This video shows musculoskeletal, dynamic simulations of the running gait cycle for at four running speeds: 2.0 m/s, 3.0 m/s, 4.0 m/s, and 5.0 m/s. These are simulations of a complete running gait cycle for a representative subject at each speed. Each gait cycle starts at right foot strike and ends at the subsequent right foot strike. Muscle color indicates simulated activation level from no activation (dark blue) to full activation (bright red). The simulations are shown in real time, half speed, and with a normalized gait cycle. In particular, these videos highlight some key differences that occur with increased running speed, including a larger range of motion in the lower extremity joints, a larger step length, a short stride time, and increased muscle activation.
These simulations were created as part of a study to examine how muscle forces and arm swing affect dynamics of the body at different running speeds. Specifically, we sought to determine how muscle forces contribute to mass center accelerations during the stance phase of running, and how the arms act to counterbalance motion of the legs at different running speeds. To enable others to reproduce the results of our simulations and extend this work, all of the software, models, and data used to create and analyze the simulations are freely available. We provide open-access to the 120 subject-specific simulations developed for this study at simtk.org/home/nmbl_running for analysis in OpenSim.
If you use this video or the accompanying simulations or data, please cite as "Hamner, S.R., Delp, S.L., Muscle contributions to fore-aft and vertical body mass center accelerations over a range of running speeds. Journal of Biomechanics (2012), dx.doi.org/10.1016/j.jbiomech.2012.11.024".