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What is an ankle sprain?

An ankle sprain occurs when ligaments that connect the bones in the foot, ankle, and lower leg are stretched or torn.

An inversion injury, the most common cause of ankle sprains, occurs when the ankle rolls outward and the foot turns inward. It results in stretching and tearing of the ligaments on the outside of the ankle. In a "high" ankle sprain, a less common type of inversion injury, the ligaments at the top and outside of the ankle are also torn, increasing the sprain's severity and healing time.

See an illustration of an ankle sprain .

While common, ankle sprains are not always minor injuries. About 25% of people who sprain their ankles have resulting long-term joint pain and weakness. ¹

What causes ankle sprains?

An ankles sprain often happens when you make a rapid shifting movement with your foot planted, for example, when playing soccer or when tackled in football.

Most commonly, the ankle rolls outward and the foot turns inward in what is called an inversion injury . This results in stretching and tearing of the ligaments on the outside of the ankle.
Less often, the ankle rolls inward and the foot outward in an eversion injury, damaging the ligaments on the inside of the ankle.

Injury to the ligaments varies in severity, and ankle sprains are graded accordingly.

• Grade I is stretching or slight tearing of the ligament with mild tenderness, swelling, and stiffness. It is usually possible to walk with minimal pain.
• Grade II is a larger but incomplete tear with moderate pain, swelling, and bruising. The damaged areas are tender to the touch, and walking is painful.
• Grade III is a complete tear of the affected ligament or ligaments with severe swelling and bruising. Walking is usually not possible because the ankle gives out and there is intense pain, although initial pain may quickly subside.
  
  See an illustration of a grade III ankle sprain .
  

What are the symptoms of an ankle sprain?

You usually feel immediate pain at the site of the tear. Often the ankle starts to swell immediately and bruising may also develop. The affected area is usually tender to touch.

In a mild sprain, swelling usually goes down within a few days.

If moderate or severe sprains do not heal correctly, your ankle joint may become prone to reinjury. Reinjury often occurs with even a slight trauma, such as stepping off a curb. People whose ankles are unstable and easily resprained often have persistent pain and swelling.

The severity of your symptoms usually depends on the how much tearing of ligaments has occurred. In more severe sprains, you are often unable to walk or even put weight on your foot, and your ankle may feel unstable. You usually have extreme pain at first that sometimes subsides within an hour. Some people hear and/or feel a tearing sensation and a pop or a snap.

If a sprain does not heal correctly, your ankle joint may become prone to reinjury. This often occurs with even a slight trauma, such as stepping off a curb or walking on uneven pavement. Some people complain of persistent pain and swelling.

How will my doctor diagnose an ankle sprain?            

Your doctor will ask you how the injury occurred, ask about any prior injuries, and examine your ankle, lower leg, and even your knee to see whether additional injury occurred.

If a sprain is mild, X-rays may not be needed. In more severe sprains, X-rays are usually taken, because it is possible to break a bone in the ankle or the foot at the same time a sprain occurs.

X-rays are usually taken in children because of potential injury to the bone's growth plate and possible disruption of normal growth.

How is an ankle sprain treated?

Initial treatment for ankle sprain is summarized as the PRINCE approach (others only use RICE approach):

• Protection.
  Use a protective brace, such as an air stirrup or another form of ankle support, along with a compression wrap, such as an elastic ACE bandage, for the first 24 to 36 hours.
• Rest.
  Use crutches until walking is not painful without them.
• Ice.
  For at least the first 24 to 72 hours or until swelling goes down, apply ice pack for 10 to 20 minutes every 1 to 2 hours during the day. After 48 hours, contrast baths, which alternate cold and warm water, are recommended.
• NSAIDs.
  Nonsteroidal anti-inflammatory drugs (NSAIDs) should be taken as directed—not only when you have pain—around the clock for the first couple of days.
• Compression.
  An elastic compression wrap, such as an ACE bandage, will help decrease swelling and should be worn for the first 24 to 36 hours. Compression wraps do not offer protection; a protective brace should also be worn if you try to bear weight on your injured ankle.
• Elevation.
  Raise your ankle above the level of your heart for 2 to 3 hours a day if possible to decrease swelling and bruising.

