Jalkapohjat

Jalkapohjat, or the soles of the feet, are the undersides of the feet in humans. They consist of thick plantar skin with a specialized fat pad, the plantar fascia (plantar aponeurosis), intrinsic muscles, nerves, and the bones of the foot. The sole plays a central role in weight-bearing, shock absorption, propulsion, and balance.

Anatomy: The skin of the sole is thick and tough to resist shearing forces; the fat pad cushions impact, especially at the heel and ball. The plantar fascia extends from the calcaneus to the toes and helps maintain the arch of the foot. Intrinsic muscles such as abductor hallucis, flexor digitorum brevis, and abductor digiti minimi reside in the sole. The sole is innervated mainly by the medial and lateral plantar nerves, branches of the tibial nerve.

Structure and arches: The soles align with the medial and lateral longitudinal arches and the transverse arch; the underlying bones include the calcaneus, talus, navicular, cuneiforms, and metatarsals, stabilized by ligaments and fascia.

Function: They support body weight during standing, absorb shock during gait, aid in propulsion, and provide sensory feedback from mechanoreceptors that help with balance and gait.

Clinical notes: Common issues include plantar fasciitis, calluses and corns from pressure, metatarsalgia, and neuropathic changes in conditions such as diabetes. Footwear, orthotics, padding, and foot hygiene influence comfort and injury risk. Strengthening exercises for intrinsic foot muscles can help maintain arch support.

See also: plantar fascia, foot anatomy, orthotics.