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Scaling problem

Posted: Tue Oct 03, 2023 8:34 am
by denouel.l
Hi,

I'm looking to model the execution of a Timed-up-and-go by patients.

To do this, I'm using a model of 30 markers that I've scaled to the patients' marker coordinates.
The problem is that the scaling doesn't work very well: my pelvis is constantly tilted to the right (see photo).
I tried other models, I tried manually to correct the posterior markers of the pelvis by modifying them to correct this tilt, it is better, but it does not correct the problem on all patients.
Inverse kinematics' results gives me an unstable pelvis that moves too much.

Do you have any ideas for solutions ?

Thanks

Re: Scaling problem

Posted: Sun Oct 08, 2023 10:27 pm
by mahshida
can you share the marker file and the trc file, It will give a better idea of the said problem.

Re: Scaling problem

Posted: Thu Oct 12, 2023 1:48 pm
by umerhuzaifa
Hi there,

For anyone who is still trying to figure out these issues, there most likely is a misalignment of the experimental data in TRC and the OpenSim Coordinate convention. Since you cant change the convention in OpenSim, you will have to rotate the collected data appropriately.

I hope this helps.

Umer

Re: Scaling problem

Posted: Fri Oct 13, 2023 2:48 pm
by kernalnet