This paper presents a novel fiber-based muscle model for the forward dynamics of the musculoskeletal system. While bones are represented by rigid bodies, the muscles are taken into account by means of one-dimensional cables that obey the laws of continuum mechanics. In contrast to standard force elements such as the Hill-type muscle model, this approach is close to the real physiology and also avoids the issue of wobbling masses. On the other hand, the computational cost is rather low in comparison with full 3D continuum mechanics simulations. The cable model includes sliding contact between individual fibers as well as between fibers and bones. For the discretization, cubic finite elements are employed in combination with implicit time stepping. Several validation studies and the simulation of a motion scenario for the upper limb demonstrate the potential of the fiber-based approach.

本文提出了一种新颖的基于纤维的肌肉模型，用于肌肉骨骼系统的前向动力学。骨骼以刚体表示，而肌肉则通过遵循连续力学定律的一维电缆来考虑。与诸如希尔型肌肉模型之类的标准受力元素相比，这种方法与真实的生理学非常接近，并且还避免了晃动的问题。另一方面，与完整的3D连续体力学仿真相比，计算成本相当低。电缆模型包括各个纤维之间以及纤维与骨骼之间的滑动接触。对于离散化，立方有限元与隐式时间步长结合使用。