Anterior compartment of the forearm

Anterior Compartment of the Forearm

The anterior compartment of the forearm is a key anatomical region that contains muscles primarily involved in the flexion and pronation of the wrist and fingers. This compartment is delineated by the flexor retinaculum and the antebrachial fascia, and is divided from the posterior compartment of the forearm by the ulna and radius, the bones of the forearm.

Anatomy

The anterior compartment is separated from the posterior compartment by the interosseous membrane and is further divided into superficial and deep layers based on the muscles contained within each.

Superficial Layer

The superficial layer includes the following muscles:

• Pronator teres: Assists in pronating the forearm.
• Flexor carpi radialis: Flexes and abducts the wrist.
• Palmaris longus: Flexes the wrist and tenses the palmar aponeurosis.
• Flexor carpi ulnaris: Flexes and adducts the wrist.
• Flexor digitorum superficialis: Flexes the middle phalanges of the fingers.

Deep Layer

The deep layer contains:

• Flexor digitorum profundus: Flexes the distal phalanges of the fingers.
• Flexor pollicis longus: Flexes the distal phalanx of the thumb.
• Pronator quadratus: Pronates the forearm.

Blood Supply and Innervation

The anterior compartment is primarily supplied by the ulnar artery and the radial artery. The median nerve and the ulnar nerve are responsible for the innervation of the muscles in this compartment, with the exception of the flexor carpi ulnaris and the medial half of the flexor digitorum profundus, which are innervated by the ulnar nerve.

Clinical Significance

Conditions affecting the anterior compartment of the forearm include carpal tunnel syndrome, which is caused by compression of the median nerve, and pronator teres syndrome, a condition that mimics carpal tunnel syndrome but involves entrapment of the median nerve at the forearm. Understanding the anatomy of the anterior compartment is crucial for diagnosing and treating these conditions.

See Also

• Muscular system
• Forearm
• Flexor muscle
• Pronation and Supination