Ilan Eskinazi and Benjamin J. Fregly, University of Florida, USA, Volume 63, Issue 2, Page: 269-277
Incorporation of elastic joint contact models into simulations of human movement could facilitate studying the interactions between muscles, ligaments, and bones. Unfortunately, elastic joint contact models are often too expensive computationally to be used within iterative simulation or optimization frameworks. This limitation can be overcome by using fast and accurate surrogate contact models that fit or interpolate input-output data sampled from existing elastic contact models. However, construction of surrogate contact models remains an arduous task. We have developed a freely-available open-source program called Surrogate Contact Modeling Toolbox (SCMT) to facilitate the design, construction, and testing of surrogate joint contact models. SCMT interacts with the third party software FEBio to perform elastic contact analyses of finite element models and uses Matlab to train neural networks that fit the resulting input-output contact data. SCMT features sample point generation for multiple domains, automated sampling, data filtering, and surrogate model training and testing. SCMT not only facilitates the creation of computationally fast surrogate contact models but also serves as a bridge between FEBio and OpenSim musculoskeletal modeling software. Two example applications are provided. The first demonstrates creation of surrogate contact models of artificial tibiofemoral and patellofemoral joints and evaluates their computational speed and accuracy, while the second demonstrates the use of surrogate contact models in a forward dynamic simulation of an open-chain leg extension-flexion motion. Our hope is that use of SCMT by the musculoskeletal modeling community will lead to realistic simulations of joint kinematics, more accurate estimation of muscle and joint contact forces, and predictive simulations of rehabilitation and surgical interventions.
Research website: http://web.mae.ufl.edu/~fregly/
Keywords: Biomechanics, joint contact, musculoskeletal modeling, surrogate modeling, toolbox.