Based on the methodology of Uldis Zarins, Anatomy for Sculptors
Using the PDF’s skeletal spreads, identify the three fixed points of the arm in motion: arm and hand in motion by anatomy for sculptors pdf verified
In motion, these three points form a specific triangle. If your triangle doesn't match the PDF, your arm will look dislocated. Based on the methodology of Uldis Zarins, Anatomy
The deltoid is the mechanical bridge from the torso to the arm. In motion, these three points form a specific triangle
Downloading a arm and hand in motion by anatomy for sculptors pdf verified is only the first step. Here is how to integrate it into a sculpting workflow (traditional clay or ZBrush/Blender).
If you locate a verified copy, here is the specific knowledge you will gain that you cannot find in free blogs: