The aim of this project is to provide detailed and well-validated musculoskeletal models of the thoracolumbar spine and rib cage, particularly for investigators with an interest studying musculoskeletal loading in the trunk.
These models include a fully articulated thoracolumbar spine (T1 through L5), with 3 rotational degrees-of-freedom at each inter-vertebral joint, and ribcage (24 individual ribs and a sternum). They also include a lumped head and neck body, and upper extremities. Major lumbar spine and abdominal muscle groups were incorporated from the previously developed OpenSim lumbar spine model (https://simtk.org/projects/lumbarspine), and muscles attaching to the upper and mid-thorax were adapted from the neck musculoskeletal model (https://simtk.org/projects/neck_mechanics) and upper extremity model (https://simtk.org/projects/up-ext-model). Additional muscle groups were added, including the external and internal inter-costals, the thoracic multifidus, the lower portion of the trapezius, the serratus anterior, and the transversus abdominis. Muscle measurements from in vivo computed tomography scans of the trunk were used to adjust the cross-sectional area (CSA) and position of the trunk muscles in the model to match a community-based sample of 125 men (generic male models) or 125 women (generic female models). The current release includes generic male and female models trunk models (v1.1), and generic male and female full body models (v1.2) that incorporate lower extremities from the Gait2354 model (https://simtk-confluence.stanford.edu/display/OpenSim/Gait+2392+and+2354+Models). In total the trunk models have 93 degrees-of-freedom, and 552 musculotendon actuators; full body models have 111 degrees of freedom and 620 musculotendon actuators.
The models are validated for estimations of spinal loading and trunk muscle tension against previously collected in-vivo measurement of intradiscal pressure, vertebral compression from telemeterized implants and trunk muscle EMG. The current models (v1.1 and 1.2) are created and validated in OpenSim 3.3, and may be used in Static Optimization analyses; we have not verified use in Computed Muscle Control. For more information, see our paper describing model development and validation: https://www.ncbi.nlm.nih.gov/pubmed/25901907
Also see our webinar: http://opensim.stanford.edu/support/event_details.html?id=143
In a related project, these models have been adapted to create full body models for children and adolescents: https://simtk.org/projects/spine-children
We have released a set of subject-specific models created for 250 individuals (125 men, 125 women, ages 41 - 90) from the Framingham Heart Study: https://dataverse.harvard.edu/dataverse/SpineModeling
We are currently using these models to study variations in spine loading in the population, including effects of spine curvature and variability in loading in different activities, as well as how this relates to the risk of vertebral fractures in older adults. See our publications list for recent papers.
Generic male and female models are available for download:
Trunk models (v1.1) and Full Body models (v1.2)
A spine loading tutorial is available under the Documents tab.
The project owner recommends the following other projects: