The ankle is the joint between the foot and leg, composed of three separate bones. The inner bone is the tibia, or shinbone, which supports most of a person's weight when standing. The outer bone is the fibula, or calf bone. The tibia and fibula are joined to the talus, or ankle bone, which is one of the major tarsal bones (bones at the back of the foot) and is located underneath the other two. This joint allows humans to walk, run, jump, and perform a variety of other actions. It permits movement and contributes to lower limb stability.
The joint allows for two distinct types of movement, called dorsiflexion and plantar flexion. Dorsiflexion involves the motion of the top part of the foot toward the leg. Plantar flexion is the opposite motion, in which the top of the foot moves away from the leg.
The ankle is reinforced by a number of ligaments that connect the bones of this joint. Ligaments are fibrous tissue that usually connect bone to bone. These include the deltoid, anterior talofibular, calcaneofibular, and posterior talofibular ligaments.