Estimation of anthropometrical and inertial body parameters using double integration of residual torques and forces during squat jump

The inertial (IP) and anthropometrical (AP) parameters of human body are mostly estimated from coefficients issue from cadaver measurements. These parameters could involve errors in the calculation of joint torques during explosive movements. The purpose of this study was to optimize the IP and AP in order to minimize the residual torque and force during squat jumping. Three methods of determination have been presented: method A: optimizing AP and IP of each body part, method B: optimizing trunk AP and IP, assuming that the AP and IP of the lower limbs were known, method C: using Winter AP and IP. For each method, the value (degree 0), the integral (degree 1) and the double integral (degree 2) of the residual moment were also used. The method B with degree 2 was the most accurate to determine trunk AP and IP by minimizing of the residual force and torque, by providing a linear least squares system. Instead of minimizing the residual force and torque, by classical way, the double integral of the latter provided more accurate results.