Placing greater trochanter markers on model

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Eric Rapp
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Joined: Fri Aug 31, 2018 2:58 pm

Placing greater trochanter markers on model

Post by Eric Rapp » Tue Jan 29, 2019 4:33 pm

Hello,

I am currently using the Rajagopal model for my analysis in OpenSim. It includes all the markers that were used in the experimental data collection except for three, the sacrum and left/right greater trochanter. I placed these markers on the generic model at estimated locations. However, these markers are the ones that seem to have the highest error during scaling, so I am wondering if the markers are not in the correct location.

My question is, are there any resources that state where these markers (particularly the GTR markers) should be placed on a model in relation to the ASIS markers? Or is there already a good estimate out there? I am fairly new to OpenSim and optoelectronic data collection, and the data I am using was captured by someone else.

I have attached images of the model with the markers placed in estimated locations and without any muscles visible.
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Wayne Yin
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Joined: Thu Aug 30, 2018 11:50 am

Re: Placing greater trochanter markers on model

Post by Wayne Yin » Tue Jan 29, 2019 5:00 pm

In the tutorial, it says that when you do scaling, select the "Preview static pose (no marker movement)", then you could find the location of the virtual markers of the model and the experimental makers of your data in the visualizer. After doing this, you can drag the virtual markers to the experimental markers and do scaling again.
However, I just found that this function, "Preview static pose (no marker movement)" , does not work in OpenSim 4.0. I have posted a reply about this issue to James Dunne. Hope he could give us help.

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Eric Rapp
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Joined: Fri Aug 31, 2018 2:58 pm

Re: Placing greater trochanter markers on model

Post by Eric Rapp » Wed Jan 30, 2019 7:34 am

Thank you for the reply, and once that feature is functional I will check it out.

Any other suggestions in the mean time?

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