Fact sheet: Ankle sprain

Sometimes one awkward step is all it takes for your foot to twist sideways. Most of the time this does not cause any damage, but sometimes your ankle may swell up and hurt. If you cannot put weight on your foot, or if you have difficulty walking, it is likely you have sprained your ankle. A broken ankle is much less common: of the people who go to the hospital because of a painful ankle, only about 15% turn out to have broken it.

Ankle sprains are some of the most common injuries. A sprained ankle can mean many things, ranging from a harmless stretched ligament to serious ligament tears, which will limit mobility for a long time. Ankle sprains generally heal well, but sometimes a little patience is needed. The ankle, or ankle joint, can lose its stability after the injury, so that it might be necessary to do exercises to improve its strength.

In this fact sheet you can find out what researchers in physiotherapy and sports medicine have learned about ankle sprains: below you can read more about simple strains, first aid, and strength exercises, as well as when surgery might be necessary.

What exactly is an ankle sprain?

In a sprained ankle, one or more ligaments of the ankle joint are injured. The ligaments in the ankle joint are white, tough, elastic bands of connective tissue that connect one bone to the other. Because the ankle joint is made up of many bones, there are also a lot of ligaments to stabilize and strengthen it.

With the help of the ankle we can move our foot upwards and downwards. It is easier to twist the foot inwards than outwards. This means that if we take an awkward step or land badly on our foot and twist our ankle, our foot is twisted inwards.

The ligaments most commonly damaged when we twist our ankle are the ones that run along the outside of the ankle. They are called outer or lateral ligaments. The ligaments on the inside of the ankle (medial ligaments) are affected less often. Some people have very weak ligaments and therefore tend to sprain their ankles more easily. Ankle sprains are also more common in people with high arches, slower muscle reaction time or muscle weakness. Athletes also carry a higher risk: one quarter of all sports injuries are ruptures of the outer ligaments.

When the ankle is twisted, the ligaments are overstretched, which, in the worst case, could cause a ligament to tear. Because blood vessels tear as well, the front and side of the ankle become swollen. Generally speaking, the worse the swelling, the more severe the injury is. If you can take steps and walk directly after having twisted your foot, you have most likely not broken anything. But even a minor ankle sprain can be painful. If the ligaments have only been slightly stretched, you can usually move your foot again normally after a few days.

There are several grades of ankle sprains:

• Grade I sprain: This is the most common form, which causes the least harm. The ligaments are overstretched, but not torn. It is unlikely that the ankle becomes unstable.
• Grade II sprain: This injury is more severe and more painful, and the ligaments are partly torn. However, the ankle remains stable.
• Grade III sprain: The ligaments are torn and the ankle is unstable.

First aid in sprained ankles: what is important?

A sprained ankle swells up quickly, and starts to hurt just as quickly. To immediately treat pain and swelling you can relieve your foot by following the R.I.C.E. treatment plan: rest, ice, compression and elevation. This means lying down, keeping your foot elevated, cooling the ankle and wrapping it in an elastic bandage to put mild pressure on it.

If the ankle is not severely injured, this will be enough. If the symptoms do not get considerably better after a few days, a ligament might be torn. It usually takes four to seven days before a doctor can diagnose a ligament rupture with certainty. If you immediately think that it might be a more severe ankle sprain, a doctor can find out how serious it is. The ankle can be X-rayed to see whether a bone is broken. If the ankle is broken, you are likely unable to walk, and it already hurts when the doctor puts pressure on the affected bone.

When is a bandage enough, and when is physiotherapy a good idea?

A grade I ankle sprain will usually start to get better after a few days: a bandage or ankle brace and resting your foot will be enough. After a while you can carefully start putting weight on your foot again. If you have only slightly sprained your ankle you can walk normally again after about one week. It might not be necessary to continue cooling the foot after the first day, because the pain-relieving effect will start to decrease. But you can continue to cool it, if you feel that cooling helps.

If the ligaments are torn, it will take weeks before you can put your full weight on your again. The ligaments need to rest to be able to grow together again, so you will need to wear an ankle brace for several weeks. You will be shown some strength training exercises you can do in the meantime, in order to strengthen the foot before starting to walk again. In these exercises, the foot is stretched and bent in different directions. Usually a physiotherapist will show you how to do these exercises and will follow-up with you on your way to recovery. Decisions about when the exercises can be started are made on an individual basis, but it is often possible after about two or three weeks following the injury.

By doing these mobilization exercises you will be back on your feet again faster than if you keep your foot immobilized in an ankle brace for a longer period of time. The exercises can reduce swelling and pain. But scientific research has shown that, as far as the long-term stability of the ankle joint is concerned, it will not make a difference whether you start doing exercises early or keep your foot immobilized for a longer period.

Sometimes physiotherapists offer ultrasound or electrotherapy in addition to conventional treatments. The sound waves or electric stimuli are meant to speed up the healing process. While trials have not shown any added benefit when these treatments are done in addition to the more conservative therapy described above, neither have the trials shown that the treatments do any harm.

How can the pain be relieved?

Resting, cooling, a compression bandage and keeping the foot elevated can provide some relief directly after the injury. If this is not enough, painkillers can help. A group of painkillers called non-steroidal anti-inflammatory drugs (NSAIDs), available in the form of ointments or tablets, can provide short-term relief of the pain and swelling. Examples of NSAIDs include ASA, ibuprofen, diclofenac and acetaminophen (paracetamol). However, the effect of these drugs has only been well studied in the first two weeks of treatment.

Painkillers can have adverse effects as well. The longer you take them and the higher the dose, the more likely you are to experience adverse effects. For example, NSAIDs can damage the lining of the stomach if they are taken over a longer period of time. For a sprained ankle you will only need these medications for a short time, however. If the pain is so strong that it cannot be relieved effectively by NSAIDs, it may be a good idea to talk to your doctor. If you take NSAIDs longer-term, the doctor can prescribe additional tablets to protect the lining of your stomach.

There are also creams or ointments containing herbal or homeopathic ingredients. But these have not been tested sufficiently in conclusive trials so that it is not yet know whether they really help.

When can surgery help?

Torn ligaments can be sewn back together surgically. However, in most cases, surgery will not lead to people being able to walk again faster than if they have functional treatment with early mobilization exercises. Like any operation, this one is also associated with certain risks (for example, nerve damage or adverse effects of general anesthesia). People who do competitive sports sometimes choose surgical interventions and hope that surgery will help them to recover completely more quickly. But there is no scientific evidence that confirms this assumption. On the contrary: research suggests that people who have functional treatment are able to do sports again more quickly than those who undergo surgery. Research to date has shown that early mobilization works best the sooner you start putting weight on the ankle joint. In the long term, however, it seems that ligaments that are operated on are more stable than those only treated functionally.

If six months after the ankle sprain the ankle joint is still unstable, you might be offered the option of surgery. Yet it has not been proven that operations are always more helpful in chronic instability than specific exercises. You can read more about the research results here.

If you decide to have surgery for ankle instability, it is important to start with mobilization and coordination exercises soon afterwards. This does not necessarily have a long-term benefit, but you are more likely to be able to take up your normal activities faster than if you wear an ankle brace and rest it for a longer time.

What is chronic ankle instability and how long does it take for the ankle joint to be fully functional again?

Most ankle sprains without ligament tears are, for the most part, healed after two weeks: Even if you are not able to put your full weight on the foot, most of the time it hardly hurts anymore. But sometimes it takes two to three years before the foot works normally again. About 1 to 2 out of 10 people with a severe ankle sprain might develop chronic ankle instability. That means that the joint is giving way too easily: it is unstable. If you have chronic ankle instability you are more likely to twist your foot again and sprain your ankle.

One out of three people with a sprained ankle will hurt their ankle joint again in the years following the initial sprain. This is particularly a problem for people who put a lot of strain on their joints – when playing soccer or basketball, for example.

Chronic ankle instability and frequent twisting and spraining can also increase wear and tear on joint cartilage. Cartilage is a smooth tissue that covers the joints with a protective layer. If the cartilage is damaged too severely, it may lead to osteoarthritis. All in all, it is very important in the long run to take good care of your joints.

Strength and coordination exercises can improve chronic instability. However, these exercises typically have to be performed for weeks or even months to have a benefit. Some exercises can include training on a balance board. This involves standing on one leg on a board that easily tilts sideways, even if you only move slightly. The exercises involve trying to counteract the tilting movement without losing your balance. This forces the foot to level different strains and movements without the joint giving in. It is possible that chronic instability can be reduced by improving your balance and strengthening your muscles and ligaments with these kinds of exercises.

How else can I strengthen my ankles and prevent sprains?

Some people wear bandages or ankle braces when they do sports. Supports, such as braces or bandages, have been shown to prevent at least some sports injuries. There is no scientific proof however that special socks or high-top shoes can prevent sprains.

But even if you have chronic ankle instability: Ankle sprains are generally not serious injuries. Most people who are very active – and certainly almost all people who do sports – will sprain their ankle at some point in their lives. The body is well equipped for coping with and healing stretches and tears. A bandage, rest and patience will most likely be enough to recover. The most important thing is to avoid immobilizing your joint for a long time. You will be able to walk again more quickly if you make sure to strengthen your ankle joint as soon as possible.


Author: German Institute for Quality and Efficiency in Health Care (IQWiG)

© IQWiG (Institute for Quality and Efficiency in Health Care)