Dorsal Compartments

Question 1

Compartment One

Answer 1

Extensor Pollicis Brevis (EPB)
ABductior Pollicis Longus (APL)

Located on the lateral (radial) side of the wrist. These tendons form the lateral border of anatomical snuffbox. They’re also the tendons that are inflamed in De Quervain’s tenosynovitis which causes pain and swelling near base of thumb leading to difficulty with grasping and pinching.

Question 2

Compartment Two

Answer 2

Extensor Carpi Radialis Longus (ECRL)
Extensor Carpi Radialis Brevis (ECRB)

This compartment is separated from compartment 3 by Lister’s tubercle, a bony prominence of the distal aspect of the radius.

Question 3

Compartment Three

Answer 3

Extensor Pollicis Longus (EPL)

This tendon forms the medial border of the anatomical snuffbox.

Question 4

Compartment Four

Answer 4

Extensor Digitorum (ED)
Extensor Indicis (EI)

Question 5

Compartment Five

Answer 5

Extensor Digiti Minimi (EDM)

Question 6

Compartment Six

Answer 6

Extensor Carpi Ulnaris (ECU)

Located on the medial (ulnar) aspect of the wrist.