Extensor pollicis brevis at a glance
- What it is
- A deep thumb extensor forming the lateral border of the anatomical snuffbox.
- Location
- Origin: posterior surface of the radius and interosseous membrane. Insertion: dorsal base of the proximal phalanx of the thumb.
- Function
- Extends the thumb at the metacarpophalangeal joint.
- Body system
- Muscular · paired (left and right)
- FMA ID
- FMA38519 (Foundational Model of Anatomy)
Key facts
- Innervation: posterior interosseous nerve (C7–C8)
- Its tendon shares the first dorsal compartment with abductor pollicis longus, and together they form the lateral (palmar) border of the anatomical snuffbox.
Clinical relevance
Its tendon sheath, with abductor pollicis longus, is involved in de Quervain tenosynovitis.
Structures next to the extensor pollicis brevis
The nearest named structures in the 3D model, measured from the centre of each part:
- Extensor pollicis longus · muscular
- Scaphoid · skeletal
- Flexor digitorum profundus · muscular
- Flexor pollicis longus · muscular
- Trapezium · skeletal
- Pronator quadratus · muscular
- Lunate · skeletal
- Capitate · skeletal
- Trapezoid · skeletal
- Dorsal carpal branch of radial artery · cardiovascular
References
- Foundational Model of Anatomy: Extensor pollicis brevis (FMA38519). EMBL-EBI Ontology Lookup Service.
- OpenStax. Anatomy and Physiology 2e, §11.2 Naming Skeletal Muscles. Rice University, 2022.
- Mitsuhashi N. et al. (2009). BodyParts3D: 3D structure database for anatomical concepts. Nucleic Acids Research 37, D782–D785. Data © The Database Center for Life Science, CC BY 4.0.
Related anatomy
Explore the whole body in the interactive 3D human anatomy model, or browse the A–Z list of human structures.