Ankles that keep rolling: chronic ankle instability

You sprained your ankle last year, or five years ago. Now it rolls on a curb, a tree root or a quick sideways step. If that sounds familiar, you may have chronic ankle instability. It’s common, it can be treated, and it deserves more than a brace and crossed fingers.

What “giving way” really means

Chronic ankle instability is a recurring giving way of the outer side of the ankle, often after repeated sprains. Typical signs:

• the ankle turning again and again, especially on uneven ground or during sport
• ongoing discomfort and swelling
• pain or tenderness
• an ankle that feels wobbly or unstable^[1]

The most common risk factor for a sprain is a previous sprain.^[2] Each new sprain weakens or stretches the ligaments further, making the ankle less stable.^[1]

Two kinds of instability

Specialists describe two types. Instability most likely comes from a mix of both.^[2]

Mechanical instability is a problem with the joint itself. The ligaments may be too loose, the joint may move abnormally, the joint lining may be irritated, or the joint may show wear.^[2]

Functional instability is a problem with control. It comes from shortfalls in proprioception, your sense of where your foot is, and in neuromuscular control, the quick muscle responses that catch the ankle as it starts to roll.^[2]

Exercise works on control. It isn’t meant to tighten a ligament that healed loose, which is why some ankles eventually need more.

How common is it?

Chronic instability develops in about 10% to 20% of people after an acute ankle sprain.^[6]

In a review of studies following people after a first sprain, the share who felt their ankle was unstable fell from about 38% at three months to 16% at six months and 8% at a year. About 16% had sprained the ankle again within a year.^[7] The authors suggest that, after a first sprain, a longer period of non-surgical treatment may be warranted before surgery.^[7]

Still, repeated sprains can lead to long-term ankle pain, arthritis and instability.^[8]

How we assess an unstable ankle

We start with your story: how you hurt the ankle and how often it gives way. Then we examine it for tender spots, swelling and signs of instability. X-rays or other imaging may be used to look further.^[1] We have X-ray and ultrasound at the practice.

A sprain can come with injuries to nearby cartilage and tendons, so lingering pain isn’t always instability alone.^[8] See peroneal tendon problems and cartilage injuries.

What helps: rebuild control first

Treatment starts without surgery.^[6] It may include physical therapy for strength and balance, a brace for support, and anti-inflammatory medicine for pain and inflammation.^[1] An evidence-based guideline prefers supervised, exercise-based programs over passive treatments.^[3]

Balance training. Poor balance often leads to repeat sprains and instability.^[8] In a review of 15 randomized trials in people with chronic instability, balance training improved function, instability and dynamic balance more than regular exercise did.^[4] An older Cochrane review found that neuromuscular training appears to help in the short term; whether that lasts is unknown.^[6] Good programs get harder as you improve:

• from a steady floor to a cushion or wobble board
• from eyes open to eyes closed
• from standing still to reaching, catching and hopping
• from slow, careful moves to the speed of your sport

Strength. Resistance exercises and toe raises strengthen the muscles and tendons that help steady the ankle.^[8] In that review of 15 trials, balance and strength training showed no clear difference for instability or balance; balance training did better for function.^[4]

Braces and tape: a seatbelt, not the engine. There is strong evidence that bracing helps prevent another ankle sprain, and moderate evidence for neuromuscular training.^[5]

In a network meta-analysis of randomized trials in people with ankle instability, taping, bracing and insoles were no better than no treatment at improving dynamic balance. The authors concluded that, on their own, they don’t appear to be a viable main treatment.^[9] That’s why a brace works alongside the exercises, not instead of them. Our sports medicine team builds that plan around your sport. See also ankle sprains and instability.

When surgery is considered

Surgery is reserved for ankles that stay unstable and painful after months of thorough, exercise-based rehabilitation, particularly when the ligaments are loose.^[3,8,6] It usually means repairing or reconstructing the damaged ligaments.^[1] Our colleagues at the Center for Lower Extremity Surgery explain chronic ankle instability (external site) and ankle ligament reconstruction (external site).

Common questions

Will it get better with time?

It might. In studies of people after a first sprain, pain and the feeling of instability kept easing for up to a year.^[7] But waiting while the ankle keeps rolling isn’t a plan, because each sprain can leave the ligaments weaker.^[1]

Do I have to wear a brace forever?

Not necessarily. A brace supports the ankle and helps prevent more sprains while you rebuild balance and strength.^[1] How long you need it depends on your sport and your ankle.

When to see a podiatrist