The National Institute of Health (NIH) supported center for physics-based Simulation of Biological Structures (Simbios) at Stanford University has developed OpenSim, a free software tool that can model and simulate movement of humans and animals.
OpenSim calculates forces generated by different muscles as they are activated and deactivated at different times when a human or animal walks or runs. The software can be used to help doctors model a patient’s muscles, which then could be used in corrective surgery for cerebral palsy, osteoarthritis, or spinal injuries.
OpenSim was an entrant to the NIH Common Fund Video Competition. Watch their video submission and check out their YouTube channel for more information.