Predicting Moment Arms in Diarthroidal Joints - 3D Computer Simulation Capability and Muscle-Tendon Model Validation

Interactive 3D simulation of musculoskeletal kinematics is used to predict the instantaneous moment arms of muscles acting about joints. Experimental studies were completed to verify the moment arms of muscles in the finger joints and at the knee. For other joints, predictions were compared with studies from the literature. Both methods provided for iterative improvement of the underlying 3D models of muscle tendon paths. Experimental results confirm that muscle-tendon moment arms vary throughout each joint´s range-of-motion; most muscles have more than one function (affect more than one degree-of-freedom); and that computer simulation models can be improved through simple parametric changes in cubic B-spline models of muscle-tendon paths