Anterior region of forearm

The anterior region of forearm refers to the anterior compartment of the forearm, which is the flexor-pronator compartment.

Boundaries

• Medially: Defined by the subcutaneous border of the ulna.

• Laterally: Formed by the radius and the brachioradialis muscle.

• Proximally: An imaginary line connecting the humeral epicondyles.

• Distally: The wrist crease.

Muscles and Function

The anterior region of forearm houses muscles primarily responsible for flexion of the wrist and digits, as well as pronation of the forearm. These muscles are arranged in three layers:

• Superficial Layer: Includes the pronator teres, flexor carpi radialis, palmaris longus, and flexor carpi ulnaris.

• Intermediate Layer: Comprises the flexor digitorum superficialis.

• Deep Layer: Consists of the flexor digitorum profundus, flexor pollicis longus, and pronator quadratus.

Innervation

The majority of these muscles receive their innervation from the median nerve. Notable exceptions include the flexor carpi ulnaris and the medial part of the flexor digitorum profundus, both of which are supplied by the ulnar nerve.

Neurovascular Supply

The arterial supply is predominantly provided by the radial artery (coursing laterally) and the ulnar artery (coursing medially). Key neural structures traversing this region include:

• The median nerve, which typically courses centrally.

• The ulnar nerve, positioned more medially.

• Cutaneous innervation to the region is provided by the lateral antebrachial cutaneous nerve (laterally, often accompanying the cephalic vein) for the lateral aspect, and the medial antebrachial cutaneous nerve for the medial forearm sensation.