This is a simplified, single-leg model (leg6dof9musc.osim – 6 degrees of freedom, 9 muscles) that is packaged with the OpenSim distribution. The leg model consists of 7 bodies representing four physiological segments (pelvis, thigh, shank, and foot). The configuration of the system is described by 6 generalized coordinates (pelvis_tilt, pelvis_tx, pelvis_ty, hip_flexion_r, knee_angle_r, and ankle_angle_r). The musculoskeletal forces are generated by 9 muscles (psoas major, gluteus maximus, rectus femoris, vastus intermedius, biceps femoris long head, biceps femoris short head, tibialis anterior, medial gastrocnemius, and soleus).
This simple model is not intended for research.