A 12 degrees of freedom musculoskeletal model combined with a muscle force driven fibril-reinforced poroviscoelastic finite element model

We present a novel multiscale modelling approach for investigating knee joint tissue mechanics during dynamic activities. Based on a musculoskeletal model with 12 degrees of freedom (DOF) knee joint (tibiofemoral and patellofemoral joints), muscle forces, knee joint contact forces and moments, and the knee flexion angle during gait were estimated and used as inputs to a 12 DOFs muscle force driven fibril-reinforced poroviscoelastic finite element model to estimate cartilage mechanics. The resulting joint contact forces, maximum principal stresses and fibril strains of tibial cartilage were compared to outputs calculated when using a musculoskeletal model with a 1 DOF knee joint. Although the maximum joint contact force was increased at ~25% of the stance phase, the maximum tissue stress was not increased when using the novel model.