Change location of a joint

[Míriam Febrer-Nafría]

Hello,
I'm trying to do a simulation of a prosthesis (the shoulder joint) surgery.
I have changed the location of the joint in the model, but I don't know if I have to change also the rotation axis, or another parameter.

I mean, I want to start my analysis on a model that will be a patient after surgery, so it will have a prosthesis instead of his own shoulder joint.
I don't know if only changing the joint location, the model will represent correctly that situation.
I also don't know if what I'm trying to do is possible to do with OpenSim.

Thank you,
Miriam

[Maria Isabel Orselli]

Hi Mirian,

It is possible to change the location of your joint using OpenSim. You have just to modify the values on your .osim file representing the model.
you can do this using a xml editor :

http://simtk-confluence.stanford.edu:80 ... els-Joints

or you can use the user interface in the program. In the 'Windows' tab you can open the "Properties" panel , then you just select the joint you want to edit in the model and change the properties.

about your concern regarding the rotation axes I think I can't help much! I just can give an opinion: If you think that after the surgery there is a significant change in the patients axes of rotation, than you should try modeling that. And you can do this following the above procedures (look for the SpatialTransform property).

Hope it helps,
Bel

[Míriam Febrer-Nafría]

Thanks, Bel,
I have changed the joint location and also the axis, looking at the SpatialTransform property.