Corpus: Interosseous membrane of the forearm

The Membrana interossea antebrachii is a connective tissue membrane between the two forearm bones ulna and radius.

The antebrachial interosseous membrane extends from the interosseous crest of the radius obliquely medially and distally to the interosseous crest of the ulna. It is wider in the centre than at either end. In the upper part, the membrane is incomplete, as it begins about 2-3 cm below the radial tuberosity. Near the lower edge it has a small oval opening through which the anterior interosseous vein and artery and the nerve of the same name (anterior interosseous nerve) pass.

In the proximal section of the antebrachial interosseous membrane there is a fibre tract that runs against the actual fibre direction, the chorda obliqua. This prevents parallel displacement of the forearm bones.

The Membrana interossea antebrachii connects and stabilises both forearm bones and serves as a broad muscle origin surface for the following forearm muscles:

• Musculus flexor pollicis longus
• Musculus flexor digitorum profundus
• Musculus pronator quadratus
• Musculus supinator
• Musculus abductor pollicis longus
• Musculus extensor pollicis brevis
• Musculus extensor pollicis longus
• Musculus extensor indicis (proprius)

See also: Interosseous membrane