Ankle sprains and ankle instability

What happens in a sprain

When the foot rolls under the leg, the ligaments on the outside of the ankle stretch or tear. Sprains are graded by how much damage there is: a mild stretch, a partial tear, or a complete tear of one or more ligaments. Swelling, bruising, pain on walking and tenderness over the ligaments are typical.^[1]

Ankle sprains are among the most common injuries in sport, but they happen just as easily on a curb or a stair.

Is it broken?

The Ottawa ankle rules, a short set of checks for tenderness over specific spots on the ankle and midfoot and the ability to take four steps, are very good at ruling out a fracture, and using them avoids unnecessary X-rays.^[4] When the rules suggest a fracture might be present, we take X-rays in the office the same day. Our article sprain or fracture? explains the signs.

Treatment for a new sprain

• Protect, then move. A brace or support for a short period, relative rest and ice for comfort, anti-inflammatory medicine if it suits you, then an early return to walking as pain allows. Early mobilization works better than keeping the ankle still for ordinary sprains.^[2,3]
• Exercise therapy. A structured program of range of motion, strengthening and balance training speeds recovery and reduces re-injury.^[3]
• Return to sport is based on function (strength, balance, hopping and cutting without pain) rather than the calendar. For athletes we build that plan with you; see sports medicine and our guide to recovering from a sprained ankle.

Common questions

Should I keep weight off it?

Only briefly, if it is very painful. For ordinary sprains, early movement and walking as pain allows lead to better recovery than keeping the ankle still, and anti-inflammatory medicine helps with pain and swelling for those who can take it.^[2] If you can’t take four steps, get it checked for a fracture first.^[4]

Should I wear a brace when I go back to sport?

For many people, yes. There is strong evidence that bracing, and moderate evidence that balance and coordination training, lower the risk of spraining the ankle again.^[2] We help you choose a brace that suits your sport.

How long will it take to recover?

Rehabilitation may take just two weeks for a minor sprain, or six to twelve weeks for a more severe one. Returning to sport before the ankle is fully rehabilitated is the most common reason sprains turn into chronic instability, so return is based on what the ankle can do, not the number of days.^[1]

An ankle that keeps giving way

Some people are left with an ankle that feels loose, gives way on uneven ground or keeps spraining. This is chronic ankle instability, and an international consensus of ankle specialists counts it among the long-term consequences of sprains, along with less activity and earlier ankle arthritis.^[5] A targeted rehabilitation program and bracing help many people.^[2] When the ligaments are too stretched for exercise to compensate, the ligaments can be repaired or reconstructed.

Other injuries that mimic a sprain

A few injuries hide behind a “bad sprain”: fractures of the fifth metatarsal or the ankle, a tear of the peroneal tendons on the outside of the ankle, a cartilage injury to the talus, and a high ankle sprain involving the ligaments between the shin bones. Pain that isn’t settling after several weeks deserves a careful re-examination and, sometimes, imaging.^[1] See cartilage injuries and fractures and trauma.

When to seek care