The model used for all studies involved in this project is available for download.

Please cite:
Pelegrinelli ARM, Catelli DS, Kowalski E, Lamontagne M, Moura FA. Comparing three generic musculoskeletal models to estimate the tibiofemoral reaction forces during gait and sit-to-stand tasks, Medical Engineering & Physics, 2023,104074.
ISSN 1350-4533
https://doi.org/10.1016/j.medengphy.2023.104074.

Knee osteoarthritis has a prevalence increasing around the world, and tibiofemoral contact forces are related to the onset and progression of osteoarthritis. Using OpenSim, it is possible to estimate the tibiofemoral contact forces and muscle forces during different functional tasks. Different musculoskeletal models have been developed to improve the accuracy of contact force estimation.
This project aims to investigate the difference in tibiofemoral contact forces between healthy individuals and knee osteoarthritis patients. Recently, some researchers improved the capacity of musculoskeletal models to predict contact forces. Rajagopal et al. (2016), using cadaveric and MRI data, improved the geometry of the lower limb model, significantly improving the accuracy of muscle force prediction. This model is the most commonly used to evaluate lower limb forces. More recently, Bedo et al. (2020) combined the Catelli et al. (2019) model, which accounts for movements with high hip and knee flexion, with a compartment tibiofemoral force proposed by Lerner et al. (2015) to estimate compartmental forces during different tasks. Finally, Uhlrich et al. (2022) improved the Rajagopal model by adjusting some muscle parameters to enhance the accuracy of muscle forces.
For the general purpose of this project, which is to analyze the differences between healthy individuals and knee osteoarthritis patients, a combined model using the Bedo model, Rajagopal model, and Ulrich model was tested. This combined model was evaluated using the CAMS Knee Dataset to assess its capacity to estimate tibiofemoral forces compared to measurements with instrumented knee prostheses. The analyses were performed for gait, sit-to-stand, and stand-to-sit tasks.
Other two studies were developed comparing the tibiofemoral contact forces and muscle forces during gait and sitting down and standing up tasks in healthy and knee osteoarthritis patients. Lastly, one more study was developed to investigate the performance of different machine learning models to predict the tibiofemoral contact forces during the gait using only the kinematic and joint moments.

References about the models included in the new adapted model:

Bedo B., Catelli, D.S., Lamontagne, M., Santiago, P.R.P., 2020. A custom musculoskeletal model for estimation of medial and lateral tibiofemoral contact forces during tasks with high knee and hip flexions. Computer methods in biomechanics and biomedical engineering 23, 658-663.
Catelli, D.S., Wesseling, M., Jonkers, I., Lamontagne, M., 2019. A musculoskeletal model customized for squatting task. Computer methods in biomechanics and biomedical engineering 22, 21-24.
Lerner, Z.F., DeMers, M.S., Delp, S.L., Browning, R.C., 2015. How tibiofemoral alignment and contact locations affect predictions of medial and lateral tibiofemoral contact forces. Journal of Biomechanics 48, 644-650.
Rajagopal, A., Dembia, C.L., DeMers, M.S., Delp, D.D., Hicks, J.L., Delp, S.L., 2016. Full-Body Musculoskeletal Model for Muscle-Driven Simulation of Human Gait. IEEE Transactions on Biomedical Engineering 63, 2068-2079.
Uhlrich, S.D., Jackson, R.W., Seth, A., Kolesar, J.A., Delp, S.L., 2022. Muscle coordination retraining inspired by musculoskeletal simulations reduces knee contact force. Scientific reports 12, 9842.