Author: Dr Peter de Souza
Last modified: 20 November 2023

The flexor hallucis brevis is one of the intrinsic muscles within the third layer of the plantar muscles of the foot.

The intrinsic muscles of the foot consist of one intrinsic muscle on the dorsal aspect of the foot (the extensor digitorum brevis), and 4 layers of muscles on the plantar aspect of the foot:

  • 1st layer: abductor hallucis, flexor digitorum brevis, abductor digiti minimi
  • 2nd layer: quadratus plantae, lumbricals
  • 3rd layer: flexor hallucis brevis, adductor hallucis, flexor digiti minimi brevis
  • 4th layer: dorsal interosseri, plantar interossei

Origin

  • Lateral head: plantar surface of cuboid and lateral cuneiform
  • Medial head: tibialis posterior tendon

Insertion

  • Lateral head: Lateral base of proximal phalanx of the great toe
  • Medial head: Medial base of proximal phalanx of the great toe

Action

  • Flexes great toe at metatarsophalangeal joint

Innervation

  • Lateral plantar nerve from tibial nerve: S1,S2

Blood Supply

  • 1st plantar metatarsal artery