OpenSim Workshop March 2013 Simulation of Obese Locomotion Biomechanics Workshop Goals: -Investigate...
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Transcript of OpenSim Workshop March 2013 Simulation of Obese Locomotion Biomechanics Workshop Goals: -Investigate...
![Page 1: OpenSim Workshop March 2013 Simulation of Obese Locomotion Biomechanics Workshop Goals: -Investigate the effects of individual muscle strength scaling.](https://reader036.fdocuments.net/reader036/viewer/2022083005/56649f165503460f94c2c4f4/html5/thumbnails/1.jpg)
OpenSim Workshop March 2013
Simulation of Obese Locomotion Biomechanics
![Page 2: OpenSim Workshop March 2013 Simulation of Obese Locomotion Biomechanics Workshop Goals: -Investigate the effects of individual muscle strength scaling.](https://reader036.fdocuments.net/reader036/viewer/2022083005/56649f165503460f94c2c4f4/html5/thumbnails/2.jpg)
OpenSim Workshop March 2013
Modeling Static Knee Alignment: Motivation
• Obese children have ~3X greater prevalence of knee malalignment vs. NO
• Malalignement as Obese adult >> much greater risk for development and progression of OA
• We want to quantify both the magnitude and the distribution of the knee joint contact force
![Page 3: OpenSim Workshop March 2013 Simulation of Obese Locomotion Biomechanics Workshop Goals: -Investigate the effects of individual muscle strength scaling.](https://reader036.fdocuments.net/reader036/viewer/2022083005/56649f165503460f94c2c4f4/html5/thumbnails/3.jpg)
OpenSim Workshop March 2013
Modeling Static Knee Alignment
What is the correct anatomical alignment?
?
![Page 4: OpenSim Workshop March 2013 Simulation of Obese Locomotion Biomechanics Workshop Goals: -Investigate the effects of individual muscle strength scaling.](https://reader036.fdocuments.net/reader036/viewer/2022083005/56649f165503460f94c2c4f4/html5/thumbnails/4.jpg)
OpenSim Workshop March 2013
Modeling Static Knee Alignment
• For this exercise, we kept the tibiofemoral joint parallel to the ground
• Added two bodies (femoral condyles, tibial plateau)
• Updated joint definitions (articulations)
θ
Varus alignment
![Page 5: OpenSim Workshop March 2013 Simulation of Obese Locomotion Biomechanics Workshop Goals: -Investigate the effects of individual muscle strength scaling.](https://reader036.fdocuments.net/reader036/viewer/2022083005/56649f165503460f94c2c4f4/html5/thumbnails/5.jpg)
OpenSim Workshop March 2013
Modeling Static Knee Alignment
• Also made a model with valgus alignment
![Page 6: OpenSim Workshop March 2013 Simulation of Obese Locomotion Biomechanics Workshop Goals: -Investigate the effects of individual muscle strength scaling.](https://reader036.fdocuments.net/reader036/viewer/2022083005/56649f165503460f94c2c4f4/html5/thumbnails/6.jpg)
OpenSim Workshop March 2013
Check: Make sure muscles aren’t passively stretched i.e. musculo-tendon unit is the same between a neutral and malaligned knee
Modeling Static Knee Alignment
e.g. Semitendinosus
![Page 7: OpenSim Workshop March 2013 Simulation of Obese Locomotion Biomechanics Workshop Goals: -Investigate the effects of individual muscle strength scaling.](https://reader036.fdocuments.net/reader036/viewer/2022083005/56649f165503460f94c2c4f4/html5/thumbnails/7.jpg)
OpenSim Workshop March 2013
Modeling Static Knee Alignment
• Reran IK>RRA>SO>JR for Valgus, Varus, and Neutral Alignment
![Page 8: OpenSim Workshop March 2013 Simulation of Obese Locomotion Biomechanics Workshop Goals: -Investigate the effects of individual muscle strength scaling.](https://reader036.fdocuments.net/reader036/viewer/2022083005/56649f165503460f94c2c4f4/html5/thumbnails/8.jpg)
OpenSim Workshop March 2013
Modeling Static Knee Alignment
• Axial Force
• Largest with Varus alignment (Not Expected, I expected neutral)
Result of forcing alignment on neutral subject
![Page 9: OpenSim Workshop March 2013 Simulation of Obese Locomotion Biomechanics Workshop Goals: -Investigate the effects of individual muscle strength scaling.](https://reader036.fdocuments.net/reader036/viewer/2022083005/56649f165503460f94c2c4f4/html5/thumbnails/9.jpg)
OpenSim Workshop March 2013
Modeling Static Knee Alignment
• Knee Abd/Add Moment
• Largest with Varus alignment (Expected, Obvious)
Add
Abd
![Page 10: OpenSim Workshop March 2013 Simulation of Obese Locomotion Biomechanics Workshop Goals: -Investigate the effects of individual muscle strength scaling.](https://reader036.fdocuments.net/reader036/viewer/2022083005/56649f165503460f94c2c4f4/html5/thumbnails/10.jpg)
OpenSim Workshop March 2013
Proof of Concept: Can incorporate radiographic knee alignment to better understand loading in future childhood obesity study
Take home message: Critical to incorporate frontal plane knee alignment if you intend to calculate medial-lateral distribution!
Future:
• Balance forces and moments to resolve *approximate* medial-lateral distribution
• Incorporate med-lat calculation in a JR plugin
Modeling Static Knee Alignment
![Page 11: OpenSim Workshop March 2013 Simulation of Obese Locomotion Biomechanics Workshop Goals: -Investigate the effects of individual muscle strength scaling.](https://reader036.fdocuments.net/reader036/viewer/2022083005/56649f165503460f94c2c4f4/html5/thumbnails/11.jpg)
OpenSim Workshop March 2013
Thank you, OpenSim Team!