Anterior compartment of arm contains biceps brachii and brachialis innervated by the musculocutaneous nerve.
The anterior compartment of the arm (also called the flexor compartment) contains muscles responsible for flexion of the elbow and shoulder, as well as forearm supination. It is bounded by the brachial fascia and separated from the posterior compartment by the medial and lateral intermuscular septa. It also houses major neurovascular structures including the musculocutaneous nerve and brachial artery.
Structure | Description |
---|---|
Anterior | Brachial fascia and skin |
Posterior | Humerus and intermuscular septa |
Medial & Lateral | Medial and lateral intermuscular septa |
Muscle | Origin | Insertion | Function | Innervation |
---|---|---|---|---|
Biceps brachii |
Long head: supraglenoid tubercle Short head: coracoid process |
Radial tuberosity and bicipital aponeurosis | Flexes elbow, supinates forearm, weak shoulder flexion | Musculocutaneous nerve (C5–C6) |
Brachialis | Distal anterior surface of humerus | Coronoid process and tuberosity of ulna | Main flexor of the elbow (regardless of forearm position) | Musculocutaneous nerve (C5–C6), radial nerve (partial) |
Coracobrachialis | Coracoid process of scapula | Medial surface of humerus (midshaft) | Flexes and adducts the shoulder | Musculocutaneous nerve (C5–C7) |
In quadrupeds, the anterior compartment is less prominent due to reduced elbow flexion demands. In humans, it is well-developed to support carrying, lifting, and tool manipulation — functions dependent on controlled forearm positioning and strength.