[Estimation of muscle forces during natural movement of man on the basis of minimization of various functions].

Forces exerted by 11 muscles of lower extremities of a man in squat jump were determined using 4-link planar muscular-skeletal model. The research project was performed in two stages: 1) kinematic data were used for the calculation of control moments in joints, 2) determination of muscle forces as a result of minimization procedure of 5 objective functions with constraints to forces. The forces found were compared with corresponding EMG-activity of muscles. The highest correlation with EMG parameters was shown by the minimized sum of absolute powers of all muscles.