When Chris Peterson sprained his ankle playing football in high school, he brushed it off as a minor injury. His ankle hurt for a couple days, but no one suggested he see a doctor, and soon enough, it felt better. “I got back to playing as soon as I could,” said Dr. Peterson, now a physical therapist at Washington University in St. Louis. However, although his ankle didn’t hurt, it just wasn’t the same afterward.
“I’d step wrong, and my ankle just wasn’t there,” which often led to falls, he said.
Sprained ankles are among the most common musculoskeletal injuries. Official estimates are that two million people in the U.S. sprain their ankle every year, but the real number is likely much higher, as many people never seek care for their injury.
Although an ankle sprain may seem like a minor injury, suffering one leads to a much higher chance of doing it again. In a study of military cadets, those with a history of sprained ankles were 3.4 times more likely to sprain their ankle during the course of the study, compared with those with no history of sprained ankles. For an estimated 40 percent of people, a sprained ankle can lead to chronic ankle instability, characterized by repeated rolling of the ankle, a general feeling of wobbliness and instability, and occasional pain, tenderness or swelling.
If you’ve sprained your ankle in the past, that doesn’t mean that you are destined to go through life with an achy, wobbly joint, fearing the moment when it will give way. Experts recommend a number of exercises to strengthen the ankles, which in turn reduce the chances of sustaining a sprain, whether for the first time or the 10th.
Why many ankle injuries don’t fully heal
“The biggest reason people have recurrent ankle sprains is that they never do rehabilitation,” said Dr. Michael Fredericson, a sports physician at Stanford University.
The ankle is a complicated patchwork of bones and ligaments stitched together, connecting the tibia and fibula of the leg to the delicate bones of the foot. It has to do a lot of work, bearing the full weight of the body while also bending and flexing in many directions. It’s this versatility, along with a constant workload, that makes fully recovering from an ankle injury so difficult and critical, since it’s very easy to reinjure an ankle. “There’s not a lot of room for error, particularly if you do sports,” Dr. Fredericson said.
The key is exercise. In a recent meta-analysis of 14 randomized controlled trials, exercise-based interventions were more effective at reducing the risk of recurring sprains than usual care, which often consists of rest, ice, compression and elevation.
“We do know that exercise therapy works,” said Jente Wagemans, a graduate student at the University of Antwerp and the lead author of the study. “We know that it is effective for the prevention of a secondary injury.”
Even in the first few days after a sprain, it can help to move the ankle. Dr. Alysia Robichau, a sports physician at Houston Methodist Hospital, often recommends very light, non-weight-bearing activity, such as tracing the alphabet with the foot, in the days after a sprain. “That helps with gentle range of motion,” she said.
Slowly strengthening the ankle
Once the ligament has started healing, which happens in the first few weeks after a sprain, the next step is weight-bearing exercise. Like bones and muscles, Mr. Wagemans explained, ligaments become stronger when you apply increasing amounts of force.
Unlike bones, ankle ligaments need to be strengthened in multiple directions, because the joint is so mobile. One simple ankle-strengthening exercise is to loop a resistance band around the foot and attach it to something heavy, like a table leg. Then flex the foot forward, backward and sideways, aiming for three sets of 15 repetitions each.
If you are trying to prevent ankle injuries, these exercises should be done three to four times a week. If you are recovering from a recent ankle sprain, any exercises should be under the guidance of a physical therapist, who will tailor them to the injury.
The risk of nerve damage
Every time you step on an uneven surface or have to place your foot quickly, tiny nerves in your ankle automatically help it remain steady rather than rolling or twisting. Think of them as the lane-assist feature in some cars, which make tiny steering corrections to avoid drift, Dr. Peterson said, except the nerves bring your ankle back to a neutral position. One major cause of wobbly ankles is when sprains also damage these corrective nerves.
“Without that feedback system, you are more likely to roll your ankle again,” said Jeff Harvath, a physical therapist at Washington University in St. Louis.
Single-leg balancing to retrain nerves
If your ankle feels wobbly or unstable or has a habit of rolling, you need to retrain the nerves in that area. “It’s about teaching the muscles and the ligaments to coordinate in the right ways,” Dr. Robichau said.
One of the best ways to do this is a single-leg balance exercise. To start, balance on one leg, reaching out with your arms in different directions, aiming for one set of 20 repetitions. It’s important to use a lot of varied movements, such as reaching out for something with your hands, shifting your weight, closing your eyes or even standing on one leg while brushing your teeth. “The more real it seems, the more it transfers” to daily life, Dr. Peterson said.
Once you are comfortable with this, incorporate an element of instability by balancing on a couch cushion, foam balance pad or Bosu ball. For an additional challenge, add a light weight or medicine ball. Another variation is the standing leg star tap. Balance on one foot and reach the other foot out in straight line, forward, to the sides and backward, in a clockwise pattern, aiming for two sets of 15 repetitions.
Strong muscles to support your ankles
The muscles of your legs, ankles and feet also play an important role in ankle stability, which is why it’s important to strengthen them. Whenever your ankle joint gets pulled in the wrong direction, your ankle and calf muscles help pull it back. “We don’t want to rely on ligaments for everything,” Dr. Harvath said.
This includes the muscles of our lower legs, which tilt our foot in, out, up and down. Strengthening these muscles can help compensate for weaknesses in the ligaments of the ankle. Dr. Harvath recommended lunges onto an unstable surface, such as a couch cushion, foam balance pad or Bosu ball. He recommended two sets of 15 repetitions for each leg.
Another exercise for your calves and ankles is the standing heel raise, which can be done with a single leg or both legs. Stand with your feet shoulder-width apart. Simply rise to your tiptoes, then lower your heels to the ground. Aim for three sets of 10 repetitions.
If done regularly, these exercises can both prevent and help you recover from injury. As for Dr. Peterson, his ankle instability forced him to stop playing football and persisted for about 10 years. It was only when he went to school for physical therapy that he started his own ankle-strengthening exercise routine.
Today, although the ligament in his ankle is still damaged, he has been able to compensate and create the stability he needs. He does all of his favorite activities, such as running marathons and rock climbing, without worrying about his ankle rolling. For many of the patients he sees, regaining strength and stability in their ankles is a matter of learning what exercises to do. “It’s often very simple,” he said.
Rachel Fairbank is a freelance science writer based in Texas.