Foot

The foot has 2 vital functions: to support the weight of the body in standing or walking and to act as a lever to propel the body forwards. The largest bone of the foot, the heelbone (see calcaneus), is jointed with the ankle bone (the talus). In front of the talus and calcaneus are the tarsal bones, which are jointed the 5 metatarsals. The phalanges are the bones of the toes; the big toe has 2 phalanges; all the other toes have 3. Tendons passing around the ankle connect the muscles that act on the foot bones. The main blood vessels and nerves pass in front of and behind the inside of the ankle to supply the foot. The undersurface of the normal foot forms an arch supported by ligaments and muscles. Fascia (fibrous tissue) and fat form the sole of the foot, which is covered by a layer of tough skin. Injuries to the foot commonly result in fracture of the metatarsals and phalanges. Congenital foot abnormalities are fairly common and include club-foot (see talipes), and claw-foot. A bunion is a common deformity in which a thickened bursa (fluid-filled pad) lies over the joint at the base of the big toe. Corns are small areas of thickened skin and are usually a result of tight-fitting shoes. Verrucas (see plantar warts) develop on the soles of the feet. Athlete’s foot is a fungal infection that mainly affects the skin in between the toes. Gout often affects the joint at the base of the big toe. An ingrowing toenail (see toenail, ingrowing) commonly occurs on the big toe and may result in inflammation and infection of the surrounding tissues (see paronychia). Foot-drop is the inability to raise the foot properly when walking and is the result of a nerve problem.