Motion capture collection and pasting method

[li shuaifu]

Hello, I want to conduct an experiment according to the motion capture patch collection given in your paper. Can you give a specific usage plan for the patches, especially the patch method for thighs and calves. Thank you.

[Scott Uhlrich]

Hello, I'm not exactly sure what you mean by patches, but if you mean tracking marker clusters, we use between 3 and 5 tracking markers on semi-rigid plates affixed to the lateral sides of the shanks and thighs. The markers are arranged so there are one or more orthogonal triads per plate.

Since we use OpenSim's inverse kinematics approach for getting kinematics from markers, we do not explicitly create reference frames from the tracking markers, but rather, they are tracked in the inverse kinematics optimization problem. Setup files for our inverse kinematics problem can be found here https://github.com/stanfordnmbl/opencap ... ipeline/IK

[li shuaifu]

Hello, thanks for the reply. I wanted to apply the Mocap points according to the given method in the literature, but I found that we did not have load-bearing and calf gaiters in our experiment. Do you have specific models of these two?
2. In addition, there are two points R_HJC and L_HJC. How are they attached? I think Opensim planted them inside the pelvis. How are they marked?

[Scott Uhlrich]

I'm not sure what you mean by load-bearing calf gaiters? Can you state it another way?

We use functional hip joint center trials to compute the hip center markers as described here: https://pubmed.ncbi.nlm.nih.gov/14757454/ . The individual moves their hip through a star pattern as well as a maximum range-of-motion circle.