Lloyd D G, Buchanan T S
Department of Human Movement and Exercise Science, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Crawley, Australia.
J Biomech. 2001 Oct;34(10):1257-67. doi: 10.1016/s0021-9290(01)00095-1.
In this paper we studied how subjects activate their muscles in response to static varus and valgus loads at the knee. The muscles' contributions to the external moments were estimated using an EMG driven biomechanical model of the knee. The individual muscle activation and loading patterns were examined to identify the strategies that the nervous system uses to support varus and valgus knee moments. It was found that the (1) co-contraction of the hamstrings and quadriceps, and (2) activation of the gracilis and tensor fascia lata increased with the increasing magnitude of the varus and valgus moments. These 2 activation patterns provided positive support of valgus and varus loads at the knee The sartorius appears to be activated to provide positive support of valgus loads at the knee, whereas during varus moments this muscle increases the varus load on the knee, i.e. provides negative support. Generally, the hamstrings and quadriceps co-contraction contributed to most of the muscular support of the varus and valgus moments. In addition, co-contraction supported 11-14% of the external moment in pure varus and pure valgus respectively. It appears that there are activation strategies with the specific purpose to support varus and valgus moments, albeit small, which suggest dual goals of the neuromotor system during the support of varus and valgus moments.
在本文中，我们研究了受试者如何响应膝关节的静态内翻和外翻负荷来激活其肌肉。使用肌电图驱动的膝关节生物力学模型估计肌肉对外部力矩的贡献。检查个体肌肉的激活和负荷模式，以确定神经系统用于支持膝关节内翻和外翻力矩的策略。研究发现：（1）随着内翻和外翻力矩大小的增加，腘绳肌和股四头肌的共同收缩以及（2）股薄肌和阔筋膜张肌的激活增加。这两种激活模式为膝关节的外翻和内翻负荷提供了正向支持。缝匠肌似乎被激活以提供膝关节外翻负荷的正向支持，而在内翻力矩期间，该肌肉会增加膝关节的内翻负荷，即提供负向支持。一般来说，腘绳肌和股四头肌的共同收缩对大部分内翻和外翻力矩的肌肉支持起作用。此外，共同收缩分别在单纯内翻和单纯外翻时支持11%-14%的外部力矩。似乎存在具有特定目的来支持内翻和外翻力矩的激活策略，尽管作用较小，这表明在支持内翻和外翻力矩期间神经运动系统具有双重目标。
