Numerical simulations are playing an increasingly important role in solving complex engineering problems, and have the potential to revolutionize medical decision making and treatment design. Musculoskeletal diseases cost the United States economy an estimated $849 billion a year (equal to 7.7% of the gross domestic product) and place great demands on the healthcare system. This research area could greatly benefit from computational tools that offer greater understanding of neuromuscular biomechanics, and predictive capabilities for optimal surgical and rehabilitation treatment planning.

The MATLAB®/Simulink® package is the world’s leading mathematical computing software for engineers and scientists in industry, government, and education. Although Simulink® extends MATLAB® with a graphical environment for rapid design, control, and simulation of complex dynamic systems, this powerful package has limited resources for simulations of neuromusculoskeletal systems. On the contrary, OpenSim is a popular open-source platform for modeling, simulating, and analyzing neuromusculoskeletal systems, but it is lacks the robust design and control tools of Simulink®.

This project is an interface between OpenSim and MATLAB®/Simulink® that combines relevant strengths (e.g., neuromusculoskeletal dynamics, rapid model-based design, control systems, and numerical simulation) of each individual software package. The foundation of this interface is a MATLAB® S-function (system-function) based on an OpenSim model as a Simulink® block written in C++ and compiled as a MEX-file using the MATLAB® mex utility.