OAR 436-035-0020: Parts of the Upper Extremities

(1) The arm begins with the head of the humerus. It includes the elbow joint. (2) The forearm begins distal to the elbow joint and includes the wrist (carpal bones). (3) The hand begins at the joints between the carpals and metacarpals. It extends to the joints between the metacarpals and the phalanges. (4) The thumb and fingers begin at the joints between the metacarpal bones and the phalanges. They extend to the tips of the thumb and fingers, respectively.