Inverse kinematics results

[Rodrigo Bini]

Hi,
just wanted to check if the output from inverse dynamics are internal or external moments. My question is because, during drop landing tasks, we are observing ankle dorsi flexion torque (external torque) with the appropriate muscle predicted forces via Static Optimisation (i.e. gastrocs, soleus, etc).
Thanks,
Rodrigo

[jimmy d]

we are observing ankle dorsi flexion torque (external torque)

That is because it is an internal force.

[Rodrigo Bini]

Hi James,

thanks for your response. However, I could not understand that.
If you land on your toes, the external forces lead your ankle to dorsi-flexion and the muscle response should be plantar-flexion, in terms of movement and moments. However, when we plot the output from Inverse Dynamics, we are observing that the ankle joint moment is dorsi-flexor. The same is being observed for other joints. Therefore, our question is if the output from ID provides you the external moment rather than the internal moment as a response from muscle contractions.
Thanks,
Rodrigo