Flexor pollicis brevis at a glance
- What it is
- A thenar muscle medial to abductor pollicis brevis.
- Location
- Origin: flexor retinaculum, trapezium (superficial head) and capitate and trapezoid (deep head). Insertion: lateral side of the base of the proximal phalanx of the thumb.
- Function
- Flexes the thumb at the metacarpophalangeal joint.
- Body system
- Muscular · paired (left and right)
- FMA ID
- FMA37389 (Foundational Model of Anatomy)
Key facts
- Innervation: recurrent branch of the median nerve (superficial head) and ulnar nerve (deep head) (C8–T1)
- It is one of the few hand muscles commonly supplied by both median and ulnar nerves, which explains variable weakness after nerve injury.
- With abductor pollicis brevis and opponens pollicis it forms the thenar eminence.
Structures next to the flexor pollicis brevis
The nearest named structures in the 3D model, measured from the centre of each part:
- Superficial head of flexor pollicis brevis · muscular
- Oblique head of adductor pollicis · muscular
- Abductor pollicis brevis · muscular
- Opponens pollicis · muscular
- First metacarpal bone · skeletal
- Extensor indicis · muscular
- Trapezium · skeletal
- Transverse head of adductor pollicis · muscular
- Trapezoid · skeletal
- Deep palmar arch · cardiovascular
References
- Foundational Model of Anatomy: Flexor pollicis brevis (FMA37389). 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.