The Probert Encyclopaedia of Medicine

QUADRATUS PLANTAE

The quadratus plantae (flexor accessorius; pronator pedis) lies on the sole of the foot. It has two heads that originate from the lateral and medial border of the calcaneus and inserts in the tendons of the flexor digitorum longus. This muscle assists the flexor digitorum longus in flexing the toes for the final push-off in walking and running. It also flexes the foot. The quadratus plantae is innervated by the plantar nerve and supplied by the plantar artery.
Research Quadratus Plantae