Force enhancement and force depression in a modified muscle model used for activation prediction

Authors: Kosterina, N.K., Wang, R.W., Eriksson,  , Gutierrez-Farewik, E.M.
Document Type: Article
Pubstate: Submitted
Year: 2012


This article presents a skeletal muscle model force for modification applied to dynamic simulations of musculoskeletal system motion. Force depression and force enhancement induced by active muscle shortening and lengthening, respectively, represent muscle history effects. A muscle model depending on the preceding contractile events together with the current parameters was developed for OpenSim software, and applied in simulations of standing heel-raise and squat movements. Muscle activations were computed using joint kinematics and ground reaction forces recorded from the motion capture of seven individuals. In the muscle-actuated simulations, a modification was applied to the computed activation, and was compared to the measured electromyography data. For the studied movements, the history gives a small but visible effect to the muscular force trace. The muscle model modification improves the existing muscle models and gives more accurate description of underlying forces in musculoskeletal system movement simulation.