Department of Mechanical and Biomedical Engineering, Boise State University, Boise, ID 83725, USA.
J Biomech. 2010 Oct 19;43(14):2780-4. doi: 10.1016/j.jbiomech.2010.06.011. Epub 2010 Jul 23.
Muscles are significant contributors to the high joint forces developed in the knee during human walking. Not only do muscles contribute to the knee joint forces by acting to compress the joint, but they also develop joint forces indirectly through their contributions to the ground reaction forces via dynamic coupling. Thus, muscles can have significant contributions to forces at joints they do not span. However, few studies have investigated how the major lower-limb muscles contribute to the knee joint contact forces during walking. The goal of this study was to use a muscle-actuated forward dynamics simulation of walking to identify how individual muscles contribute to the axial tibio-femoral joint force. The simulation results showed that the vastii muscles are the primary contributors to the axial joint force in early stance while the gastrocnemius is the primary contributor in late stance. The tibio-femoral joint force generated by these muscles was at times greater than the muscle forces themselves. Muscles that do not cross the knee joint (e.g., the gluteus maximus and soleus) also have significant contributions to the tibio-femoral joint force through their contributions to the ground reaction forces. Further, small changes in walking kinematics (e.g., knee flexion angle) can have a significant effect on the magnitude of the knee joint forces. Thus, altering walking mechanics and muscle coordination patterns to utilize muscle groups that perform the same biomechanical function, yet contribute less to the knee joint forces may be an effective way to reduce knee joint loading during walking.
肌肉在人类行走过程中对膝关节产生的高关节力有重要贡献。肌肉不仅通过压缩关节来作用于膝关节力，而且还通过其对地面反作用力的动态耦合来间接产生关节力。因此，肌肉可以对其不跨越的关节产生显著的力。然而，很少有研究调查主要的下肢肌肉在行走过程中如何对膝关节接触力做出贡献。本研究的目的是使用肌肉驱动的步行正向动力学模拟来确定单个肌肉如何对轴向胫股关节力做出贡献。模拟结果表明，在早期站立阶段，股四头肌是轴向关节力的主要贡献者，而在后期站立阶段，腓肠肌是主要贡献者。这些肌肉产生的胫股关节力有时大于肌肉本身的力。不跨越膝关节的肌肉（如臀大肌和比目鱼肌）也通过对地面反作用力的贡献对胫股关节力有显著贡献。此外，行走运动学的微小变化（例如，膝关节弯曲角度）可能会对膝关节力的大小产生重大影响。因此，改变步行力学和肌肉协调模式，利用执行相同生物力学功能但对膝关节力贡献较小的肌肉群，可能是减少步行时膝关节负荷的有效方法。
