to feel pain when the knee joint flexion angle is at 60° during the stepping motion. Tai Chi athletes with patellofemoral pain syndrome have smaller hip joint abduction angles and ankle joint dorsiflexion angles during stepping movements. Supported by: "Key Technologies for Physical Training and Training Monitoring in Winter Sports" under the "Science and Technology for the Winter Olympics" Special Program (Project No.: 2019YFF0301600).