GCMAS Tutorial 2015

I DOWNLOADED OPENSIM - NOW WHAT?

This introductory tutorial at the 2015 Gait and Clinical Movement Analysis Society (GCMAS) meeting will provide practical tips for getting started with OpenSim.

The workshop will take place on Wednesday March 18, 4-6pm. Participants will be introduced to OpenSim’s features, file formats, and documentation using HANDS-ON, clinically-relevant examples.

Full Abstract: OpenSimTutorial gcmas2015.pdf

Learning Objectives

OpenSim is open-source software that allows users to analyze and visualize models of the musculoskeletal system and to generate dynamic simulations of walking and other movements (see Delp 2007).  OpenSim is highly relevant to the GCMAS Community because it enables users to study the effects of musculoskeletal geometry, joint kinematics, and muscle-tendon properties on the forces and joint moments that muscles can produce.

By this end of this tutorial, participants will be able to:

• Identify components of an OpenSim model (GUI & XML)
• Load a model and animate it
• Use OpenSim's Plot Tool to plot muscle moment arms and other data
• Use OpenSim's Scale and Inverse Kinematics Tools to scale a model and solve for the model's joint angles from marker data
• Analyze a model to explain how force-generating capacity changes after a simulated surgery
• List the steps needed to process experimental data for input into OpenSim
• Locate OpenSim documentation, examples, and resources

Preparing for the Tutorial 

Participants should bring (or be prepared to share with a colleague) a laptop running the Windows operating system with OpenSim and Notepad++ installed.   Bring a computer mouse, too.

Before the tutorial:

(1) Please test your installations by completing the quick exercises posted below.

(2) Download the GCMAS tutorial files (coming soon).

Download OpenSim

OpenSim is hosted on SimTK, a cloud storage service for biomedical tools and research.  There are 32- and 64- bit versions available to correspond with your system requirements.  If you are unsure which version you need, click here.

Download Notepad++

OpenSim model files and setup files are written in xml.   Notepad++ is a free text editor that makes it easier to view and edit xml files.  During the tutorial we will use Notepad++ to examine OpenSim files.

Download the Pre-Tutorial Test Exercises

Please download and complete the following exercises PRIOR to the tutorial.   We've compiled these exercises to:

• Confirm that you've installed OpenSim correctly
• Introduce you to some useful features of OpenSim's GUI
• Help you configure Notepad++ to recognize OSIMM files as XML files

Download the GCMAS Tutorial Files

Download Guided Tutorial Exercise (pdf) 

Download Tutorial Slides (pdf)

Workshop Staff and Contact Information 

Allison Arnold (aarnold@oeb.harvard.edu) Concord Field Station, Harvard University	Apoorva Rajagopal (apoorvar@stanford.edu) Neuromuscular Biomechanics Laboratory, Stanford University
Chris Carty (c.carty@griffith.edu.au)  School of Allied Health Sciences, Griffith University	Kat Steele (kmsteele@uw.edu) Ability & Innovation Lab, University of Washington
James Dunne (james.dunne@stanford.edu) Neuromuscular Biomechanics Laboratory, Stanford University

Useful Links and Literature

National Center for Simulation Research (NCSRR) 

OpenSim Documentation (Confluence) 

Overview of the OpenSim Workflow

Preparing Your Data

Examples and Tutorials

OpenSim: Open-Source Software to Create and Analyze Dynamic Simulations of Movement  
Scott L. Delp, Frank C. Anderson, Allison S. Arnold, Peter Loan, Ayman Habib, Chand T. John, Eran Guendelman, and Darryl G. Thelen
IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, VOL. 54, NO. 11, NOVEMBER 2007

Is My Model Good Enough? Best Practices for Verification and Validation of Musculoskeletal Models and Simulations of Movement
Jennifer L. Hicks, Thomas K. Uchida, Ajay Seth, Scott L. Delp.
Journal of Biomechanical Engineering, Volume 137, Issue 2, 2015 

Muscle contributions to vertical and fore-aft accelerations are altered in subjects with crouch gait
KM Steele, A Seth, JL Hicks, MH Schwartz, SL Delp 
Gait & posture 38 (1), 86-91

Can biomechanical variables predict improvement in crouch gait?
JL Hicks, SL Delp, MH Schwartz
Gait & posture 34 (2), 197-201

Crouched postures reduce the capacity of muscles to extend the hip and knee during the single-limb stance phase of gait
JL Hicks, MH Schwartz, AS Arnold, SL Delp
Journal of biomechanics 41 (5), 960-967