Musculus coracobrachialis
The coracobrachialis is a relatively small muscle that originates on the coracoid process of the scapula and inserts on the medial surface of the proximal humerus (near the teres major tuberosity). Its main actions are to adduct the shoulder and assist in protraction of the forelimb. It is innervated by the musculocutaneous nerve (C6–C7). A small synovial bursa or tendon sheath is often present at its origin. Compared with some other species, the muscle is modest in size in the horse. Isolated clinical problems are uncommon, but the bursa can become inflamed and the muscle can be involved in more extensive shoulder-region trauma.
Origin: Coracoid process of the scapula
Insertion: Medial surface of the proximal humerus (teres major tuberosity)
Action: Adducts the shoulder; assists in protraction of the forelimb
Innervation: Musculocutaneous nerve (C6-C7)
Coracobrachial bursitis is occasionally reported as a cause of shoulder lameness. Ultrasound can identify the muscle and bursa. Most shoulder lameness work-ups focus on the biceps tendon/bursa, suprascapular nerve, or joint itself; the coracobrachialis is a secondary consideration.
## Overview Shoulder adductor strain is injury to the muscles that pull the forelimb toward the midline. It occurs from lateral slipping or splaying of the front legs. Signs include reluctance to add
Persistent shoulder-region lameness that does not respond to rest should be evaluated by a veterinarian familiar with equine shoulder problems. Most minor muscle strains improve with controlled exercise.
## Overview Shoulder adductor strain is injury to the muscles that pull the forelimb toward the midline. It occurs from lateral slipping or splaying of the front legs. Signs include reluctance to adduct the limb, a base-wide stance, pain deep in the axilla, and a shortened stride. ## Causes Acute abduction overload. ## Diagnosis Palpation of the medial shoulder and axilla. ## Treatment Rest and anti-inflammatories. ## Recovery and Prognosis Good. ## Prevention Safe footing. Signs include: reluctance to adduct the forelimb; base-wide stance; pain on deep palpation in the axilla; shortened stride
Coracobrachial bursitis is occasionally reported as a cause of shoulder lameness. Ultrasound can identify the muscle and bursa. Most shoulder lameness work-ups focus on the biceps tendon/bursa, suprascapular nerve, or joint itself; the coracobrachialis is a secondary consideration.
Persistent shoulder-region lameness that does not respond to rest should be evaluated by a veterinarian familiar with equine shoulder problems. Most minor muscle strains improve with controlled exercise.
See the Coracobrachialis on our interactive 3D horse model. Open 3D Model