plantar ligament plantar ligament plantar ligament refer to ligaments in the sole of the foot: plantar plates, fibrocartilaginous structures in the metatarsophalangeal and interphalangeal joints of the toes. one of several tarsal, metatarsal, and tarsometatarsal ligaments: long plantar ligament, that connects the calcaneus with the cuboid bone plantar calcaneocuboid ligament, deep to previous plantar calcaneonavicular ligament, that connects the calcaneus with the navicular bone plantar cuneonavicular ligaments, that connect the navicular bone with adjacent cuneiform bones plantar intercuneiform ligaments, between the cuneiform bones plantar cuboideonavicular ligament, that connects the cuboid with the navicular bone plantar cuneocuboid ligament, that connects the cuboid with the cuneiform bones