太极拳练习伴膝关节疼痛者下肢生物力学表现的三维运动分析

Three-dimensional motion analysis of lower limb biomechanical performance in Tai Chi practitioners accompanied by knee joint pain

背景:太极拳练习出现膝关节疼痛者不在少数,而目前关于太极拳练习伴膝关节疼痛者行拳特征的生物力学研究较少。目的:运用三维运动分析系统比较太极拳练习伴膝关节疼痛者与健康练习者在太极拳习练时下肢生物力学的差异。方法:选择太极拳练习伴膝关节疼痛者6例为试验组,健康练习者6例为对照组。采用三维运动分析系统,记录两组受试者进行“搂膝拗步”时的运动学和动力学,比较在地面反作用力特征时刻下的动作特征。地面反作用力特征时刻包括左、右搂膝拗步推进期波峰时刻(T1、T5),右搂膝拗步后坐转向期波谷时刻(T2),右搂膝拗步单足支撑期第一、第二波峰时刻(T3、T4)。结果与结论:①运动学参数:两组的步长、步宽和质心高度的差异无显著性意义(P>0.05);与对照组相比,试验组在T1和T5时,后支撑腿髋外展角度更大(P<0.05);T2、T3的左膝关节及T5的右膝关节内收(P<0.05);在T2和T4的右膝关节外展角度更小(P<0.05);②动力学参数:与对照组相比,试验组在T3、T4和T5的垂直轴地面反作用力更小(P<0.05);在T1和T5的前支撑腿髋后伸力矩更小(P<0.05);在T5的前支撑腿伴更小的髋外旋力矩(P<0.05);在T1时左膝关节的总支撑力矩贡献度更大(P<0.01);③结果表明,相对于健康练习者,练习时伴膝关节疼痛者减少了对地面的作用力;两组训练者运动学动力学的不同主要集中在髋关节和膝关节,伴膝关节疼痛练习者的膝关节呈较大的内收,且弓步推进期的前支撑腿表现出髋关节伸展旋转不足、膝关节总支撑力矩贡献度更大;伴膝关节疼痛的训练者进行太极拳再训练时,需考虑从练习者髋关节和膝关节的运动模式进行调整。

BACKGROUND:Tai Chi practice can cause knee pain symptoms in many individuals.There is currently less research on the characteristics of practitioners with knee pain from a biomechanical view.OBJECTIVE:To explore the differences in biomechanical characteristics of the lower limbs in Tai Chi practice by three-dimensional motion system between practitioners who experience knee pain and healthy practitioners.METHODS:Six practitioners with knee pain were selected into an experimental group,while six healthy practitioners were chosen into a control group.Threedimensional motion capture system was used to record the kinematics and dynamics of the lower limbs during Brush Knee and Twist Step in both groups.The motion characteristics at the characteristic moment of ground reaction force were compared.The characteristic moment of ground reaction force included the front support leg ground reaction force peak time in the left/right Brush Knee and Twist Step propulsion period(T1/T5),the left leg ground reaction force trough time in the right Brush Knee and Twist Step recoil turning period(T2),the ground reaction force first peak time in the right Brush Knee and Twist Step single support period(T3),the ground reaction force second peak time in the right Brush Knee and Twist Step single support period(T4).RESULTS AND CONCLUSION:(1)Kinematic parameters:The difference in step length,step width and centroid height was not statistically significant between the two groups(P>0.05).Compared with the control group,the experimental group had a greater hip abduction angle of the posterior support leg(P<0.05)at T1 and T5;the left knee adducted at T2 and T3,and the right knee adducted at T5(P<0.05);a smaller abduction angle in right knee at T2 and T4(P<0.05).(2)Kinetic parameters:Compared with the control group,the experimental group had lower vertical ground reaction force(P<0.05)at T3,T4 and T5;a smaller hip extension moment of the front support leg(P<0.05)at T1 and T5;a lower hip rotation moment of the front support leg(P<0.05)at T5.The total support moment contribution of knee joint in the experimental group was greater(P<0.01)at T1.(3)The results suggested that compared with the healthy trainers,the practitioners with knee pain symptom reduced their force on the ground.The differences in kinematic and kinetic parameters between the two groups were concentrated in the hip and knee joints.They showed less hip extension and rotation,larger knee adduction,and larger the total support moment contribution of the knee joint.Therefore,when retraining Tai Chi for trainers with knee pain,it is necessary to consider the adjustment from the movement patterns of the practitioner’s hip and knee joints.