Sprained ankle

Sprained ankle

A sprained ankle, also known as an ankle sprain, twisted ankle, rolled ankle, ankle injury or ankle ligament injury, is a common medical condition where one or more of the ligaments of the ankle is torn or partially torn.

Cause

Sprains happen when the foot is rolled or turned beyond motions that are considered normal for the ankle. An ankle sprain usually occurs when a person lands from jumping or running onto an uneven surface. If the ankle is placed into an abnormal position at the same time, overstretching of the ligaments can occur. The ligaments of the ankle hold the ankle bones and joint in position, and therefore help to stabilise the ankle joint. They protect the ankle joint from abnormal movements-especially twisting, turning, and rolling of the foot.

The risk of an ankle sprain is greatest during activities that involve explosive side-to-side motion, such as tennis or basketball, but you can also sprain your ankle during normal daily activities such as stepping off a curb or slipping on ice. If you return to sport or activity before the ligaments have fully healed, they may heal in a stretched position, resulting in less stability at the ankle joint. This can lead to a condition known as Chronic Ankle Instability (CAI), and an increased risk of ankle sprains.

The following factors can contribute to an increased risk of ankle sprains:

• Weak muscles/tendons that cross the ankle joint, especially the muscles of the lower leg that cross the outside, or lateral aspect of the ankle joint (i.e. peroneal muscles);
• Weak or lax ligaments that join together the bones of the ankle joint – this can be hereditary or due to overstretching of ligaments as a result of repetitive ankle sprains;
• Poor ankle flexibility;
• Lack of warm-up and/or stretching before activity;
• Inadequate joint proprioception (i.e. sense of joint position);
• Slow neuron muscular response to an off-balance position;
• Running on uneven surfaces;
• Shoes with inadequate heel support; and
• Wearing high-heeled shoes – due to the weak position of the ankle joint with an elevated heel, and a small base of support.

Types of Sprains

Inversion (Lateral) Ankle Sprain

The most common type of ankle sprain occurs when the foot is inverted too much, in which you roll over on the outside of your foot. When this type of ankle sprain happens, the outer, or lateral, ligaments are stretched too much. The anterior talofibular ligament is one of the most commonly involved ligaments in this type of sprain. Approximately 90% of ankle sprains are inversion injuries.

Eversion (Medial) Ankle Sprain

The other type of sprained ankle is called an eversion injury, in which you roll over on the inside of your foot. When this occurs, the medial, or deltoid, ligament is stretched too much.

High Ankle Sprain

A high ankle sprain is an injury to the large ligaments above the ankle that join together the two long bones of the lower leg, called the tibia and fibula. High ankle sprains commonly occur from a sudden and forceful outward twisting of the foot, which commonly occurs in contact and cutting sports such as football, soccer and basketball.

Classification

Ankle sprains are classified as grade 1, 2, and 3. Some of the most common causes of ankle injuries are: lack of conditioning, lack of warming up and stretching properly, previous history of an ankle sprain, inadequate shoes, and uneven ground. Depending on the amount of damage or the number of ligaments that are damaged, each sprain is classified from mild to severe. The amount of force that is placed on the ankle helps classify which grade of sprain is suffered. A mild sprain or one that causes slight stretching with minimal damage to the fibres in the ligament is considered a Grade 1 sprain. When there is some tearing of the ligament and the ankle joint moves in abnormal ways, it is noted to be a Grade 2 sprain. The final classification is Grade 3 sprain and includes severe injuries. These are ones where complete tears of a ligament and the presence of instability is experienced. Usually bruising will occur around the ankle but this can be prevented by putting ice on it and not putting it into hot water.

Symptoms

Knowing the symptoms that can be experienced with a sprain is important in determining that the injury is not really a break in the bone. When a sprain occurs, blood vessels will leak fluid into the tissue that surrounds the joint. White blood cells responsible for inflammation migrate to the area, and blood flow increases as well. Along with this inflammation, swelling from the fluid and pain is experienced. The nerves in the area become more sensitive when the injury is suffered, so pain is felt as throbbing and will worsen if there is pressure placed on the area. Warmth and redness are also seen as blood flow is increased. Also present is a decreased ability to move the joint, and difficulty using the affected leg.

