Foot Issues

Ankle Sprain and Instability


A ligament is made up of multiple strands of connective tissue , similar to a nylon rope. A sprain results in stretching or tearing of the ligaments. Minor sprains only stretch the ligament. A tear may be either a complete tear of all the strands of the ligament or a partial tear of only some of the strands. The ligament is weakened by the injury; how much it is weakened depends on the degree of the sprain.

The lateral ligaments are by far the most commonly injured ligaments in a typical inversion injury of the ankle. In an inversion injury the ankle tilts inward, meaning the bottom of the foot angles toward the other foot. This forces all the pressure of your body weight onto the outside edge of the ankle. As a result, the ligaments on the outside of the ankle are stretched and possibly torn.

A severe form of ankle sprain, called an ankle syndesmosis injury, involves damage to other supportive ligaments in the ankle. This type of injury is sometimes called a high ankle sprain because it involves the ligaments above the ankle joint. In an ankle syndesmosis injury, at least one of the ligaments connecting the tibia and fibula bones (the lower leg bones) is sprained. Recovering from even mild injuries of this type takes at least twice as long as from a typical ankle sprain.


Initially the ankle is swollen, painful, and may turn ecchymotic (bruised). The bruising and swelling are due to ruptured blood vessels from the tearing of the soft tissues . Most of the initial swelling is actually bleeding into the surrounding tissues. The ankle swells as extra fluid continues to leak into the tissues over the 24 hours following the sprain.

People who have sprained an ankle often end up spraining the ankle again. If the ankle keeps turning in with activity, the condition is called ankle instability. Patients who have ankle instability lose confidence in their ankle to support them, especially on uneven ground. They often have swelling around the ankle that doesn’t go away. Pain and swelling in a joint can cause a reflex where the body turns off the muscles around the joint. This can cause times when the ankle feels like it is going to give way, meaning it may have a tendency to twist again very easily.

People who have had several mild ankle sprains or one severe sprain are prone to impingement problems in the ankle. The ligaments that were sprained may become irritated and thickened, causing them to get pinched near the edge of the ankle joint.