Quadratus plantae

The quadratus plantae (also quadratus plantae muscle, flexor accessorius, latin: musculus quadratus plantae) is a muscle of the sole of the foot that aids in flexion to the second to fifth toes.

Origin

The muscle fibers quadratus plantae arise as two heads (separated by the lateral plantar ligament) from the calcaneal tuberosity and the lateral plantar ligament.

Insertion

The quadratus plantae inserts into the tendon of the flexor digitorum longus.

Action

The main function of the quadratus plantae is to aid in flexing the second to fifth digits of the foot.

Innervation

The quadratus plantae is innervated by the lateral plantar nerve, one of the terminal branches of the tibial nerve.