The Coracobrachialis is the smallest of the three muscles that attach to the coracoid process of the scapula

Scapula

In anatomy, the scapula , omo, or shoulder blade, is the bone that connects the humerus with the clavicle ....

. (The other two muscles are pectoralis minor and biceps brachii.) It is situated at the upper and medial part of the arm.

It is perforated by and innervated by the musculocutaneous nerve

Musculocutaneous nerve

The musculocutaneous nerve arises from the lateral cord of the brachial plexus, opposite the lower border of the Pectoralis major, its fibers being derived from C5, C6 and C7.-Path:...

.

Origin and insertion

It arises from the apex of the coracoid process, in common with the short head of the Biceps brachii, and from the intermuscular septum

Intermuscular septum

Intermuscular septum can refer to:* medial intermuscular septum of arm* medial intermuscular septum of thigh* lateral intermuscular septum of arm* lateral intermuscular septum of thigh...

 between the two muscles.

It is inserted by means of a flat tendon into an impression at the middle of the medial surface and border of the body of the humerus (shaft of the humerus) between the origins of the Triceps brachii and Brachialis.

Action

The coracobrachialis draws the humerus forward (shoulder flexion) and towards the torso (shoulder adduction).

Innervation

The coracobrachialis muscle is innervated by the musculocutaneous nerve which arises from the anterior division of the upper (C5, C6) & middle trunks (C7) of the brachial plexus.

External links

• PTCentral