Tamura Youjiro
a Department of Physics , Suzuka National College of Technology , Suzuka , Japan.
Comput Methods Biomech Biomed Engin. 2018 Jan;21(1):75-82. doi: 10.1080/10255842.2018.1424837. Epub 2018 Jan 12.
A muscle model that uses a modified Langevin equation with actomyosin potentials was used to describe the residual force enhancement after active stretching. Considering that the new model uses cross-bridge theory to describe the residual force enhancement, it is different from other models that use passive stretching elements. Residual force enhancement was simulated using a half sarcomere comprising 100 myosin molecules. In this paper, impulse is defined as the integral of an excess force from the steady isometric force over the time interval for which a stretch is applied. The impulse was calculated from the force response due to fast and slow muscle stretches to demonstrate the viscoelastic property of the cross-bridges. A cross-bridge mechanism was proposed as a way to describe the residual force enhancement on the basis of the impulse results with reference to the compliance of the actin filament. It was assumed that the period of the actin potential increased by 0.5% and the amplitude of the potential decreased by 0.5% when the half sarcomere was stretched by 10%. The residual force enhancement after 21.0% sarcomere stretching was 6.9% of the maximum isometric force of the muscle; this value was due to the increase in the number of cross-bridges.
一个使用带有肌动球蛋白电位的修正朗之万方程的肌肉模型被用来描述主动拉伸后的残余力增强。考虑到新模型使用横桥理论来描述残余力增强，它与其他使用被动拉伸元件的模型不同。使用包含100个肌球蛋白分子的半肌节模拟残余力增强。在本文中，冲量被定义为在施加拉伸的时间间隔内，超过稳定等长力的额外力的积分。通过快速和慢速肌肉拉伸产生的力响应来计算冲量，以证明横桥的粘弹性特性。基于冲量结果并参考肌动蛋白丝的顺应性，提出了一种横桥机制来描述残余力增强。假设当半肌节拉伸10%时，肌动蛋白电位的周期增加0.5%，电位幅度降低0.5%。肌节拉伸21.0%后的残余力增强为肌肉最大等长力的6.9%；该值归因于横桥数量的增加。
