Musculi interossei pedis

Stored in the spatia interossea metatarsi (intermetatarsal spaces) and there are three plantar and four dorsal.

Musculi interossei plantares

 * I.–III. (numbered from the tibial side)

Origin: Tibial aspects of metatarsal bones III-V

Insertion: Tibial bases of proximal phalanges and extensor expansion of digits III-V

Innervation: n. plantaris lateralis (branch of nervus tibialis) (S1–S2).

Action: Toe flexion, toes adduction (grips the fan of the toes)

Musculi interossei dorsales

 * I.–IV. (numbered from the tibial side)

Origin: Opposing sides of metatarsal bones I-V

Insertion:

I: Tibial base of proximal phalanx of the second digit

II-IV: Fibular bases of proximal phalanges and extensor expansion of digits II-IV

Innervation: n. plantaris lateralis (branch of nervus tibialis) (S1–S2).

Action:

Metatarsophalangeal joints II-IV: toe flexion, toe abduction (closing the fan of the toes) - musculi lumbricales pedis synergists

Interphalangeal joints II-IV: toe extension