Unrealistic IAA results from CMC
Posted: Fri Feb 15, 2019 10:16 am
I am working on IAA from CMC results to get muscles contributions to the knee adduction, internal rotation, and flexion acceleration during single-leg landing trials. And the model has 5 deg of freedom of the knee joint. I used CMC_controls.xml, CMC_states.sto, GRF, and rolling on surface constraint for the IAA analysis.
Here is the problem.
When I choose "compute potentials only", all the muscle's contributions look very identical. And they all have negative values.
However, if I uncheck "compute potentials only", the results have positive and negative values.
From what I understand, compute potential only is used to get acceleration per unit force. In this case, results from "compute potentials only" and results from unchecking this option should be the same in terms of the direction, not magnitude.
And the results from "compute potential only" looks unrealistic since the contributions to knee adduction acceleration are very similar regardless of where the muscles are originated and inserted from.
I was wondering if someone would give me some advice on the issue.
Let me know if you need additional details.
Thanks!
Here is the problem.
When I choose "compute potentials only", all the muscle's contributions look very identical. And they all have negative values.
However, if I uncheck "compute potentials only", the results have positive and negative values.
From what I understand, compute potential only is used to get acceleration per unit force. In this case, results from "compute potentials only" and results from unchecking this option should be the same in terms of the direction, not magnitude.
And the results from "compute potential only" looks unrealistic since the contributions to knee adduction acceleration are very similar regardless of where the muscles are originated and inserted from.
I was wondering if someone would give me some advice on the issue.
Let me know if you need additional details.
Thanks!