In musculoskeletal models knowledge of changing muscle lengths and moment arms during motion is crucial to calculate accurately joint load, muscle's force and muscle's energy consumption. Especially in complex 3D joint motions, moment arms are not available in the literature. In this study a framework is presented for calculating the athlete's individual muscle lengths during sports by means of motion analysis. Bones were simulated by use of anatomical data and presented as triangulated surface meshes. Muscle length was calculated as the shortest path from origin to insertion by means of the dijkstra algorithm. The validity of the calculated muscle lengths was tested for a simple elbow flexion motion on existing data in the literature. Therefore this approach might be confident to calculate valid individual muscle length in complex joint positions. The algorithm worked well for muscles running directly beyond the bones, but no underlying muscles or tissues can be considered. Therefore in the next step, muscles should be modelled as volumetric tetrahedral meshes to simulate muscles' deformations during motion.     «

In musculoskeletal models knowledge of changing muscle lengths and moment arms during motion is crucial to calculate accurately joint load, muscle's force and muscle's energy consumption. Especially in complex 3D joint motions, moment arms are not available in the literature. In this study a framework is presented for calculating the athlete's individual muscle lengths during sports by means of motion analysis. Bones were simulated by use of anatomical data and presented as triangulated surface...     »