Sensitivity of the anthropometrical and geometrical parameters of the bones and muscles on a musculoskeletal model of the lower limbs.

Modelling is necessary to understand and evaluate the musculoskeletal system of the human body. Most of the developed models used anthropometrical and geometrical parameters of the bones and muscles from the literature. The aim of the present work was to study the sensitivity of anthropometrical (segment mass) and geometrical (physiologic cross-sectional area of the muscle) parameters on musculoskeletal model of the lower limbs for simulation of the gait. An inverse dynamic analysis was performed to activate the joints and muscles. Then a direct dynamic analysis was carried out with active joints and muscles. The influences of these parameters on the kinematics and kinetics simulation results were reported. The obtained results show an influence of these parameters on the simulation results (maximal relative error varying from 2 to 75%). These results suggest subject specific parameters to be considered.