Brachial fascia encloses arm muscles and gives attachment to septa separating its compartments.
The brachial fascia is the deep fascia of the upper arm. It encases the muscles of the arm and contributes to the formation of distinct anterior (flexor) and posterior (extensor) compartments via intermuscular septa. This fascia supports muscular function, compartmental integrity, and serves as a conduit for neurovascular structures.
The brachial fascia envelops the entire arm, extending from the deltoid and pectoral fascia proximally to the antebrachial fascia distally near the elbow. It lies deep to the skin and superficial fascia and superficial to all arm muscles, nerves, and vessels.
The brachial fascia is a thickened sheet of connective tissue that:
Compartment | Contents | Innervation | Primary Function |
---|---|---|---|
Anterior (Flexor) | Biceps brachii, Brachialis, Coracobrachialis | Musculocutaneous nerve | Flexion of elbow and shoulder |
Posterior (Extensor) | Triceps brachii, Anconeus | Radial nerve | Extension of elbow |
While not directly visible, the brachial fascia contributes to the overall contour and firmness of the upper arm. It helps define the separation between biceps and triceps upon muscle contraction.
The brachial fascia forms from the condensation of mesenchymal connective tissue in the limb bud and becomes increasingly organized with musculoskeletal maturation.
In quadrupeds, the brachial fascia is generally thinner and more elastic. In humans, its denser structure supports complex upper limb movements involving strength, coordination, and precision grip.