Chronic ankle instability is a condition in which a person’s ankle is weakened (usually from an ankle sprain or other injury) and therefore continuously gives out or twists on the outer (lateral) side. The condition is considered chronic if the ankle gives out within six months of a first ankle sprain or if the ankle is sprained again within six months of a previous sprain.
People with chronic ankle instability often experience moments when their ankle suddenly gives out and is unable to support the weight of the body. It usually occurs during walking, but it can happen during any type of physical activity, including standing.
In addition to frequently giving out, the ankle may experience persistent swelling, tenderness, pain and a feeling of instability.
Most cases of chronic ankle instability stem from previous ankle sprains and injuries that either did not heal fully or that did not heal properly. The muscle, tendon and ligament weakness that results from the first injury can then lead to further sprains and injuries if they’re not given the chance to fully heal and re-strengthen. These repeated injuries can permanently weaken and stretch the ankle’s ligaments, which eventually leads to chronic ankle instability.
Chronic ankle instability can affect anyone, but it most often occurs in athletes. According to the American Orthopaedic Foot and Ankle Society (AOFAS), about 30% of people who experience an ankle sprain will develop chronic ankle instability.
As with many foot problems and deformities, conservative non-surgical treatment is often recommended first. Some methods that can help chronic ankle instability include physical therapy to help strengthen the muscles and ligaments in the ankle and foot, bracing to help with ankle support and nonsteroidal anti-inflammatory drugs (NSAIDs) to help reduce any pain and swelling.
If the ankle instability is severe, your doctor may recommend surgery that repairs or reconstructs the weakened muscles and ligaments in the ankle. The type of surgery depends on each individual case, as does the surgery recovery time.
The best way to prevent chronic ankle instability is to avoid ankle injuries and sprains. You can do this by wearing properly fitted shoes suited for the type of activity you are engaging in, improving your balance and strengthening your ankle muscles via stretches and exercise.
If you have already experienced an ankle sprain, be sure that your muscles, tendons and ligaments are fully healed before engaging in physical activity. Strength and coordination exercises following full rehabilitation can also help prevent chronic ankle instability from developing. Those who engage in strengthening exercises are able to resume normal activity several weeks earlier than those who do not.