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I am currently using the MoBL ARMS Dynamic Model of the Upper Extremity in OpenSim v3.1 64-bit version. I am using the Inverse Dynamics Tool to calculate joint torques during a simple shoulder abduction Inverse Kinematics trial. The Inverse Dynamics torques are not matching my direct torque calculations. I checked and rechecked my calculation, but still cannot find an explanation so I am beginning to wonder if there are any known issues with the Inverse Dynamics Tool in OpenSim 3.1 or with the MoBL ARMS Dynamic Model.

Thank you,
-Tyler

Hi,

How did you compute the torques for shoulder abduction? The shoulder joint is modeled differently in this model. Did you try to compute the moments with a simpler shoulder model (3DOF rotation)? Also, it is possible that the mass parameters are not specified correctly.

Regards