A sprained ankle occurs following a sudden sideways or twisting movement of the foot. An ankle sprain can occur during athletic events or during everyday activities. All it takes is an awkward step or an uneven surface to cause an ankle sprain--that is why these injuries are among the most common orthopedic problems.
A sprained ankle usually occurs when a person lands from jumping or running on to an uneven surface. For example, sprained ankles are often seen when basketball players come down from a jump and land on another player's foot.1 Ankle sprains also occur with more routine daily activities such as stepping off a curb or slipping on ice.
An ankle sprain is an injury to the ligaments that support the ankle.2 The ligaments are structures that control excessive movement of the joint. When an ankle sprain happens, the ligament is stretched too far, and is either partially or completely torn.
There are two broad categories of ankle sprain:
Inversion Ankle Sprains
The most common type of ankle sprain occurs when the foot is inverted, twisting inwards. When this type of ankle sprain happens, the outer, or lateral, ligaments are stretched too far. There are three lateral ankle ligaments that support the outer side of the joint. About 90% of ankle sprains are inversion injuries.3 Pain is always on the outside of the ankle, and there is usually no to minimal pain on the inside of the joint.
Eversion Ankle Sprains
The other type of sprained ankle is called an eversion injury, where the foot is twisted outwards.4 When this occurs, the inner ligament, called the deltoid ligament, is stretched too far. Patients will have pain on the inner side of the ankle joint.
In addition, there is one variation called a high ankle sprain. These injuries have a more complex recovery as they involve the ligaments above the ankle as well as on the side of the joint.5 The ligament that connects the two bones of the leg is called the syndesmosis, and high ankle sprains involve injury to this ligament.
Ankle Sprain Symptoms
The most common signs of an ankle sprain include:
Swelling of the ankle joint6
Bruising around the ankle, sometimes into the foot and toes
Pain around the ankle
Difficulty bending the ankle up or down
Discomfort when trying to walk6
The degree of symptoms tends to correlate well with the extent of the damage to the ligaments. Most doctors use a grading system to categorize ankle sprains. Keep in mind, these are broad categories, and not every grade I ankle sprain behaves exactly the same. These categories do give an injured athlete a sense of the severity of injury and the prognosis for recovery.
Grade I Ankle Sprain:
Grade I ankle sprains cause stretching of the ligament. The symptoms tend to be limited to pain and swelling.2 Most patients can walk without crutches, but may not be able to jog or jump.
Grade II Ankle Sprain:
A grade II ankle sprain is more severe partial tearing of the ligament. There is usually more significant swelling and bruising caused by bleeding under the skin. Patients usually have pain with walking, but can take a few steps.
Grade III Ankle Sprain:
Grade III ankle sprains are complete tears of the ligaments. The ankle is usually quite painful, and walking can be difficult. Patients may complain of instability, or a giving-way sensation in the ankle joint.2
As said before, pain and swelling are the most common symptoms of an ankle sprain. Patients often notice bruising over the area of injury.4 This bruising will move down the foot towards the toes in the days after the ankle sprain--the reason for this is gravity pulling the blood downwards in the foot.
When to See a Doctor
If you do have significant symptoms following a sprained ankle, you should seek medical attention. Signs that should raise concern include:
Inability to walk on the ankle7
Symptoms that do not improve quickly or persist beyond a few days
Pain in the foot or above the ankle
Differentiating between a sprained ankle and an ankle fracture can be difficult, and sometimes an x-ray is needed.8 While moderate pain and swelling are common symptoms following a simple sprained ankle, symptoms such as inability to place weight on the leg or pain directly on the bone should raise concern. If you think you may have done more than sustained a sprained ankle, you should seek medical attention.
A high ankle sprain is a particular type of injury to the ligaments above the ankle. In a high ankle sprain, the ligaments above the joint are also injured. These ligaments, called the syndesmosis ligaments, connect the two shin bones (tibia and fibula), and may necessitate a longer course of rehabilitation.
Ankle Sprain Treatment
Treatment of sprained ankles is important because returning to normal activities in a timely manner is important for most patients. Treatment begins with standard R.I.C.E. (Rest, Ice, Compression, and Elevation) treatments, but should quickly progress to rehabilitation and strengthening.6 Only in unusual circumstances is surgery considered for treatment of an ankle sprain.