The ankle is a weight-bearing joint where three bones meet - the tibia and fibula of the lower leg and the talus of the foot, which sits on top of the heel bone (calcaneus). Ligaments, strong bands of fibrous tissue capable only of slight stretch, hold the bones together. Tendons attach muscles to the bones to move the ankle joint, and are softer and more stretchy. Any of these structures - the bones, ligaments and tendons - can be injured, and this leaflet explains some of the common injuries that can occur to your ankle.
The ankle is complicated joint and it is commonly injured. For most of our evolution, animals with a backbone and skeleton (vertebrates), such as human beings, have walked on four legs. When mankind evolved to walk on just two legs the ankle was given quite a lot of extra work to do, both in weight bearing and in balance. It’s perhaps not surprising, then, that the ankle is prone to strains, sprains and fractures.
A strain refers to a painful condition of the ankle joint brought about by inflammation, overuse or simply awkward (or unbalanced) use. It includes inflammation of muscles and tendons such as the Achilles tendon at the back of the heel.
A sprain is an injury to the band which connects two or more bones to a joint. This band is called a ligament. A sprain is usually caused by the joint being forced suddenly outside its usual range of movement. Most sprains heal within a few weeks. A severe sprain may look and feel like a fracture, and it can be difficult for health professionals to tell the difference between the two.
A fracture is a break in one of the bones which make up the ankle joint. These are the leg bones (the tibia and fibula) and the heel and forefoot bones (the calcaneus and talus). Depending upon the exact cause of the fracture, one or more bones may be involved. Fractures cause sudden pain and usually cause significant swelling. Stress fractures are smaller cracks in the bone which also cause intense pain but with less dramatic swelling.
Ankle pain may also arise from existing conditions of the joint itself, such as arthritis or gout, which may be aggravated by movement, impact or strain.