OpenSim 4.0 plugin to estimate contact forces based on the work of D. Krüger and S. Wartzack. This plugin was re-implemented by me based on the initial version provided by D. Krüger, which did not work anymore for newer OpenSim versions. It can be used to estimate contact reaction forces within OpenSim's static optimization, assuming a point-on-plane model considering static and kinetic friction according to Coulomb's law. This approach was applied by be in order to estimate ground reaction forces during human gait.

D. Krüger and S. Wartzack, “A contact model to simulate human–artifact interaction based on force optimization: implementation and application to the analysis of a training machine,” Computer Methods in Biomechanics and Biomedical Engineering, pp. 1–10, Oct. 2017. DOI: 10.1080/10255842.2017.1393804

https://www.researchgate.net/publication/320734626_A_contact_model_to_simulate_human-artifact_interaction_based_on_force_optimization_implementation_and_application_to_the_analysis_of_a_training_machine

https://simtk.org/projects/statopt-contact

To install and use the plugin, please refer to https://simtk-confluence.stanford.edu:8443/display/OpenSim/Using+Plugins and the provided documentation file.

• OpenSim >= 4.0