The dorsum of the wrist is subdivided into six compartments

The dorsum of the wrist is subdivided into six compartments. The PIN is the only nerve found in the dorsal compartments. It is consistently found on the base of the fourth compartment. Anatomic structures within each compartment are:

Compartment 1: Abductor pollicus longus, extensor pollicus brevis.

Compartment 2: Extensor carpi radialis longus and brevis

Compartment 3: Extensor pollicus longus

Compartment 4: Extensor digiti communis, extensor indicis propius, posterior interosseous nerve

Compartment 5: Extensor digiti minimi

Compartment 6: Extensor carpi ulnaris