Extensor pollicis longus at a glance
- What it is
- A thumb extensor whose tendon turns around the dorsal tubercle of the radius.
- Location
- Origin: posterior surface of the middle third of the ulna and interosseous membrane. Insertion: dorsal base of the distal phalanx of the thumb.
- Function
- Extends the distal phalanx of the thumb and assists in extension and adduction at other thumb joints.
- Body system
- Muscular · paired (left and right)
- FMA ID
- FMA38522 (Foundational Model of Anatomy)
Key facts
- Innervation: posterior interosseous nerve (C7–C8)
- Forms the medial border of the anatomical snuffbox
Clinical relevance
The tendon can rupture after a distal radius fracture.
Structures next to the extensor pollicis longus
The nearest named structures in the 3D model, measured from the centre of each part:
- Extensor pollicis brevis · muscular
- Flexor pollicis longus · muscular
- Flexor digitorum profundus · muscular
- Pronator quadratus · muscular
- Scaphoid · skeletal
- Trapezium · skeletal
- Extensor digitorum · muscular
- Lunate · skeletal
- Flexor digitorum superficialis · muscular
- Capitate · skeletal
References
- Foundational Model of Anatomy: Extensor pollicis longus (FMA38522). 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.