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9 projects in result set.
OpenSim
- OpenSim is a freely available, user extensible software system that lets users develop models of musculoskeletal structures and create dynamic simulations of movement.
Find out how to join the community and see the work being performed using OpenSim at <a href="http://opensim.stanford.edu">opensim.stanford.edu</a>.
Access all of our OpenSim resources at the new <br /><a href="http://opensim.stanford.edu/support/index.html"><b style="color:#900; font-size:16px;">Support Site</b></a>.
Watch our <a href="http://www.youtube.com/watch?v=ME0VHfCtIM0">Introductory Video</a> get an overview of the OpenSim project and see how modeling can be used to help plan surgery for children with cerebral palsy.
<iframe width="560" height="315" src="https://www.youtube.com/embed/ME0VHfCtIM0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe> | |
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Registered: 2006-03-23 18:48 |
Full Body Model for use in Dynamic Simulations of Human Gait
- Our paper describes a full body OpenSim model with musculotendon parameters derived from experimental measurements of 21 cadaver lower limbs and magnetic resonance images of 24 young adult subjects. Our model is derived from the lower body model published by Arnold et al. (2010) and the tracking upper body by Hamner et al. (2013), but updates the muscle force distribution to reflect those of a young, healthy population, includes a new knee model to accurately represent internal forces, and simplified muscle wrapping surfaces to increase computation speed in CMC and other muscle-driven simulations. | |
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Activity Percentile: 93.56 Registered: 2012-06-11 22:52 |
Model of the Scapulothoracic Joint
- In this study, we developed a rigid-body model of a scapulothoracic joint to describe the kinematics of the scapula relative to the thorax. This model describes scapula kinematics with four degrees of freedom: 1) elevation and 2) abduction of the scapula on an ellipsoidal thoracic surface, 3) upward rotation of the scapula normal to the thoracic surface, and 4) internal rotation of the scapula to lift the medial border of the scapula off the surface of the thorax. The surface dimensions and joint axes can be customized to match an individual’s anthropometry. We compared the model to “gold standard” bone-pin kinematics collected during three shoulder tasks and found modeled scapula kinematics to be accurate to within 2 mm root-mean-squared error for individual bone-pin markers across all markers and movement tasks. As an additional test, we added random and systematic noise to the bone-pin marker data and found that the model reduced kinematic variability due to noise by 65% compared to Euler angles computed without the model. Our scapulothoracic joint model can be used for inverse and forward dynamics analyses and to compute joint reaction loads. The computational performance of the scapulothoracic joint model is well suited for real-time applications, is freely available as an OpenSim 3.2 plugin, and is customizable and usable with other OpenSim models. | |
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Activity Percentile: 88.64 Registered: 2015-01-14 23:10 |
Simulation of Constrained Musculoskeletal Systems in Task Space
- Objective: This work proposes an operational task space formalization of constrained musculoskeletal systems, motivated by its promising results in the field of robotics.
Methods: The change of representation requires different algorithms for solving the inverse and forward dynamics simulation in the task space domain. We propose an extension to the Direct Marker Control and an adaptation of the Computed Muscle Control algorithms for solving the inverse kinematics and muscle redundancy problems respectively.
Results: Experimental evaluation demonstrates that this framework is not only successful in dealing with the inverse dynamics problem, but also provides an intuitive way of studying and designing simulations, facilitating assessment prior to any experimental data collection.
Significance: The incorporation of constraints in the derivation unveils an important extension of this framework towards addressing systems that use absolute coordinates and topologies that contain closed kinematic chains. Task space projection reveals a more intuitive encoding of the motion planning problem, allows for better correspondence between observed and estimated variables, provides the means to effectively study the role of kinematic redundancy and, most importantly, offers an abstract point of view and control, which can be advantageous towards further integration with high level models of the precommand level.
Conclusion: Task-based approaches could be adopted in the design of simulation related to the study of constrained musculoskeletal systems.
The source code of the project can be found at: https://github.com/mitkof6/opensim-task-space.git
The new API of task space and constraint projection for OpenSim V4.0 is available at: https://github.com/mitkof6/task-space
<iframe width="560" height="315" src="https://www.youtube.com/embed/jfE14iWRZDs" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe> | |
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Registered: 2017-08-28 12:06 |
OpenSim Moco
- OpenSim Moco is a software toolkit to solve optimal control problems with musculoskeletal models defined in OpenSim, including those with kinematic constraints. Using the direct collocation method, Moco can solve a wide range of problems, including motion tracking, motion prediction, and parameter optimization. The design of Moco focuses on ease-of-use, customizability, and extensibility. Just like OpenSim itself, Moco has interfaces in XML/command-line, Matlab, Python, Java, and C++.
