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Dear Friends,

I am trying to run a forward dynamic simulation to depict an acceleration/deceleration of a car occupant. Since the simulation took time, I initially ran the analysis without muscles in order to verify the contacts and prescribed forces. The simulation worked fine. But when I added muscles and ran the code again on opensim the result was that the muscles seperated from the body after 10% of the simulation.
I tried finding the issue myself but to no vain.
I would appreciate any thoughts on what might be going wrong.

Thanks

What are the muscles connected to? It sounds like you have connected the attachment points to the Ground; when the simulation begins, the bodies move while the Ground stays stationary.

jimmy wrote:What are the muscles connected to? It sounds like you have connected the attachment points to the Ground; when the simulation begins, the bodies move while the Ground stays stationary.

Hey James,

I have connected the muscles to specific points on the respective bodies. The problem is that the muscle stays along with the body for certain duration of the simulation but after, say 15%, of the simulation, the muscles somehow stays in its new position and the bodies starts shifting away. . Your insight will be helpful.

It sounds like the muscle may be attached to a different body than the geometry you're visualizing. It would be easier to diagnose if you provide the files and instructions to reproduce the issue.

tkuchida wrote:It sounds like the muscle may be attached to a different body than the geometry you're visualizing. It would be easier to diagnose if you provide the files and instructions to reproduce the issue.

I solved this problem. There were issues with the contraintset and on rectifying those the model behaved ideally. Thanks guys

Glad you got it working. Thanks for posting the resolution.