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Hello everyone,

I'm wondering if anyone has seen/fixed this issue before:

I'm trying to use the "Associate Motion Data..." tab to add a marker.trc file to my IK results to visualize my experimental markers relative to my model markers. However, this isn't working, and I'm getting the error: "filename.trc cannot be associated to IKResults -- duplicate column labels encountered".

I thought this could be due to an error in the trc file, but the trc file was used to generate the scaled model without any issues, and I was able to associate the exact same trc file to the static pose generated from the Scale Tool. However, when I run IK, I have problems associating the trc file. I thought it could be that there are duplicate marker names in the trc file, but I've double checked and this is not the case.

Any thoughts?

Thanks so much,
Brody

Hi Brody,

I wouldn't use associate motion data (which is typically used to show objects that are attached to body/segments while in motion), instead you could use (File->Preview Experimental Data) which displays data in ground frame (as typically is the case for trc files). At this point you can synchronize the two motions to see how the two marker clouds relate to each other (model markers vs experimental markers).

The duplicate columns is likely due to the fact that OpenSim is trying to "merge" the two motions where the same markers appear in ground frame (trc) and on associated bodies (IK solution).

Hope this helps,
-Ayman

Thanks, Ayman! This is very helpful!

Best,
Brody