Centre de Recherche en Sciences Neurologiques, Faculté de Médecine, Université de Montréal, Montréal, Canada; Centre de recherche, Institut de Réadaptation de Montréal, Montréal, Canada.
J Electromyogr Kinesiol. 1997 Jun;7(2):141-8. doi: 10.1016/s1050-6411(96)00021-1.
The hypothesis that the pattern of muscle activation during a static voluntary effort exerted in different directions is oriented in the direction of the muscle's mechanical action was evaluated. The electromyographical (EMG) activation patterns of five hip muscles (gluteus medius, rectus femoris, tensor fasciae latae, gracilis and semitendinosus) and one knee muscle (vastus lateralis) were characterized in 11 normal subjects during static efforts at the hip joint. Subjects were asked to generate torques (10 and 20 Nm) in 24 directions covering 360 degrees at increments of 15 degrees in the transverse plane of the femur whereas torques at the knee were to be kept at zero. Using vector summation of the rectified EMGs, a mean angular value of muscle activation was calculated for each muscle across subjects. It was observed that the mean angular values of muscles acting at the hip were significantly oriented, whereas the activity of the vastus lateralis was not significantly oriented. In addition, the angular values of activation of the rectus femoris, tensor fasciae latae and semitendinosus muscles were not significantly different from the direction of mechanical action of these respective muscles as determined using a biomechanical model of the hip. However, the angular values of the gluteus medius and gracilis activations were found to be significantly different from their anatomical line of action. The angular values of activation of two muscles (rectus femoris and gluteus medius) were also compared to the mechanical pulling direction of these muscles as determined following electrical stimulation of the recorded muscle regions. The analysis revealed that the angular value of the gluteus medius and rectus femoris during voluntary static efforts at the hip was not significantly different from the direction of mechanical action of these muscles as determined by the electrical stimulation. In general, these results support the hypothesis that the degree of a muscle's activation in one direction is determined as a function of its mechanical action.
评估了在不同方向施加的静态自主用力期间肌肉激活模式是否朝着肌肉机械作用方向定向的假设。在 11 名正常受试者中，在髋关节处进行静态用力时，对 5 个髋关节肌肉（臀中肌、股直肌、阔筋膜张肌、股薄肌和半腱肌）和 1 个膝关节肌肉（股外侧肌）的肌电图（EMG）激活模式进行了特征描述。要求受试者在股骨的横平面上以 15 度的增量产生覆盖 360 度的 24 个方向的扭矩（10 和 20 Nm），而膝关节处的扭矩应保持为零。通过对经整流的 EMG 的矢量求和，计算了每个肌肉在所有受试者中的平均激活角度值。结果发现，作用于髋关节的肌肉的平均角度值明显定向，而股外侧肌的活性则没有明显定向。此外，股直肌、阔筋膜张肌和半腱肌的激活角度值与使用髋关节生物力学模型确定的这些肌肉的机械作用方向没有显著差异。然而，臀中肌和股薄肌的激活角度值被发现与它们的解剖作用线明显不同。还比较了两个肌肉（股直肌和臀中肌）的激活角度值与这些肌肉在记录的肌肉区域电刺激后确定的机械拉动方向。分析表明，在髋关节的自主静态用力期间，臀中肌和股直肌的激活角度值与电刺激确定的这些肌肉的机械作用方向没有显著差异。总的来说，这些结果支持了肌肉在一个方向上的激活程度是由其机械作用决定的假设。
