Corpus: Interosseous membrane of forearm

The interosseous membrane of the forearm is a fibrous membrane located between the two forearm bones, the ulna and the radius.

The interosseous membrane of the forearm extends from the interosseous crest of the radius obliquely to the medial and distal aspect of the interosseous crest of the ulna. It is wider in the middle than at both ends. In the upper part, the membrane is incomplete, beginning approximately 2 to 3 cm below the tuberosity of the radius. Near the lower margin, it has a small oval opening through which the anterior interosseous vein and artery, along with the anterior interosseous nerve, pass. In the proximal portion of the interosseous membrane of the forearm is a fiber bundle called the oblique cord that runs contrary to the main fiber direction. This prevents parallel displacement of the forearm bones.

The interosseous membrane of the forearm connects and stabilizes both forearm bones and serves as a broad muscle origin site for the following forearm muscles:

• Flexor pollicis longus muscle
• Flexor digitorum profundus muscle
• Pronator quadratus muscle
• Supinator muscle
• Abductor pollicis longus muscle
• Extensor pollicis brevis muscle
• Extensor pollicis longus muscle
• Extensor indicis muscle