The olecranon process (the elbow point) belongs to the ulna. Because the ulna does not rotate, the elbow point always faces away from the direction of the palm's rotation. Use it as an anchor point.
To capture the motion of the arm and hand in your sculptures, keep the following tips in mind:
The radius rotates over the stationary ulna. This action twists the forearm muscles diagonally. The brachioradialis wraps tightly across the top of the forearm, shifting the maximum volume of the forearm toward the thumb side. 3. The Hand: A Mechanical Masterpiece
To take your anatomy skills further, you can explore specialized books, breakdown videos, and interactive 3D sheets. If you would like to explore specific areas to improve your current sculpting project, let me know: