Ankle

The ankle, the talocrural region or the jumping bone (informal) is the area where the foot and the leg meet. The ankle includes three joints: the ankle joint proper or talocrural joint, the subtalar joint, and the inferior tibiofibular joint. The movements produced at this joint are dorsiflexion and plantarflexion of the foot. In common usage, the term ankle refers exclusively to the ankle region. In medical terminology, "ankle" (without qualifiers) can refer broadly to the region or specifically to the talocrural joint.

The main bones of the ankle region are the talus (in the foot), the tibia, and fibula (both in the leg). The talocrural joint is a synovial hinge joint that connects the distal ends of the tibia and fibula in the lower limb with the proximal end of the talus. The articulation between the tibia and the talus bears more weight than that between the smaller fibula and the talus.

The ankle region is found at the junction of the leg and the foot. It extends downwards (distally) from the narrowest point of the lower leg and includes the parts of the foot closer to the body (proximal) to the heel and upper surface (dorsum) of the foot.

The talocrural joint is the only mortise and tenon joint in the human body, the term likening the skeletal structure to the woodworking joint of the same name. The bony architecture of the ankle consists of three bones: the tibia, the fibula, and the talus. The articular surface of the tibia may be referred to as the plafond (French for "ceiling"). The medial malleolus is a bony process extending distally off the medial tibia. The distal-most aspect of the fibula is called the lateral malleolus. Together, the malleoli, along with their supporting ligaments, stabilize the talus underneath the tibia.

Because the motion of the subtalar joint provides a significant contribution to positioning the foot, some authors will describe it as the lower ankle joint, and call the talocrural joint the upper ankle joint. Dorsiflexion and Plantarflexion are the movements that take place in the ankle joint. When the foot is plantar flexed, the ankle joint also allows some movements of side to side gliding, rotation, adduction, and abduction.

The bony arch formed by the tibial plafond and the two malleoli is referred to as the ankle "mortise" (or talar mortise). The mortise is a rectangular socket. The ankle is composed of three joints: the talocrural joint (also called talotibial joint, tibiotalar joint, talar mortise, talar joint), the subtalar joint (also called talocalcaneal), and the Inferior tibiofibular joint. The joint surface of all bones in the ankle is covered with articular cartilage.

The distances between the bones in the ankle are as follows:

Decreased distances indicate osteoarthritis.