Coupling finite element and huxley models in multiscale muscle modeling

In this paper we present a novel approach in multi-scale muscle modeling based on finite element method and Huxley crossbridge kinetics model. In order to determine the mechanical response of a muscle, we implement basic mechanical principles of motion of deformable bodies using finite element method. Constitutive properties of muscle are defined by the number of molecular interconnections between the myosin and actin filaments. To account for these effects, we used Huxley's micro model based on sliding filament theory to calculate muscle active forces and instantaneous stiffnesses in FE integration points. In order to run these computationally expensive simulations we have also developed a special parallelization strategy which gives speedup of two orders of magnitude. Results obtained using presented multi-scale model are compared to those obtained by Hill's phenomenological model.