太极拳基础动作“野马分鬃”膝关节运动学、关节负荷及肌肉活动的特征比较

The Comparison of Knee Joint Kinematics,Joint Load and Muscle Activity Characteristics for Tai Chi Basic Action “the Wild Horse's Mane on Both Side”

目的:运用生物力学原理,通过对太极拳"野马分鬃"下肢的正确动作与错误动作的分析,了解其膝关节的运动学、关节负荷及肌肉活动的特征,并对可能造成太极拳膝关节损伤的原因进行探讨,为太极拳健身及如何有效预防练习过程中的膝关节损伤提供理论参考。方法:受试者为武英级女性一名,习武41年。动作选择为"野马分鬃"的正确动作与错误动作。采用Vicon运动捕捉系统、Kistler三维测力台和Delsys表面肌电采集系统分别对正确和错误动作的膝关节运动学、地面反作用力和股四头肌(股内肌、股外肌)及股后肌群(半腱肌和股二头肌)的肌电图(均方根振幅)进行同步测量,并采用SPSS 15统计软件,对不同动作的关节角度、关节力矩和肌肉活动等生物力学指标进行独立样本t检验。结果与结论:"野马分鬃"的错误动作各阶段用时、动作周期总用时显著高于正确动作,且错误动作右膝具有更大幅度的外展与外旋;"野马分鬃"动作的整个过程中,右膝关节处的伸肌力矩起主要作用,同时错误动作的膝外展和外旋力矩更大;错误动作在转脚时右腿股内肌、股外肌的活动显著更大,在一定程度上提示,错误的太极动作会对右膝产生更大的负荷,而长期这样训练很可能会造成运动员膝关节的损伤。

Objective：The aim of this study was to compare the biomechanical characteristics of lower extremity in conducting the＂part the wild horse＇s mane on both side＂of Tai Chi maneuver in a correct and a wrong form.In order to find the possible cause of the knee injure of Tai Chi and prevent such kind of injure effectively,the kinematics,joint loading,and muscle activity of the knee joint was therefore explored.Methods：the subject was a top-level female athlete（41 years of practicing Tai Chi）.The test movement was a Tai Chi maneuver called＂part the wild horse＇s mane on both side＂（in a correct and a wrong form）.A Vicon system,two Kistler forceplates,and a Delsys surface EMG system were synchronously used to collect the kinematics,ground reaction forces,and EMG activity from the quadriceps and the hamstring muscles of the knee joint.Paired T-test was applied to compare the differences（joint angle,joint torque,and muscle activity）between the two forms.Results Conclusion：The time of each stage and the movement circle was significantly higher in wrong form of Tai Chi compared with the correct form.Meanwhile,a significant larger angle in knee joint abduction and internal rotation was showed in the wrong from.During the whole procedure of the movement,a dominated torque was showed in the extensor of the right knee joint.However,a significant larger torque in the abduction and external rotation of the knee joint was also observed.During the foot switch,the vastus medialis and vastus lateralis muscle activity were significantly greater in the wrong form,which showed a resistance to the great loading on the knee caused by the wrong movement.The above results implied that the knee injury would be induced due to the wrong form during a long-term Tai Chi exercise.