Tamura Youjiro, Saito Masami, Ito Akira
Department of Physics, Suzuka National College of Technology, Shiroko-cho, Suzuka 510-0294, Japan.
J Biomech. 2009 Feb 9;42(3):400-3. doi: 10.1016/j.jbiomech.2008.11.018. Epub 2009 Jan 14.
We previously proposed a systematic motor model for muscle with two parallel Maxwell elements and a force generator P. The motor model showed the non-linear behavior of a muscle, such as the force-velocity relation and the force depression and enhancement, by using weight functions. Our newly proposed muscle model is based on the molecular mechanism of myosin cross-bridges. We assume that each parallel Maxwell element represents the mechanical properties of weak and strong binding of the myosin head to actin. Furthermore, we introduce a controller to simulate the excitation-contraction coupling of the muscle. The new muscle model satisfies all the properties obtained in our previous model and reduces the wasted energy of the viscous component to less than 5% of the total energy. The controller enables us to simulate contractions of slow and fast twitch muscles, which are driven by an artificial action potential or a processing electromyography signal despite their same mechanical components. The maximum velocities are calculated to be 3.4L(0)m/s for the fast twitch muscle model and 2.5L(0)m/s for the slow twitch muscle model, where L(0) is the initial length of the muscle model.
我们之前提出了一种针对肌肉的系统运动模型，该模型包含两个并联的麦克斯韦元件和一个力发生器P。通过使用权重函数，该运动模型展现了肌肉的非线性行为，如力-速度关系以及力的衰减和增强。我们新提出的肌肉模型基于肌球蛋白横桥的分子机制。我们假设每个并联的麦克斯韦元件代表肌球蛋白头部与肌动蛋白弱结合和强结合的力学特性。此外，我们引入了一个控制器来模拟肌肉的兴奋-收缩偶联。新的肌肉模型满足了我们之前模型所具备的所有特性，并将粘性成分的能量损耗降低至总能量的5%以下。该控制器使我们能够模拟慢肌和快肌的收缩，尽管它们具有相同的机械组件，但可由人工动作电位或处理后的肌电图信号驱动。计算得出，快肌模型的最大速度为3.4L(0)m/s，慢肌模型的最大速度为2.5L(0)m/s，其中L(0)是肌肉模型的初始长度。