Diagnosis

The diagnosis of a sprain relies on the medical history, including symptoms, as well as making a differential diagnosis, mainly in distinguishing it from strains or bone fractures. The Ottawa ankle rule is a simple, widely-used rule to help differentiate fractures of the ankle or mid-foot from other ankle injuries that do not require x-ray radiography. It has a specificity of nearly 100%, meaning that a patient who tests negative, according to the rule almost certainly does not have an ankle fracture.

Treatment

Conservative measures

Walking, heat, touching and expanding is often recommended.

If the ankle is not swollen, it just hurts to walk on and has limited mobilization, it is generally recommended that the injured wear an orthopedic walking boot for two weeks and be on crutches for the first week at least. Ice is often used to reduce swelling in cycles of 10–15 minutes on and 60–90 minutes off. Icing an ankle too long may cause cold injuries, indicated if the area turns white.

In uncomplicated lateral ankle sprains, swelling of the soft tissue can be prevented with compression around both malleoli, elevation of the injured ankle higher than the heart, and pain-free exercises.

An orthopedic walking boot is often used for the treatment of a sprained ankle injury. Braces and crutches are also used to help alleviate the pain so the injured ankle can heal as quickly and painlessly as possible.

Although found to be less effective than casts, compression bandages are used to provide support and compression for sprained ankles. Wrapping is started at the ball of the foot and slowly continued up to the base of the calf muscle, pushing the swelling up toward the center of the body so that it does not gather in the foot. Bandages are kept tight, but not so tight as to cut off the circulation in the foot.

Rehabilitation

If an ankle sprain does not heal properly, the joint may become unstable and may lead to chronic pain. Receiving proper treatment and performing exercises that promote ankle function is important to strengthen the ankle and prevent further injury.

Mobilization

A short period of immobilization in a below-knee cast or in an Aircast leads to a faster recovery at 3 months compared to a tubular compression bandage. Yet, a randomized controlled trial has concluded that appropriate exercise immediately after a sprain improves function and recovery. The exercises were focused on increasing ankle range of movement, activation and strengthening of ankle musculature, and restoring normal sensorimotor control, and were carried out for 20 minutes, three times a day.

The amount of therapy that a person can handle will depend on their level of pain and the grade of sprain they experienced. It is not recommended to return to sports or extreme physical activities until hopping on the ankle is achieved without pain. Wearing high-top tennis shoes may also help prevent ankle sprains if the shoes used are laced snugly and if the ankle is taped with a wide, nonelastic adhesive tape.

Ankle exercises

To prevent sprains or re-injury from occurring, strengthening and stretching exercises should be done through a full range of ankle motion. To improve ankle mobility, Ankle circles can be performed by extending the legs in front of the body and then moving the foot up and down, side to side, or rotating the foot in a circle. Another common exercise to improve mobility as well as proprioception is to use the toes to draw the letters of the alphabet in the air. Most importantly, the lateral aspect of the ankle joint should be strengthened with eversion exercises (i.e. underside of the foot is turned outward against resistance) to improve lateral ankle stability. Stretching is also an important component of a strengthening program, to help maintain joint flexibility.

Balance and stability training are especially important to retrain the ankle muscles to work together to support the joint. This includes exercises that are performed by standing on one foot and using the injured ankle to lift the body onto its toes. To further enhance balance and stability, exercise devices such as the Wobble board can be used, progressing from double-leg to single-leg stance, first with eyes open and then with eyes closed, for enhanced effectiveness.

Other strategies that can be used to prevent ankle injury include:

• Ensure proper warm-up prior to stretching and activity;
• When running, choose level surfaces and avoid rocks or holes;
• Ensure that shoes have adequate heel support; and
• If high-heeled shoes are worn, ensure that heels are no more than 2 inches in height, and avoid heels with a narrow base.

Prognosis

Most people improve significantly in the first two weeks. Some however still have problems with pain and instability after one year (5–30%). Reinjury is also common.

Image gallery

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  Right foot, housed in an air brace, has become swollen as a result of a more severe 2nd degree sprain to the ankle.
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  Swelling on left foot 30 minutes after injury.
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  Right foot. A light sprain, two days after injury. Patient had trouble walking normally for 2 months.
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  Right foot. One day after injury.

External links

• Overview at uchc.edu
• Ankle Sprains