Myer Gregory D, Ford Kevin R, Hewett Timothy E
Division of Sports Medicine and Division of Molecular Cardiovascular Biology, Sports Medicine Biodynamics Center, Human Performance Laboratory, Cincinnati Children's Hospital Research Foundation, Cincinnati OH 45229, USA.
J Electromyogr Kinesiol. 2005 Apr;15(2):181-9. doi: 10.1016/j.jelekin.2004.08.006.
While the increased incidence of serious knee injuries in female athletes is well established, the underlying neuromuscular mechanisms related to the elevated ACL injury rate has yet to be delineated. Video analysis of ACL injury during competitive sports play indicates a common body position associated with non-contact ACL injury; the tibia is externally rotated, the knee is close to full extension, the foot is planted and as the limb is decelerated it collapses into valgus. The purpose of the current prospective study was to evaluate gender differences in quadriceps muscle activation strategies when performing a physically challenging, but reproducible maneuver that mimics the high ACL injury risk position (in the absence of high velocity and high loads). Twenty physically active college-aged subjects (10 male and 10 female) performed multiple sets of the prescribed exercise. EMG recordings were employed to measure the ratio of activation between the medial and lateral quadriceps during the 4, 8, 12, 16, and 20th sets of exercise. Females demonstrated decreased RMS medial-to-lateral quadriceps ratios compared to males (F(1,18)=5.88, p=0.026). There was no main effect of set number on RMS quadriceps ratio (p>0.05). The results of this study suggest that females utilize neuromuscular activation strategies which may contribute to "dynamic valgus" and ACL rupture when performing high-risk maneuvers.
虽然女性运动员严重膝伤的发病率增加已得到充分证实，但与前交叉韧带（ACL）损伤率升高相关的潜在神经肌肉机制尚未明确。对竞技运动中ACL损伤的视频分析表明，非接触性ACL损伤存在一个常见的身体姿势；胫骨外旋，膝关节接近完全伸展，足部着地，并且当肢体减速时会内翻塌陷。本前瞻性研究的目的是评估在进行一项具有身体挑战性但可重复的动作时，四头肌肌肉激活策略的性别差异，该动作模仿了高ACL损伤风险姿势（在没有高速和高负荷的情况下）。20名身体活跃的大学生（10名男性和10名女性）进行了多组规定的运动。在第4、8、12、16和20组运动期间，采用肌电图记录来测量股内侧肌和股外侧肌之间的激活比例。与男性相比，女性股内侧肌与股外侧肌的均方根（RMS）比例降低（F(1,18)=5.88，p=0.026）。组数对股四头肌RMS比例没有主要影响（p>0.05）。本研究结果表明，女性在进行高风险动作时利用的神经肌肉激活策略可能会导致“动态内翻”和ACL断裂。
