Anatomy & Background
The ankle is made up of two joints. These joints need to be strong because they support the weight of the entire body. The ankle is one of the most versatile joint complexes in the body. It is built for weight bearing, mobility, adaptability and stability. The foot and ankle allow us to walk, stand, run and jump, and serve as our connection to the ground. The ankle must be able to withstand the stress of our body weight, and also be able to adapt to, and react quickly to changes in environment and walking surface.
The ankle joint and subtalar joint are held together by ligaments, which connect bone to bone. There are three major ligaments on the lateral (outside) aspect of the ankle. The inside (medial) aspect of the ankle has a complex of several ligaments. These structures provide stability and flexibility to the ankle.
There are different degrees of instability of the ankle. Instability is typically characterized as the feeling of the ankle joint “giving out” and is generally caused by damage to the ligaments in the ankle joint. Ankle Instability can be either lateral (along the outside) or anterior (along the front).
Lateral Ankle Instability
There are three major ligaments on the lateral (outside) aspect of the ankle; they are the anterior talofibular ligament, the posterior talofibular ligament, and the calcaneofibular ligament. Lateral Ankle Instability often occurs due to an injury or damage to one of the lateral ankle ligaments.
Anterior Ankle Instability
The anterior area of the ankle is the front, or top of the ankle. The ligaments in this area include the anterior talofibular ligament and that anterior tibiotalar ligament. These ligaments can become damaged, causing subsequent instability of the ankle.
- Weakness of the lower leg or ankle muscles and laxity of the ankle ligaments are the most common cause of ankle instability.
- General ligament laxity may predispose an individual to instability or dislocations.
- Repetitive strain injuries (RSI) at work, or overuse activities are common in people who participate in sport activities and individuals who have jobs that require performing repetitive activities.
- Those participating in activities characterized by repetitive motions (jumping, running, etc.) that may aggravate the ankle, resulting in ankle instability.
- Sudden trauma or accident like a fall on the ankle.
Signs and Symptoms of Ankle Instability
- General tenderness of the ankle area
- Discomfort with movement, especially with flexing the ankle
- Feeling that the ankle is “dead” after repeated activity
- A feeling that the ankle will “go out” when moving in certain positions. This is called the “Apprehension Sign.”
- Significant pain in the ankle
- Swelling, weakness, numbness and occasional bruising of the ankle area.
Treating Ankle Instability
Conservative treatment of ankle instability includes physical therapy to reduce inflammation and associated pain. In addition, a regimen of exercises to improve muscle strength and ankle stability should be initiated. The use of a brace and other ankle supports may be indicated during rehabilitation and used as a preventive measure. In more severe cases of instability involving other joint structures, surgical intervention may be necessary.
Procedures that your physician may recommend and perform in addition to physical therapy include:
- Initial immobilization of the unstable ankle with boot or air-cast
- REST and ICE
- The use of NSAIDS (Non-Steroidal Anti-Inflammatory Drugs)
- Steroidal Injections to reduce any inflammation
- Pain medication to reduce the discomfort and allow the patient to perform the recommended exercises
- Physical Therapy that includes strengthening and working on balance for ankle stability retraining
- Surgery to correct underlying pathology and avoid instability and repeated dislocations. This may include surgical repairs or procedures to tighten the ankle ligaments.
Most people recover full function following a course of conservative care of physical therapy to strengthen and stabilize the ankle. Those with more involved situations such as ligament tears, or chronic dislocations will require surgery and intensive physical therapy afterward to restore full function.