Marker placement in Stanford VA Upper Limb Model

[Xiaoyan Hu]

Hi All,

I'm using "Stanford VA Upper Limb Model", but it seemed that there are no markers attached to this model.
So where can I find the marker set for this model? or to add the markers manually? Is there any reference documents
that describe land marker placement according to anthropometry?

Thanks for help!
Xiaoyan

[Nicolas Eydieux]

Hi Xiaoyan,

Actually you have to add markers manually according to anatomical landmarks. To be able to follow accuratly the upper limb movement, I choose to put markers on xyphosternum, manubrium, C7, T8 and T12 for thorax part, on acromion of scapula, on epicondyles of humerus, on radial and ulnar styloid, and on third metacarpus for hand part.

This marker set depends on what movements you are interested in. For example, to be more precise with fingers movement you will have to add markers...

Hope that helps.
Nicolas

[Xiaoyan Hu]

Hi Nicolas,

Thank you for your reply, it helps me to figure out how to do marker placement in opensim in right way.
And thank you for sharing your marker set. I captured motion data from vicon. Is that mean I should define a set of markers according to the marker set in doing motion capture?


Best,
Xiaoyan

[Nicolas Eydieux]

Hi Xiaoyan,

Exactly, OpenSim will make inverse kinematics with your Vicon motion (after converting it from .c3d to .trc), so you have to put the same markers in your model as in your Vicon reconstruction.

Nicolas.

[Xiaoyan Hu]

Hi Nicolas,

Thank you very much for your help!

Best,
Xiaoyan