The coracobrachial muscle is a flat muscle which arises ont the coracoid process of the scapula. Its tendon of origin emerges between the supraspinous and the subscapular muscles, where it is protected by a synovial bursa. It extends caudodistally over the medial aspect of the shoulder joint and ends on the teres major tuberosity of the humerus as well as further distal on the medial aspect of the humerus shaft. It extends and adducts the arm, and rotates the shoulder joint outward.
Origin: Coracoid process of the scapula.
Insertion: Crest of the lesser tubercle of the humerus in dogs, or around teres major tuberosity and medial aspect of the humerus shaft in other species.
Action: Extension and adduction of the shoulder joint.