static optimization doesn't report some muscle forces

[vahid F]

Hi everyone,

I want to use static optimization (SO) to extract muscle forces. But some of the muscle's color turn to gray during running SO and doesn't report force and activation for these muscles. What can be the source of this problem?

I'll be extremely thankful if someone tells me how to fix it.

Bests,

opensim_snapshot.png (446.81 KiB) Viewed 509 times

[Ayman Habib]

Hello,

Gray colored muscles are supposed to indicate that the muscles are disabled and so do not contribute to force calculations. If this is not the case please file a bug and attach all the necessary files and steps to reproduce.

Best regards,
-Ayman

[vahid F]

Hi Ayman, thanks for your quick response,

As you can see in the attached figure, the "applies force" option is selected but it doesn't work. These muscles apply force when using CMC but in static optimization, they don't.

Capture.PNG (252.29 KiB) Viewed 427 times

[vahid F]

This attachment contains all the necessary files to reproduce the results.

Best regards,
vahid

report_bug.rar

(267.98 KiB) Downloaded 20 times

[Najoua Assila]

Hi,

I have tried reproducing your error with the files you sent.
With the same setup, all muscles were activated using Opensim 4.0, but similar to what you reported some muscles weren't activated using Opensim 4.1.
So it's most probably a bug. Accordingly, as Ayman suggested, you should file a bug here: https://simtk.org/tracker/?group_id=91

Najoua.