simtk.org

Hello,
I am working with the gait 2392 model to retrieve the Inverse Kinematics and Inverse Dynamics from subjects. I am only interested in the knee and ankle joints result for my work. I am using the default marker set that came with the model. with this in mind what is the inverse dynamics calculations flow? I mean, in my case, will the head and torso affect the dynamics of the knee and ankle? if no, is it ok to remove those bodies?

Best regards,
Amged

will the head and torso affect the dynamics of the knee and ankle?

It depends how you have configured your model and simulation. (1) The Inverse Kinematics Tool solves a weighted least squares problem (see https://simtk-confluence.stanford.edu/d ... tics+Works). Depending on how the Tool has been configured, adding/removing body segments and markers from the upper body may change the solution for the lower body. (2) Removing the head and torso will change the mass of the model, which would change the solution from the Inverse Dynamics Tool. The RRA Tool can be used to address this type of model simplification, as demonstrated in the following example: "The Strength of Simulation: Estimating Leg Muscle Forces in Stance and Swing" (https://simtk-confluence.stanford.edu/d ... +and+Swing).