目的 揭示运动姿势对关节功能的影响，对深入了解膝关节疼痛机理具有积极意义。本项研究考察了太极拳运动姿势对膝关节载荷的影响及肌肉协调收缩策略。方法 募集20名具有3年以上健康太极拳习练者，借助Qualisys红外高速运动捕捉系统和AMTI BP400600三维测力台，采集了“上步弓步”动作支撑腿内收角、胫骨角、关节力、关节力矩等参数，通过Lifemod仿真方法获取了股四头肌和腓肠肌肌肉力量。比较了惯用步、外展步和内收步肌肉力量表现、募集模式和激活方式特征。结果 外展步胫骨角和内收力增大而内收步不变；外展步股内肌、半膜半腱肌及外侧腓肠肌力量增大；内收步股外肌和内侧腓肠肌力量增强，腓肠肌比股四头肌被优先激活，肌群募集方式发生改变。结论 优先激活腓肠肌是太极拳动作下肢肌肉活动的基本特征，腓肠肌的作用可能不是补偿，而是先导。踝关节运动方式可能是触发腓肠肌被优先激活的原因之一。太极拳运动姿势改变肌肉力量募集方式，影响膝关节功能，规范动作可作为骨性关节炎运动疗法借鉴，具有临床应用意义。
Objective Revealing the effect of exercise posture on joint function is of positive significance for in-depth understanding of the mechanism of knee pain. This study investigated the influence of Tai Chi exercise posture on knee joint load and the strategy of coordinated muscle contraction.Method recruited 20 Tai Chi practitioners with more than 3 years of Tai Chi practice, using Qualisys high-speed motion capture system and AMTI BP400600 three-dimensional force plate, collected adduction angle, tibial angle, joint force, joint torque and of the supporting leg of the "The step lunge" movement, and obtained the quadriceps and gastrocnemius muscle strength through Lifemod simulation software. The muscle strength performance, recruitment mode and activation method of Baseline gait, Toe-out gait and Toe-in gait were compared.Results The tibial angle and adduction force increased in the Toe-out gait but the Toe-in gait remained unchanged; the strength of the medial femoris, Semimembranosus, semitendinosus and lateral gastrocnemius muscle increased in the Toe-out step; the external femoral muscle and medial gastrocnemius muscle increased in the Toe-in step,The gastrocnemius muscle is preferentially activated than the quadriceps muscle, and the way of muscle recruitment changes. Conclusion Prioritizing the activation of the gastrocnemius is the basic feature of the lower limb muscle activity in Tai Chi movements. The role of the gastrocnemius may not be compensation, but lead. The way of movement of the ankle joint may be one of the reasons that triggers the preferential activation of the gastrocnemius muscle. Tai Chi exercise posture changes the way of muscle force recruitment and affects knee joint function. Standardized movements can be used as a reference for osteoarthritis exercise therapy and have clinical application significance.