Plantar interossei

The plantar interossei (Latin: musculi interossei plantares) are a group of three small plantar foot muscles located in the sole of the foot between the metatarsal bones. They belong to the central compartment (middle group) of the plantar foot muscles. The plantar interossei primarily provide adduction of the toes.

Origin

The plantar interossei muscles originate from the medial aspects of the third, fourth and fifth metatarsal bones.

Insertion

The plantar interossei insert on the extensor expansions and medial aspects of the bases of the proximal phalanges of the third, fourth and fifth fingers of the foot.

Action

The plantar interossei muscles provide toe flexion and adduction at the third to fifth metatarsophalangeal joints and toe extension at the third to fifth interphalangeal joints.

Innervation

The plantar interossei are innervated by the lateral plantar nerve (S2 - S3) - one of the terminal branches of the tibial nerve.

Blood supply

The plantar interossei muscles receive arterial blood supply from the lateral plantar artery - a branch of the posterior tibial artery.