Trouble with scaling of gait10dof18musc.osim

[Iris Magnusdottir]

Hi OpenSim community.

I am having trouble with scaling of gait10dof18musc.osim model. I have a scale setup file and marker set file that works fine when scaling gait2354.osim. I have edited the files so </IKCoordinateTask> match my current model. I did expect the scaling to work for both models as they share the same body segments.

When scaling the gait10dof18.musc my marker locations shift to the right, resulting in high error (total squared error = 0.94358, marker error: RMS=0.177349, max=0.232176).

Does anyone have a suggestion on how this can be fixed?

When I load generic model and add the markers (prior to scaling) they appear on the model.
I have tried various setup files with different marker weights.

All feedback highly appreciated,
Iris Drofn

[Dimitar Stanev]

The problem with the scaling might be due to the fact that this model has a reduced number of degrees of freedom and is used for sagittal plate movement. If you want to properly scale this model, you should add all the degrees of freedom that exist in the original gait model (e.g., hip abduction/rotation, pelvis translation rotations) and after scaling you can lock them again. This will enable the model to achieve the pose of the static trial during scaling.