I am planning to investigate shoulder motion using MoCap data, focusing on kinematics and muscle forces. Since my interest is limited to the shoulder, I would like to reduce the marker set.
I’m starting from the full-body MoCap example model, and I see two possible approaches:
Delete the lower body from the model.
Keep the lower extremities but use drivers to fixate the lower body joints.
What would be the best practice for analyzing shoulder motion using MoCap data when a full-body marker set is not needed?
I would recommend switching off the leg model. You can add the following lines in the BodyModelConfig.any file that you can find through the LabSpecificData.any file:
#define BM_LEG_LEFT OFF
#define BM_LEG_RIGHT OFF
Please note the trunk and head can't be switched off, so please include markers for the trunk and head. And the arm, of course
Hello Dave,
thanks for the quick reply.
Since trunk and head can't be switched off - Could I use drivers instead of markers if I don't want to use markers (on the head) and instruct the participants to not move the head?
What would be an alternative? Does it even make sense to start with the full body MoCap model or would you suggest building a new model from scratch with only trunk and arms?
I think your approach with the head markers is fine. You can add weak mannequin drivers to drive the neck posture and instruct the subjects to keep their head still. You can see the list of mannequin drivers at this link.
The best approach is to start with one of the full body mocap examples. You could consider starting from the Simple Full Body mocap model. You would need to switch off the legs, comment out the markers on the leg in MarkerProtocol.any, and comment out some code for ForcePlates or GRF prediction that you can find through LabSpecificData.any.
I think that should be the simplest approach. It's way too complicated to build a mocap model from scratch
