Shultz S J, Perrin D H, Adams J M, Arnold B L, Gansneder B M, Granata K P
University of Virginia, 203 Memorial Gymnasium, 22903, Charlottesville, VA 22903, USA.
J Electromyogr Kinesiol. 2000 Jun;10(3):159-70. doi: 10.1016/s1050-6411(00)00002-x.
Previous research indicates that both the extent and timing of muscular activation at the knee can be influenced by muscle activity state, joint angle, weight-bearing status and trunk position. However, little research to date has evaluated protective neuromuscular response times and activation patterns to an imposed perturbation with the knee joint in a functional, weight-bearing stance. Hence, we designed a lower extremity perturbation device to produce a sudden, forward and either internal or external rotation moment of the trunk and femur relative to the weight-bearing tibia. Surface electromyography (EMG) recorded long latency reflex times of the medial and lateral quadriceps, hamstring and gastrocnemius muscles in 64 intercollegiate lacrosse and soccer players in response to both internal and external rotation perturbation. We found the gastrocnemius fired significantly faster that the hamstring, which in turn fired significantly faster than the quadriceps. There was also a significant difference in activation times of the medial and lateral hamstring not found for the quadriceps or gastrocnemius muscles. Our findings confirmed that reactive neuromuscular responses following this functional perturbation differ markedly from those previously reported using seated, partial weight-bearing and/or uni-planar models under relaxed conditions.
先前的研究表明，膝关节处肌肉激活的程度和时机可能会受到肌肉活动状态、关节角度、负重状态和躯干位置的影响。然而，迄今为止，几乎没有研究评估在功能性负重姿势下，膝关节对施加的扰动的保护性神经肌肉反应时间和激活模式。因此，我们设计了一种下肢扰动装置，以产生相对于负重胫骨的躯干和股骨突然的向前以及内旋或外旋力矩。表面肌电图（EMG）记录了64名大学长曲棍球和足球运动员的股内侧肌、股外侧肌、腘绳肌和腓肠肌在对内旋和外旋扰动做出反应时的长潜伏期反射时间。我们发现，腓肠肌的放电速度明显快于腘绳肌，而腘绳肌的放电速度又明显快于股四头肌。内侧和外侧腘绳肌的激活时间也存在显著差异，而股四头肌和腓肠肌未发现这种差异。我们的研究结果证实，这种功能性扰动后的反应性神经肌肉反应与先前在放松条件下使用坐姿、部分负重和/或单平面模型所报告的反应明显不同。
