The hand section breaks down finger flexion into cascading creases —why the thumb’s web space changes shape when you grip a sphere, or why the middle finger knuckle is the highest point in a fist. There’s also a brilliant spread on finger alignment (natural fanning vs. forced parallel).
Anatomy for Sculptors: Arm and Hand in Motion is a masterclass in applied visual anatomy. It won’t teach you to sculpt, but it will answer every “why does this shape look wrong?” question you’ve ever had about arms and hands. anatomy for sculptors arm and hand in motion
By Uldis Zarins and Sandis Kondrats