The plantar plate is a fibrocartilage structure located at the ball of the foot. The ball of the foot involves a joint which anatomically is called the metatarsal phalangeal joint (MTP) joint. The MTP joint is where the long foot bone (metatarsal) meets the toe (phalanx).
Each toe in the foot has an MTP joint which is numbered 1 through 5. The plantar plate allows the foot to absorb the enormous forces of walking and running in addition to limiting extension (1). There are ligaments that attach the plantar plate to the long bones of the foot which are illustrated by the red and blue bands in the picture. The plantar plate and the supporting ligament provide critical stability for the MTP joint (1)