Analytic analysis of the force sharing among synergistic muscles in one- and two-degree-of-freedom models
Analytic analysis of the force sharing among synergistic muscles in one- and two-degree-of-freedom models
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DOI：
10.1016/s0021-9290(00)00108-1
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发表时间：
2000-11-01
影响因子：
2.4
通讯作者：
Herzog, W
中科院分区：
文献类型：
--
作者：
Binding, P;Jinha, A;Herzog, W
在计算个体肌肉力量的理论模型中，已经使用了特定成本函数的数学优化。对单个肌肉力量和各个肌肉之间的力量分配的测量显示出一种依赖于强度的非线性行为。已有研究表明，猫的腓肠肌、足底肌和比目鱼肌之间的力分享呈现出明显的环路，这些环路根据运动的强度而系统地改变方向。这项研究的目的是证明静态的、非线性的优化是否可以内在地预测运动肌肉之间的力分享环。采用两种常用的优化算法和两种肌肉骨骼模型，利用猫步进周期的关节力矩数据，计算了猫踝足底三个屈肌(腓肠肌、足底肌群和比目鱼肌)的受力情况。这两个肌肉骨骼模型包括一个只考虑踝关节的单自由度模型和一个包括踝关节和膝关节的两自由度模型。本研究的主要结论是，单自由度模型的解不能保证力共享回路，但两自由度模型预测的力共享回路与肌肉和肌肉骨骼几何的输入参数的特定值无关。预测的力分享环被发现是由力矩-力矩图中的膝盖和脚踝力矩形成的环的直接结果。(C)2000爱思唯尔科学有限公司。保留所有权利。
Mathematical optimization of specific cost functions has been used in theoretical models to calculate individual muscle forces. Measurements of individual muscle forces and force sharing among individual muscles show an intensity-dependent, non-linear behavior. It has been demonstrated that the force sharing between the cat Gastrocnemius, Plantaris and Soleus shows distinct loops that change orientation systematically depending on the intensity of the movement. The purpose of this study was to prove whether or not static, non-linear optimization could inherently predict force sharing loops between agonistic muscles. Using joint moment data from a step cycle of cat locomotion, the forces in three cat ankle plantar flexors (Gastrocnemius, Plantaris and Soleus) were calculated using two popular optimization algorithms and two musculo-skeletal models. The two musculo-skeletal models included a one-degree-of-freedom model that considered the ankle joint exclusively and a two-degree-of-freedom model that included the ankle and the knee joint. The main conclusion of this study was that solutions of the one-degree-of-freedom model do not guarantee force-sharing loops, but the two-degree-of-freedom model predicts force-sharing loops independent of the specific values of the input parameters for the muscles and the musculo-skeletal geometry. The predicted force-sharing loops were found to be a direct result of the loops formed by the knee and ankle moments in a moment-moment graph. (C) 2000 Elsevier Science Ltd. All rights reserved.