Musculoskeletal Models

Just as interactive graphics have enhanced engineering analysis and design, we have found that graphics-based musculoskeletal models are effective tools for visualizing human movement, analyzing the functional capacity of muscles, and designing improved surgical procedures. We have created computer models of many different musculoskeletal structures. Researchers from many other labs have also developed models in OpenSim and SIMM.

OpenSim Models

	Gait 2392 Gait 2392 Model Model A three-dimensional, 23 degree-of-freedom computer model of the human musculoskeletal system. The model features lower extremity joint definitions adopted from Delp et al. (1990), low back joint and anthropometry adopted from Anderson and Pandy et al. (1999), and a planar knee model adopted from Yamaguchi and Zajac etal. (1989). The model features 92 musculotendon actuators to represent 76 muscles in the lower extremities and torso. This model has been used in dynamic simulations of normal and pathological walking and other motions.

	Gait 2354 Model A three-dimensional, 23 degree-of-freedom computer model of the human musculoskeletal system. This model is a simplified version of the Gait 2392 model. It features lower extremity joint definitions adopted from Delp et al. (1990), low back joint and anthropometry adopted from Anderson and Pandy et al. (1999), and a planar knee model adopted from Yamaguchi and Zajac etal. (1989), and contains 54 musculotendon actuators to represent 46 muscles in the lower extremities and torso. This model is typically used for educational and demonstration purposes and other cases were faster simulation times are desired.

/wiki/spaces/OpenSim24/pages/54002403	/wiki/spaces/OpenSim24/pages/54002403 Full-body OpenSim model used by Samuel Hamner to create a muscle-actuated simulation of running. It is a modified and expanded version of the Gait 2392 model. The lower-extremity contains the muscles from the Delp (1990) model and the upper-extermity has idealized torque actuators at each degree of freedom (no muscles).

OpenSim Exercise: Evaluate Ankle Inversion Injury Risk During a Drop Landing v3.0	/wiki/spaces/OpenSim24/pages/54002557 A three-dimension, 23-degree-of-freedom musculoskeletal model for simulating drop landings with an AFO. The model is adapted from the Gait 2354 model, with a torso, pelvis, and two legs comprised of 54 muscle-tendon actuators. Attached to the feet are contact spheres that produce forces against the floor. The floor is comprised of a contact plane and four degrees of freedom which can be used to rotate and lower the contact plane relative to the skeleton before simulating a drop. The AFO has a leg cuff and foot plate, connected by a linear bushing.

OpenSim Exercise: Evaluate Ankle Inversion Injury Risk During a Drop Landing v3.0	/wiki/spaces/OpenSim24/pages/54002557 This model is an extension of the DropLanding model above, with an added backpack. This model and the previous model could also be adapted to study walking, running or other motions by disabling or removing the platform and reflex controller.

	Arnold Lower Extremity Model Model of the lower limb based on experimental measurements of muscle architecture in 21 cadavers. The model provides accurate representations of muscle moment arms and force generation capacities and allows detailed examination of the moment generation capacities of muscles about the ankle, knee, and hip. We are currently adapting this model for use with dynamic simulations

SIMM Models

	Upper Extremity Model Fifteen degree-of-freedom model of the human upper extremity that has the strength of a young, adult male and includes the lines of action and parameters of fifty muscle-tendon actuators. The model includes the kinematics of the shoulder, elbow, forearm, wrist, thumb, and forefinger.

	Lower Extremity Model Seven degree-of-freedom model of the human lower extremity that has the strength of a young, adult male and includes the lines of action and parameters of forty-three muscles. The model includes the kinematics of the hip, knee, ankle, subtalar, and proximal metatarsal joints.

	Deformable Lower Extremity Model Four degree-of-freedom model of the human lower extremity with a "deformable" femur that characterizes the geometry of the pelvis, femur, and proximal tibia, the kinematics of the hip and tibiofemoral joints, and the paths of the medial hamstrings, iliopsoas, and adductor muscles for an average-sized adult male.

	MR-Based Lower Extremity Models Four degree-of-freedom models of three lower extremity cadaveric specimens and four subjects with cerebral palsy that were created from MR images. The models characterize the geometry of the pelvis, femur, and proximal tibia, the kinematics of the hip and tibiofemoral joints, and the paths of the hamstrings, iliopsoas, and adductor muscles.

	Human Neck Model Three degree-of-freedom model of the human neck. The model characterizes the moment arms, force- and moment-generating capacities of nineteen muscles over physiological ranges of neck flexion, extension, axial rotation and lateral bending.

	Cat Neck Model Model of the cat neck that characterizes the sagittal-plane kinematics at the skull-C1, and between each of the cervical vertebrae and includes five muscle-tendon actuators. This model was used together with experimental data to study the control of head movement.

	Tyrannosaurus Rex Model Ten degree-of-freedom model of the tyrannosaurus rex lower extremity. The model includes the kinematics of the hip, knee, ankle, and metatarsophalangeal joints and thirty-three muscle-tendon actuators.

SimTK Model Library

See the Neuromuscular Model Library on SimTK.org for even more models developed at research labs around the world.