Compartments Deep to the Extensor Retinaculum

The extensor retinaculum is a fibrous band located at the dorsal aspect of the wrist, serving to stabilize the tendons of the extensor muscles as they pass through distinct compartments.

Anatomy and Function

The extensor retinaculum is divided into six compartments, each housing specific tendons. These compartments ensure smooth tendon gliding and prevent bowstringing during wrist movements.

Extensor Compartments

First Compartment: Houses the abductor pollicis longus and extensor pollicis brevis, crucial for thumb movements.
Second Compartment: Contains extensor carpi radialis longus and brevis, which facilitate wrist extension.
Third Compartment: Includes extensor pollicis longus, aiding thumb extension.
Fourth Compartment: Hosts extensor digitorum and extensor indicis, responsible for finger extension.
Fifth Compartment: Contains extensor digiti minimi, which extends the little finger.
Sixth Compartment: Houses extensor carpi ulnaris, contributing to wrist stability.