simtk.org

Hello everyone,

JointReaction prints results to one storage file with the suffix "_ReactionLoads.sto". This file contains rows of time-stamped data containing the 3 force and 3 moment vector components of the reaction load at each joint specified. Each data column label includes all information about how the load is applied and expressed.But I can not find find more details about "ankle_r_on_talus_r_in_ground_pz".What does "pz" mean?
thanks,
hongjie

These links explain the convention used:

https://simtk-confluence.stanford.edu:8 ... s+Analysis
https://www.youtube.com/watch?v=ly4rhOOifO0

ankle_r_on_talus_r_in_ground_pz means: the reaction due to the ankle_r joint on talus_r body measured in ground frame.

pz means the z component of the point where the wrench (force and moment) is applied. It can be f[x|y|z] or m[x|y|z] for force and moment respectively.

The joint connects two bodies, the parent and child. You can either calculate the reactions on the parent or child body. Then you have to specify where to express/measure these quantities. They can be expressed in different reference frames. The most common choice is the ground frame which is always stationary, while other reference frames can move and rotate in the course of the movement.