plantar

Plantar is an anatomical term meaning related to the plantar surface, or sole, of the foot. The word derives from Latin planta, meaning the sole of the foot. In medical usage, plantar describes structures, surfaces, or conditions associated with the sole.

The plantar surface bears weight during standing and locomotion and houses the plantar fascia (plantar aponeurosis), a thick connective tissue band extending from the calcaneus to the proximal phalanges that helps maintain the foot’s arches. The sole contains intrinsic muscles arranged in four layers. The first layer includes abductor hallucis, flexor digitorum brevis, and abductor digiti minimi. The second layer contains quadratus plantae and the lumbricals. The third layer includes flexor hallucis brevis, adductor hallucis, and flexor digiti minimi brevis. The fourth layer houses the plantar interossei and dorsal interossei. The plantar surface is innervated primarily by the medial and lateral plantar nerves, branches of the tibial nerve, which supply motor function to the intrinsic muscles and sensory information from the sole.

The plantar region receives blood supply from branches of the posterior tibial artery. Clinically, plantar terminology covers conditions such as plantar fasciitis (inflammation of the plantar fascia causing heel pain), plantar warts (verruca plantares caused by human papillomavirus), and plantar ulcers (often seen in diabetes or vascular disease). The plantar reflex is a neurological test of the sole; an abnormal Babinski sign in adults indicates corticospinal tract dysfunction.