Proper treatment and rehabilitation exercises are critical for ankle sprains. If ankle sprains do not heal correctly, the joint may become unstable, resulting in a weakened and easily reinjured ankle. Taping or a brace worn during vigorous exercise may decrease the risk of reinjury.

Surgery to repair torn ligaments may be considered when there is a severe ligament tear (or tears) or if the ankle remains unstable after rehabilitation. Surgery is also a consideration if you have broken a bone.

What kind of rehabilitation program should I follow?

Rehabilitation exercises begin right after the injury with walking or bearing weight while using crutches if you can do so without too much pain. You can also begin range-of-motion exercises while you have ice on your ankle. These exercises are easily done by tracing the alphabet with your toe, which encourages ankle movement in all directions.

About 48 hours after the injury, you can begin contrast baths, alternating warm and cold soaks. Further rehabilitation—including stretching, strength training, and balance exercises over the next several weeks to months—is critical to ensure that the ankle heals completely and reinjury does not occur.

When to Call a Doctor            

See your health professional immediately if your foot or lower leg is bent at an abnormal angle.

You should see your health professional after an ankle sprain if you:

• Heard a "pop" when you sprained it.
• Have moderate or severe pain or severe swelling or bruising.
• Are unable to walk or put weight on your affected foot or your ankle feels unstable.
• Have any numbness or tingling that lasts after the initial injury.

If swelling and bruising last more than 2 weeks, contact your health professional.

If your pain is mild and you are able to put some weight on your foot, you may follow the recommendations in the Treatment Overview and Home Treatment sections of this topic. Initial treatment and rehabilitation exercises ensure that your ankle heals properly. If treatment recommendations are not followed, your ankle may remain weak and unstable.

Exams and Tests

Your doctor will ask you how the ankle sprain occurred and ask about any prior injuries.

Next, your doctor will examine your foot, ankle, lower leg, and even your knee to see if additional injury occurred. He or she may ask you to move your foot up and down and to take a few steps if possible. Your doctor will then carefully try moving your foot and ankle to see if the ligaments are intact.

If your sprain is mild, an X-ray may not be taken. If your sprain is more severe, you will need X-rays to evaluate any ligament tears and because it is possible to break a bone in the ankle or the foot at the same time a sprain occurs.

X-rays are usually taken in children because of potential injury to the bone's growth plate and possible disruption of normal growth.

Home Treatment            

Rehabilitation exercises for an ankle sprain can be done at home to promote proper healing and prevent chronic pain and instability. When rehabilitation exercises are not followed after a sprain, the ankle can become weak and unstable. About 25% of people who sprain their ankles have resulting long-term joint pain and weakness.¹

About 48 hours after the injury, some experts recommend beginning contrast baths to help decrease inflammation and swelling. To take a contrast bath, submerge your ankle in a bucket of ice-cold water (as cold as can be tolerated) for 30 seconds. Then, move your ankle into a second bucket filled with water that is as warm as can be tolerated, around 104F(40C), for 30 seconds. The soaks are alternated for a total of about 5 minutes, with the first and last soak in cold water. Ideally, these baths are repeated 3 times a day. Contrast baths can be continued at least daily for up to 2 weeks, although if swelling and bruising last this long, you should consult your doctor.

In the case of minor sprain, rehabilitation exercises begin soon after the injury with walking. For more painful and severe sprains, you may not be able to walk, although you might be able to bear weight while using crutches and a protective brace, such as an air stirrup or other form of ankle support. If pain is severe, use crutches until your doctor tells you that you can begin to bear weight. In general if your pain is bearable, you should try to walk or bear some weight while using crutches and a protective brace, because these activities promote healing.

Ankle sprains take an average of 6 weeks to heal but can take can up to 4 months, depending on their severity. An ankle brace, air stirrup, or other form of ankle support should be worn during this time to protect the ligaments. After the ankle is healed, wearing an ankle brace or taping the ankle can prevent reinjury.

Stretching exercises should be continued on a daily basis and especially before and after physical activities to prevent reinjury. Even after your ankle feels better, continue with muscle-strengthening exercises and balance and control exercises several times a week to keep your ankles strong.

Rehabilitation exercises may vary according to your doctor's or physical therapist's preferences. Following are some examples of typical rehabilitation exercises.

Range-of-motion exercises

Begin range-of-motion exercises right after your injury while you have ice on your ankle. Perform a set of exercises by repeating them 10 to 30 times. Do each set 3 to 5 times a day.

Try the following simple range-of-motion exercises :

• Trace the alphabet with your toe, encouraging ankle movement in all directions.
• Sit in a chair with your foot flat on the floor. Slowly move your knee side to side while keeping your foot pressed flat.

Towel curls . While sitting, place a hand towel on a smooth floor, such as wood or tile. While keeping your heel on the ground, curl you toes and grab the towel with your toes to scrunch the towel. Let go, and continue scrunching up the entire length of the towel. When you reach the end of the towel, reverse the action by grabbing the towel with your toes, scrunching it, and pushing it away from you. Repeat, until you have pushed the entire length of the towel away from you.

Stretching exercises

About 48 to 72 hours after your injury, start exercises to stretch your Achilles tendon, which connects the calf muscles on the back of the lower leg to the bone at the base of the heel.

Towel stretch . If you cannot stand, sit with your knee straight and a towel looped around the ball of your foot. Gently and slowly pull back on the towel for about 15 seconds until you feel your calf stretch. In moderate to severe ankle sprains, at first it may to painful to pull your toes far enough to feel a stretch in your calf. Use caution and let pain be your guide. A little pain is normal, but you should not feel moderate to severe pain. Repeat this exercise about 15 to 20 repetitions daily for about a week. Then, make Achilles stretches part of your daily routine to maintain flexibility.

Calf stretch . If you are able to stand, you can do this exercise by facing a wall with hands at shoulder level on wall. Place your injured foot behind the other with the toes pointing forward. Keep you heels down and your back leg straight. Slowly bend your front knee until you feel the calf stretch in the back leg. Repeat as above.

Strengthening exercises

Once you can bear weight without increased pain or swelling, begin muscle-strengthening exercises. These exercises should be held for 3 to 5 seconds. Do 15 to 20 repetitions once or twice daily for 2 to 4 weeks, depending on the severity of your injury.

Start by sitting with your foot flat on the floor and pushing it outward against an immovable object such as a wall or heavy furniture. After you feel comfortable with this, try using rubber tubing looped around the outside of your feet for resistance.

While still sitting, put your feet together flat on the floor. Press your injured foot inward against your other foot.

Next, place the heel of your other foot on top of the injured one. Push down with the top heel while trying to push up with your injured foot.

Balance and control exercises

When you are able to stand without pain, you can begin balance and control exercises. One of the easiest ways to increase your balance and control is to stand on just your injured foot while holding your arms out to your sides with your eyes open. When you can do this for 60 seconds, try adding the advanced moves in the next level.

Stand on your injured foot only and hold your arms:

• Across your chest with your eyes open.
• Out to the side and close your eyes.
• Across your chest and close your eyes.

Do these exercises 6 times for 60 seconds once a day.

For more information on exercising to strengthen your ankle and prevent reinjury, see:

Rehabilitation exercises for ankle sprain.

References

Rakel RE (2002). Orthopedics. In Textbook of Family Practice, 6th ed., 891–950. Philadelphia: W.B. Saunders