太极拳转体动作中下肢关节活动顺序性和肌肉力表现及肌肉激活特征

目的 分析太极拳转体与弓步动作中下肢关节活动顺序性、肌肉力表现和肌肉激活程度的差异,揭示太极拳转体动作的特征。 方法 募集 20 名练习时长超过 3 年的健康太极拳练习者,采用三维运动捕捉系统、测力台和表面肌电同步采集转体与弓步两种动作运动学、动力学和肌肉激活信息,并通过 OpenSim 仿真软件获取下肢肌力。结果 与弓步相比,转体动作髋、踝关节外旋幅度显著增大;膝关节外展和外旋力矩显著增大,股二头肌、半腱肌和内外侧腓肠肌峰值肌力显著增强,股二头肌、内外侧腓肠肌峰值肌力时刻显著提前,而股内外侧肌和胫骨前肌峰值肌力显著减小,胫骨前肌肌力最早达到峰值;股二头肌、股内外侧肌和内侧腓肠肌的平均激活水平和激活时间显著增加。 结论 太极拳转体动作由踝、髋关节依次转动组成,肌肉力表现的独特性在于重心两次转移致使支撑腿内外侧肌力曲线呈双峰型,因为全足着地延迟方式引发了腓肠肌与股四头肌激活顺序和肌肉平均激活水平改变。研究结果提示全足着地延迟方式具有调节肌肉激活顺序的作用,合理利用有助于提升临床康复效果。

Lower Limb Joint Activity, Muscle Strength Performance and Muscle Activation of Tai Chi Twist Movement

Objective To analyze the differences of activity sequence, muscle force performance and muscle activation in lower limb joints between Tai Chi lunge and twist movement, so as to to reveal the characteristics of Tai Chi twist movement. Methods Twenty healthy Tai Chi practitioners who have practiced Tai Chi for more than 3 years were recruited. The kinematic, kinetic and muscle activation of two movements were collected simultaneously using a three-dimensional ( 3D ) motion capture system, force platform and surface electromyography, and the lower limb muscle force was obtained by OpenSim simulation software. Results Compared with lunge movement, there was a significant increase in lateral rotation amplitude of hip and ankle joint in twist movement. The knee abduction and external rotation torque increased significantly. The peak muscle strength of biceps femoris, semitendinosus and medial and lateral gastrocnemius increased, and the time of peak muscle strength of biceps femoris and medial and lateral gastrocnemius was significantly advanced, while the peak muscle strength of vastus medialis, vastus lateralis and tibial anterior muscles decreased, the tibialis anterior muscle strength reached its earliest peak. The average activation levels and activation time of biceps femoris, vastus medialis, vastus lateralis, and medial and lateral gastrocnemius significantly increased. Conclusions Tai Chi twist movement is composed of ankle and hip joint rotation in turn. The uniqueness o fmuscle strength lies in that the center of gravity is shifted twice, which makes muscle strength curve of the vastus medialis and vastus lateralis of the supporting leg to be bimodal. The activation sequence and average activation level of gastrocnemius and quadriceps femoris are changed due to the delay of full foot landing. The results indicate that the full foot landing delay mode has the effect of regulating the sequence of muscle activation, and rational use is helpful to improve the clinical rehabilitation effect