The Gait Analysis Laboratory, Dept. of Orthopaedic Surgery, Hvidovre University Hospital, Kettegaard Allé 30, DK-2650 Hvidovre, Denmark.
J Electromyogr Kinesiol. 2011 Apr;21(2):371-5. doi: 10.1016/j.jelekin.2010.10.008. Epub 2010 Dec 15.
It is well established that female athletes are at increased risk for sustaining ACL injuries in sports, where sudden changes of direction are a frequent movement pattern. The underlying neuromuscular mechanisms related to the elevated ACL injury rate in female athletes has yet to be fully investigated. This cross-sectional study aimed to examine gender differences in neuromuscular pre-activity during a maneuver that mimics a movement associated with the incidence of ACL injuries. Twenty-four team handball players (12 male and 12 female) with no history of ACL injury were tested for EMG pre-activity of vastus lateralis, vastus medialis, semitendinosus, and biceps femoris during a side-cutting maneuver. Mean EMG amplitude 50ms prior to toe down was normalized to maximal EMG obtained during maximal isometric contraction. The results showed that females had significantly lower hamstring EMG pre-activity 50ms prior to toe-down than males (P<0.01). No gender difference was present in quadriceps EMG pre-activity during side-cutting. Lower hamstring activation prior to toe-down may result in lower hamstring contraction force during the initial part of the ground contact, and thus lesser knee joint stability compared to males. Specific training should be employed to alter the neuromuscular coordination towards a more stabilizing motor pattern.
众所周知，女性运动员在体育运动中更容易发生 ACL 损伤，而突然改变方向是常见的运动模式。女性运动员 ACL 损伤率升高的潜在神经肌肉机制尚未得到充分研究。本横断面研究旨在探讨在模仿与 ACL 损伤发生相关的运动的动作中，神经肌肉预激活的性别差异。24 名无 ACL 损伤史的团队手球运动员（男 12 名，女 12 名）接受了侧切动作中股外侧肌、股内侧肌、半腱肌和股二头肌的肌电图预激活测试。在足趾着地前 50ms 的平均肌电图幅度被归一化为最大等长收缩时获得的最大肌电图。结果表明，女性在足趾着地前 50ms 的腘绳肌肌电图预激活明显低于男性（P<0.01）。在侧切过程中，股四头肌的肌电图预激活没有性别差异。足趾着地前的腘绳肌激活程度较低，可能导致在初始地面接触阶段的腘绳肌收缩力较低，从而与男性相比膝关节稳定性较差。应采用特定的训练来改变神经肌肉协调性，以形成更稳定的运动模式。
