Hi Francesca, Have you tried running the tool without adding external loads? From my experience, when adding the external loads (following instructions from https://simtk-confluence.stanford.edu:8443/display/OpenSim/How+to+Use+the+Inverse+Dynamics+Tool for a point force, using the non-normalized GRF...

Dear Thomas,

I have a question regarding the output of the simulations. Would it be possible to get the moment arms of the different muscles in the .sto file as well?

I look forward to hearing from you!

Best regards,
Kirsten