The bones which constitute the ankle are the two long bones of the lower leg (tibia
), which articulate with a short ankle bone called the talus
. This is an ‘uniaxial’, or hinge, joint, which allows flexion and extension movements. In the case of the ankle these movements are called dorsiflexion
(sole of the foot up) and plantarflexion
(foot down) respectively. Plantarflexion is achieved by the calf muscles (gastrocnemius
), which form a large strong tendon (Achilles tendon
) which inserts into the bone of the heel (calcaneum
). This tendon is not uncommonly a site of injury in athletes. Dorsiflexion is achieved by muscles at the front of the lower leg (peroneal muscles
), and damage to their nerve supply can result in ‘foot drop’ — an inability to lift the end of the foot requiring higher lifting of the knee during walking. The joints below the ankle (sub-talar
joints) permit movements of the sole of the foot inward (inversion
) and outwards (eversion
), which are important when walking on uneven surfaces. A common problem is ‘going over’ or twisting the ankle, often occurring when walking on uneven ground. This can result in injury ranging from a minor sprain (tearing of some fibres of a ligament) through to complete rupture of ankle ligaments, sometimes also accompanied by fracture of the lower end of the tibia or fibula. Sprains and fractures are often followed by swelling of the soft tissues in the injured area, due to fluid leaking from blood vessels at the site of injury, and also bruising (‘black and blue’ discolouration of the skin) due to blood leaking from torn vessels.
William R. Ferrell
See also feet
an·kle / ˈangkəl/ •
n. the joint connecting the foot with the leg. ∎ the narrow part of the leg between the foot and the calf.•
v. 1. inf. [tr.] leave: he ankled the series to do a movie. ∎ [intr.] walk.2. [intr.] [usu. as n.] (ankling) flex the ankles while cycling in order to increase pedaling efficiency.
ankle (an-k'l) n. 1.
the hinge joint between the leg and the foot. It consists of the talus (ankle bone), which projects into a socket formed by the lower ends of the tibia and fibula. 2.
the whole region of the ankle joint, including the tarsus and the lower parts of the tibia and fibula.