Use marker data from OpenCap for Scaling

[Jeevinthiran Karunagaran]

Hello,

Will it be possible for me to use the marker data file (.trc) from OpenCap to scale an OpenSim model? I am trying to use a different model to the default one existing in OpenCap and I can't seem to get the scaling done manually. Could AddBiomechanics come up with a general scaling xml file for my particular model for me to include into my own OpenSim simulation?

-Jeevin

[Jeevinthiran Karunagaran]

I tried doing what I mentioned in the above post and I keep getting the following error.

Code: Select all

['/app/../engine/engine.py', '/tmp/tmp_i7j9d8_/', 'Karthikraj', '<private_file>']
exit: -11

I'm not sure what the cause could be.

[Nicholas Bianco]

Hi Jeevinthiran,

It should be possible to do what you describe. Could you please provide any error messages that appear on the subject page after you attempt your workflow so we can help resolve the issue?

-Nick

[Jeevinthiran Karunagaran]

Hello Nick

I have tried putting in only one trial for my subject as advised in our office hours discussion. I am using the thoracolumbar spine and rib cage model with markers placed matching (as close as possible) the ones used in OpenCap. However, I land with the same error.

Code: Select all

['/app/../engine/engine.py', '/tmp/tmppqpfsadm/', 'subject08', '<private_file>']
exit: -11

The simulation fails quickly after it starts processing. Could it be that the number of markers are just not enough (there are 43)?

[Nicholas Bianco]

Hi Jeevinthiran,

This seems like a genuine bug. Could you open an issue on GitHub and attach any files needed to reproduce the bug?

Open an issue here: https://github.com/keenon/AddBiomechanics/issues.

Best,
Nick

[Jeevinthiran Karunagaran]

Hello Nick,

I have posted the issue as requested.

Regards,
Jeevin

[Nicholas Bianco]

Thanks Jeevin,

We'll take a look at this bug during our development meetings and hopefully find a fix soon.

Best,
Nick

[Jeevinthiran Karunagaran]

Hello Nick,

Any updates on what this error could mean and how I could solve it? Because I input the default unscaled OpenCap LaiUlrich2022 model as a custom model with the trc file from a recording I made in OpenCap into AddBiomechanics and it was able to scale that properly (comparable to OpenCap's own scaling method with a neutral pose trial) and carry out IK successfully.

However when using the full body model with the same markerset used above, AddBiomechanics fails and I get the same error as mentioned above ( exit: -11) and in the issue I reported. This would mean that the markerset and the number of markers should not be an issue and there is likely a difference in the models that is causing the scaling to fail.

More information on what that error is could give me a lead on how to solve the problem.

Regards,
Jeevin

[Nicholas Bianco]

Hi Jeevin,

I couldn't say where the source of the error is without manually debugging. We haven't gotten around to it yet, but we'll hopefully take a look into this soon.

Best,
Nick

[Jeevinthiran Karunagaran]

Hello Nick,

Thank you for all your work!

Regards,
Jeevin