膝关节内侧移位者髋部肌肉力量及表面肌电特征研究

关键词：膝关节内侧移位  臀大肌  臀中肌  髋关节内收肌

Keywords:medial knee displacement  gluteus maximus  gluteus medius  hip adductor

摘要：

      摘要 目的：通过研究单腿下蹲时膝关节内侧移位者髋部肌肉力量及表面肌电特征，探讨膝关节内侧移位的发生机制及膝关节损伤的防治方法。 方法：从男性青年志愿者中选取膝关节内侧移位(medial knee displacement，MKD)组30例和正常对照组30例。应用手持数字测力计测试臀大肌、臀中肌和内收肌的最大等长收缩（maximal voluntary isometric contraction，MVIC）肌力，并以自身体重为基准进行标准化；应用无线表面肌电测试系统检测单腿下蹲过程中臀大肌、臀中肌和髋关节内收肌的表面肌电图，计算均方根振幅（RMS），并以MVIC表面肌电值为基准进行标准化，比较两组间标准化肌力和标准化肌电图RMS的差异。 结果：MKD组和正常组比较，臀大肌、臀中肌和内收肌的标准化MVIC肌力均无明显差异。单腿下蹲时MKD组臀大肌和臀中肌标准化肌电RMS（14.9±5.6和30.8±13.4）均明显低于正常对照组（19.2±6.8和39.4±17.1），内收肌标准化肌电RMS（21.2±14.1）明显高于正常对照组（14.3±8.6），MKD者臀大肌/内收肌和臀中肌/内收肌比值（1.4±0.53和2.7±1.2）明显低于正常对照组（2.3±1.6和4.6±3.7），差异均有显著性意义。 结论：膝关节内侧移位的发生机制可能与臀大肌、臀中肌的激活不足和内收肌的过度激活有关，对膝关节损伤的防治应更加注重髋部肌肉运动控制和协调性的改善。

Abstract:

      Abstract Objective:To investigate the mechanism of medial knee displacement(MKD) and the prevention and therapeutic methods of knee injury through studying the strength and SEMG of hip muscles when in a single leg squat. Method:30 subjects who presented MKD in a single leg squat and 30 normal subjects were selected from the male youth volunteers. A maximal voluntary isometric contraction(MVIC) was recorded for gluteus maximus, gluteus medius and hip adductor by handheld digital dynamometer and normalized to each subject's weight. A wireless surface EMG system was used to record the muscle activity of the hip muscles in a single leg squat(SLS). Mean EMG amplitude during the descent phase of the SLS was normalized to MVIC activation. Result:No significant differences were observed between two groups for any of the normalized MVIC values for the 3 muscle groups. The normalized RMS amplitude of gluteus maximus and gluteus medius of MKD group（14.9±5.6和30.8±13.4） were significantly lower than that of the normal group（19.2±6.8和39.4±17.1）. The normalized RMS amplitude of hip adductor（21.2±14.1）was significantly higher than that of the normal group（14.3±8.6）. Significant differences were observed between two groups for the gluteus medius/hip adductor ratio and the gluteus maximus/hip adductor ratio. Conclusion:The medial knee displacement may be associated with a more activation of hip adductor and less activation of gluteus maximus and gluteus medius. Altered hip adductor and gluteal musculature coactivation may contribute to medial knee displacement during SLS. Motor control of hip muscles should be more emphasized in the prevention and treatment of knee injury.