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Markerset for Oxford foot model - simple relative motion

Posted: Tue Jan 24, 2023 4:47 am
by mlukas
Hi. I am looking for OFM marker set as I was unable to find it anywhere. Does it exist or do I have to manually create one myself?
Also I have gait motion capture data already converted into .trc and .mot and I only want to extract relative motion data of leg bones during specific phases of gait. Since I am completely new to this I have read most of the tutorials and forum, but all of them are rather complicated and seem too much for my implications. What would be the easiest way to go about that?
Thank you for your help in advance

Re: Markerset for Oxford foot model - simple relative motion

Posted: Tue Jan 24, 2023 12:17 pm
by nicos1993
Hey Milosz!

a) In the generic model you plan to use (e.g., the Rajagopal model) you will have to have move the model markers to the positions coinciding with the Oxford foot model, additionally you will need to label these markers with the same names as used in your motion capture software.

b) Performing inverse kinematics should be sufficient for what you described, however the quality of the results will very much dependent on the model you use and the motion capture data you acquired! I think this recent article published a detailed foot model for usage with OpenSim - https://www.tandfonline.com/doi/full/10 ... 21.1968844

Best wishes,

Nicos Haralabidis

Re: Markerset for Oxford foot model - simple relative motion

Posted: Sun Apr 30, 2023 2:57 am
by mlukaszewicz
Hi. Thank you for the response. I was able to use this multisegmental model to create Oxford foot model.
It works great in OpenSim 4.x. However BOPS, the script I want to use to batch process IK, is only compatible with OpenSim 3.3. And there is the issue. This model - https://simtk.org/frs/?group_id=2092 - should be compatible with OpenSim 3.3, but it doesn't open and I get this error:
Coordinate coupler: unknown independent coordinate knee_angle_r
or
Invalid coordinate (knee_angle) specified for TransformAxis translation2 in joint rfemoral-tibial
It is only true for full lowerlimb model, foot and ankle model (where the knee is absent) works fine.
How can I fix this issue? I would be grateful for any tips.

Kind regards,
Milosz