antebrachial

The antebrachial region, or antebrachium, refers to the forearm, the area between the elbow and the wrist. It contains the two long bones radius and ulna, joined by the interosseous membrane, and is wrapped by the antebrachial fascia. The region serves as the conduit for muscles, nerves, vessels, and tendons that control movements of the wrist, hand, and fingers, as well as forearm rotation.

Anatomically, the forearm is organized into two main fascial compartments: the anterior (flexor-pronator) compartment and the posterior (extensor-supinator) compartment, separated by the interosseous membrane. The anterior compartment houses flexor muscles such as pronator teres, flexor carpi radialis, flexor carpi ulnaris, flexor digitorum superficialis and profundus, and flexor pollicis longus; the brachioradialis is commonly described as part of the posterior region despite its forearm flexion function. The posterior compartment contains extensor and supinator muscles including extensor carpi radialis longus and brevis, extensor digitorum, extensor pollicis longus and brevis, extensor indicis, and the supinator.

Nerve and vascular supply are provided primarily by the brachial artery, with its radial and ulnar branches, and by the radial nerve (and its deep and superficial branches) and the median nerve, which innervate the respective compartments. Venous drainage parallels the arteries. Functionally, the forearm enables elbow flexion and forearm rotation (pronation and supination), as well as wrist and finger movements through the actions of its muscles and tendons.

Clinically, forearm injuries may involve fractures of the radius or ulna, compartment syndrome, or nerve palsies (notably median, ulnar, or radial nerve injury) that affect motor or sensory function in the region.