Look at the specific plate showing the arm twisting from palm up to palm down.
The book by Anatomy For Sculptors (A4S), authored by Uldis Zarins, is a specialized reference designed to help artists master the upper limb's complex deformations. It is the fourth title in the acclaimed A4S series and is widely considered a significant upgrade for artists struggling with the "nemesis" of hands and arms. Core Methodology and Content
Visual boundaries make it easy to track where a muscle originates and inserts during complex twists.
