What is the ankle?

The ankle is large joint that, along with the bones of the foot, makes up the part of the skeleton responsible for balance and posture of body during different activities, whether static (standing) or dynamic (jumping, walking or running). It also plays an important role in bearing the entire weight of the body. In common usage, the term “ankle” refers solely to the ankle region, while in medical terminology; “ankle” refers to the broader region or most specifically, to the talocrural joint.  

The ankle is formed by the union between three bones: the shin bone (tibia), the thinner bone running next to the shin bone (fibula) and the foot bone that sits above the heel bone (talus). The medial malleolus (inner part of the tibia) form together with the lateral malleolus (outermost part of the fibula) in a sort of cup that surrounds the tarsus, preventing joint movement towards the outside. The mobility of the ankle is also limited to a series of ligaments which, while allowing a slightly lateral flexibility, are needed to maintain balance, help walking on uneven surfaces, and prevent dislocation of the joint. In particular, the talofibular ligaments (front and rear) and the calcaneofibular ligaments, combine the fibula to the bones of the foot in the lateral outside of the ankle, while on the inside, they are joined to the bones of the tarsus by the deltoid ligament (a strong, flat, triangular sort of band).

There are several conditions associated with injuries or diseases of the ankle. They include: sprained ankle, ankle fracture, high ankle sprain, gout, ankle fracture, septic arthritis, psoriatic arthritis, ankle arthritis, and rheumatoid arthritis. For example, most ankle sprains are often the result of a fall, sudden twist, or blow to the ankle joint. The severity of an ankle sprain depends on whether the ligament is stretched, partially torn or completely torn, as well as the number of ligaments involved.

Seeking proper medical assistance is essential in diagnosing an individual’s condition and helping determine the most appropriate form of treatment (surgery, immobilization, RICE therapy, pain medications, physical therapy etc), as well as preventing further complications from arising. Left untreated, even a simple sprained ankle can lead to chronic ankle instability or an even more severe injury.  


What function does the ankle serve?

The ankle is a joint which allows plantar flexion and dorsiflexion of the foot. Plantar flexion refers to the movement which decreases the angle between the sole of the foot and the back of the leg (ex: pointing the foot to the floor, as if to walk on one’s toes). Dorsiflexion is rather the opposite movement, where the toes are brought closer to the shin. This decreases the angle between the dorsum of the foot and the leg (ex: lifting the foot to walk on one’s heels).

The ankle is also equipped with some lateral mobility, which although limited, allows walking on uneven surfaces. This flexibility is possible in order to maintain balance when making a wide range of movements (such as walking, running, jumping, and other actions) allowed by the joint. If the ligaments within the ankle become injured for any reason, it can result in ankle instability.