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This project contains an OpenSIM model file that includes a torso segment in addition to the lower extremity. The model contains 23 degrees of freedom and 92 muscle-tendon actuators. The joint between the torso and the pelvis is represented by a ball-and-socket joint. In order to respect the time and effort put in by the original developers please carefully read accompanying publications and cite appropriate references in future work. The links to the left contain all the files (Downloads) and documentation (Documents) related to the model.

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Please cite the following paper:
- Delp, S.L., Loan, J.P., Hoy, M.G., Zajac, F.E., Topp E.L., Rosen, J.M.: An interactive graphics-based model of the lower extremity to study orthopaedic surgical procedures, IEEE Transactions on Biomedical Engineering, vol. 37, pp. 757-767, 1990.

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About the model:
The lower-extremity portion of the model was originally developed by Scott Delp to examine how surgical changes in musculoskeletal geometry and muscle architecture affect muscle force and joint motion. With the addition of the torso segment this model has 23 degrees of freedom and 92 muscle actuators. The model is about 1.8m tall and has the strength of a young, adult male. Muscle lines of action are based on their anatomical relationships to three-dimensional surface representations of bones. A model for each actuator was formulated to compute its isometric force-length relation. The kinematics of the lower extremity is specified by modeling the lumbar, hip, knee, ankle, subtalar, and metatarsophalangeal joints.

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