Standing Neutral Pose Problem in Non Ambulatory Subject

New project for OpenCap, which is a new software package to estimate 3D human movement dynamics from smartphone videos. OpenCap strongly relies on OpenSim.
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Arafat Rahman
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Standing Neutral Pose Problem in Non Ambulatory Subject

Post by Arafat Rahman » Thu Nov 09, 2023 8:19 am

Hi,
I am trying to use opencap to collect data from some spinal muscular atrophy (SMA) and duchenne muscular dystrophy (DMD) patients. But they are non ambulatory patients. They can not stand for neutral pose collection. They always sit in the wheelchair. Also, I am interested in upper limb motions. So, I don't need the lower limb muscle analysis.

Is it possible to collect neutral pose while they are sitting or is there any way to skip the neutral pose collection step? Thanks in advance for your answer.

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Scott Uhlrich
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Re: Standing Neutral Pose Problem in Non Ambulatory Subject

Post by Scott Uhlrich » Thu Nov 09, 2023 1:29 pm

Hi Arafat,

Yes, you can try running the neutral pose when seated, the scaled model will likely not be great since we assume standing-like hip-knee-ankle angles, but it should process. If it processes, you can then proceed with the collection and reprocess the data locally after the fact (https://github.com/stanfordnmbl/opencap ... essions.py). In reprocessing, you'd want to change the scaling setup file to remove all of the IKCoordinateTasks (https://github.com/stanfordnmbl/opencap ... A.xml#L620). Once you reprocess the neutral trial (and visualize that it looks representative in the webapp), you'd want to reprocess all of the dynamic trials as well.

Scott

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Arafat Rahman
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Re: Standing Neutral Pose Problem in Non Ambulatory Subject

Post by Arafat Rahman » Tue Nov 14, 2023 10:32 pm

I tried to record a neutral pose while sitting. But every time some errors are coming. Sometimes it says failed to record static pose because the subject was not stand still for 0.1 s. Sometimes it says camera synchronization failed.

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Scott Uhlrich
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Re: Standing Neutral Pose Problem in Non Ambulatory Subject

Post by Scott Uhlrich » Wed Nov 15, 2023 10:25 pm

Try again with the hrnet pose model. As of yesterday it is now the default, so just try collecting again. Make sure at least 2 cameras can see every body part.

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