When using ProCalc, the first step is to define what you want ProCalc to calculate, ie, which particular biomechanical model (or other calculation) should be produced.
This tutorial explains how to implement the lower body Conventional Gait Model (CGM) version 2.3, known as CGM2.3. This version of CGM has been developed by Fabien Leboeuf at Salford University, UK.
For more information, see:
https://pycgm2.github.io/pages/CGM23-Overview.html
The marker set for CGM2.3 looks like this (for clarity, only the left side is shown):
The marker set is similar to earlier versions of CGM, but uses medial markers at the knee and ankle to determine the frontal planes of the femur and tibia.
Extra tracking markers are used on the anterior aspect of the thighs and shanks.