Supination, semipronation, and forced pronation of the arm, Anatomy For Sculptors
The pictures show supination, semipronation, and forced pronation of the arm. During the latter, the elbow rotates outwards, indicating movement in the shoulder, where the deltoid muscle gets worked. Marked with the dots are the deltoid tuberosity, olecranon, and distal head of the ulna – the bony landmarks that help you follow the muscle attachments as the arm gets pronated. www.anatomy4sculptors.com