Muscles of the Upper Forelimb
Triceps Brachii
Long Head: Originates from the border of the scapula. Medial Head: Originates from the proximal portion of the humerus. Lateral Head: Originates from the proximal end of the humerus. All insert on the ulna. This muscle extends the forearm.
Biceps Brachii
Originates from the scapula. Inserts on the proximal ends of the radius and the ulna. This muscle is the primary flexer of the lower forelimb.