I am trying to run CMC on 1 and 2 leg squat. I am having this issue that, if I just run the CMC for a very short interval around the time step of interest, it runs. But if I run CMC for a longer time interval (reducing the initial time, and increasing the final time), than one thing is that the simulation stops in b/w without giving any errors and I get different muscle forces?
eg: If I am interested in analyzing the muscle forces around t = 1.5, then if I run from say 1.3 to 1.7, then it gives some results, and if I run it from 1 to 2, then it may stop at 1.6 and will give different results for 1.3-1.6 as when I ran it from 1.3 to 1.7?
different time intervals, different results?
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Rahul Goel
- Posts: 13
- Joined: Thu Mar 05, 2009 12:31 pm
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Ayman Habib
- Posts: 2238
- Joined: Fri Apr 01, 2005 12:24 pm
RE: different time intervals, different results?
Hi Rahul,
If a simulation does not finish, I wouldn't trust any output from it.
If any of your muscles is maxing out then you shouldn't believe the forces you're getting since you're artificially influencing the choices of the optimizer. That may explain the differences in results because some muscles may max out earlier.
It's also known that the CMC optimizer is more likely to activate an antagonist muscle rather than deactivate a muscle (because deactivation time is longer).
Hope this helps,
-Ayman
If a simulation does not finish, I wouldn't trust any output from it.
If any of your muscles is maxing out then you shouldn't believe the forces you're getting since you're artificially influencing the choices of the optimizer. That may explain the differences in results because some muscles may max out earlier.
It's also known that the CMC optimizer is more likely to activate an antagonist muscle rather than deactivate a muscle (because deactivation time is longer).
Hope this helps,
-Ayman