<ul style="line-height: 100%;">
<li><a href="https://opensim.stanford.edu/moco">Read the <b>documentation</b></a></li>
<li><a href="https://github.com/opensim-org/opensim-moco">View the source code, report bugs, suggest features, or contribute on <b>GitHub</b></a></li>
<li><a href="https://www.biorxiv.org/content/10.1101/839381v1">Read the Moco preprint on <b>bioRxiv</b></a></li>
<li><a href="https://github.com/stanfordnmbl/mocopaper">Obtain the models, data, and code used to produce the Moco preprint</a></li>
<li><a href="https://opensim.stanford.edu/support/event_details.php?id=236&title=Webinar-OpenSim-Moco-Software-to-optimize-the-motion-and-control-of-OpenSim-models">Watch the recording of the Moco <b>webinar</b> from November, 2019</a></li>
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Registered: 2019-11-03 22:27 |
Neuromusculoskeletal Modeling (NMSM) Pipeline
- <div style="display:inline-block"><a href="https://nmsm.rice.edu"><img src="https://nmsm.rice.edu/img/nmsm-pipeline-social-card.jpg" style="float:left;max-width:calc(100% - 40px);"></a></div>
Full project information is available at: https://nmsm.rice.edu. Please direct any inquiries about the NMSM Pipeline to us by posting your questions on this SimTK project forum or emailing nmsm@rice.edu.
Neuromusculoskeletal Modeling (NMSM) Pipeline is a set of tools for personalizing models and designing treatments for movement impairments and other pathologies.
The NMSM Pipeline consists of two toolsets:
Model Personalization - Personalize joint, muscle-tendon, neural control, and ground contact model properties.
Treatment Optimization - Design treatments using personalized models and an optimal control methodology.
At this time, Treatment Optimization requires the use of <a href="https://www.gpops2.com/">GPOPS-II optimal control solver</a>.
The NMSM Pipeline is written in MATLAB to lower the barrier for entry and to facilitate accessibility to the core codebase. We encourage users to modify the code to meet their needs.
The core codebase and examples are available to download for use in research. At this time, we ask that you wait to publish any work that uses the NMSM Pipeline until the journal article reference for the software is available. Please get in touch with us if you have any questions.
If you need help or want to start a discussion, please use the SimTK forum for this project.
Note: This project is a living entity. Updates will be made available as the Pipeline, examples, and tutorials are developed further and improved. | |
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Registered: 2022-07-07 14:55 |
Predictive Simulation of Standing Long Jumps
- This project is aimed at creating a predictive simulation framework for standing long jumps and studying how using a how such a framework can be used to study performance differences due to various perturbations.
In particular, we have used this framework to study how simulation can be used to aid in device design. In our publication, we first show that the framework could generate a simulation that captured salient features of a standing long jump, including kinematics and kinetics. We then used the framework to design active and passive devices to increase simulated jump performance. | |
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Registered: 2014-01-30 23:21 |
Lumbar Spine with Passive Elements
- The model files included a modified lumbar model with passive elements and a full body model incorporating this lumbar model. The files also included setting files of external loads (10·Nm moment in three principal axes) for ROM validation.
The ligaments in L3-S1 were modeled by Ligament elements. The rotational stiffness produced by intervertebral disc or facet articulation was modeled using ExpressionBasedBushingForce element.
The model was created based on other previously developed OpenSim models (https://simtk.org/projects/fullbodylumbar, https://simtk.org/home/lumbarspine, https://simtk.org/projects/intervertebr_jr, https://simtk.org/projects/ulb_project). | |
Registered: 2018-07-02 06:51 |
Data-tracking optimization using collocation
- PLEASE CITE THIS PAPER:
Lin, Y.-C. and Pandy, M. G. (2017). THREE-DIMENSIONAL DATA-TRACKING DYNAMIC OPTIMIZATION SIMULATIONS OF HUMAN LOCOMOTION GENERATED BY DIRECT COLLOCATION, Journal of Biomechanics, 59, 1-8. (https://www.ncbi.nlm.nih.gov/pubmed/28583674)
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Registered: 2016-09-27 03:03 |