Ankle Sprain (Sprained Ankle)

What happens in an ankle sprain

The ankle is held together by ligaments, tough bands of tissue that connect bone to bone. About 85 in 100 sprains are lateral (inversion) sprains: the foot rolls inward and the ligaments on the outside of the ankle are stretched or torn. The anterior talofibular ligament (ATFL) is injured first, then the calcaneofibular ligament in more severe sprains.

Less common types (see also ligament sprains elsewhere in the body):

• Medial (eversion) sprain: the foot rolls outward, injuring the strong deltoid ligament on the inside. Often comes with a fracture.
• High ankle sprain (syndesmotic sprain): injury to the ligaments joining the two leg bones above the ankle, from twisting the foot outward. Recovery takes about twice as long.

Grades of ankle sprain

Symptoms

• pain on the outside of the ankle, worse when standing or walking
• swelling, usually within hours
• bruising that may spread to the foot and toes over a few days
• tenderness over the injured ligament, just in front of and below the outer ankle bone
• stiffness and reduced movement
• a feeling of instability in more severe sprains
• a pop or tearing sensation at the time of injury in some cases

Sprained ankle vs broken ankle

It can be hard to tell a bad sprain from a fracture: both cause pain, swelling and bruising. Doctors use the Ottawa ankle rules to decide who needs an X-ray. An ankle X-ray is needed if there is pain around the ankle bones and any of:

• tenderness along the back edge or tip of the outer ankle bone (lateral malleolus), over the lower 6 cm
• tenderness along the back edge or tip of the inner ankle bone (medial malleolus), over the lower 6 cm
• inability to bear weight for 4 steps both right after the injury and in the clinic

A foot X-ray is needed for tenderness at the base of the fifth metatarsal (outer midfoot) or the navicular (inner midfoot), or inability to take 4 steps. These rules safely rule out a fracture for most people. See ankle fracture.

Causes and risk factors

• landing awkwardly from a jump, stepping on another player's foot, or changing direction quickly in sports such as basketball, soccer and volleyball
• walking on uneven ground, curbs or stairs
• high heels or unsupportive shoes
• a previous ankle sprain, the strongest risk factor, especially without rehab. A sudden pop at the back of the heel is different: it suggests an Achilles tendon rupture
• weak ankle and hip muscles and poor balance

Diagnosis

A doctor will ask how the injury happened and examine the ankle for swelling, tenderness, stability and the Ottawa ankle rule points. Tests include:

• X-ray when the Ottawa rules are positive
• stress tests, such as the anterior drawer test, which are most accurate 4 to 5 days after injury when swelling has settled
• MRI if pain persists beyond 6 weeks, to look for cartilage damage (osteochondral lesions), tendon tears or a high ankle sprain

Treatment

Current guidelines favor short-term protection followed by early movement and exercise rather than long immobilization.

First 2 to 3 days

• Protect: reduce weight on the ankle as pain dictates, with crutches if needed.
• Elevate the ankle above heart level to limit swelling.
• Ice wrapped in a cloth for 10 to 20 minutes every 2 to 3 hours can ease pain. Do not put ice directly on skin.
• Compress with an elastic bandage or support, loose enough not to cause numbness.
• Pain relief: acetaminophen (paracetamol) is a good first choice. NSAIDs such as ibuprofen also work. Follow the label dose and avoid NSAIDs if you have kidney problems, stomach ulcers or heart failure.

Early movement and loading

• Start gentle range-of-motion exercises within a few days: trace the alphabet with your toes, and point and flex the foot.
• Walk as soon as pain allows. Walking early speeds recovery.
• Use a lace-up brace or semi-rigid ankle support for moderate sprains. This works better than a cast or crutches alone. Severe sprains may need a short period in a walking boot.

Rehabilitation

Exercise therapy is the most important part of treatment and reduces the risk of re-spraining:

• Strength: resistance band exercises in all directions, calf raises
• Balance (proprioception): standing on one leg, progressing to eyes closed and unstable surfaces, for at least 6 to 10 weeks
• Sport-specific drills: jogging, cutting, hopping and jumping before returning to sport

A physical therapist can guide this, especially after moderate or severe sprains.

Surgery

Surgery is rarely needed. It is considered for chronic instability that does not improve with rehab, some high ankle sprains, associated fractures, or cartilage and tendon injuries.

Recovery and return to sport

Return to sport when you can walk and jog without pain, hop on the injured leg, and balance on it as well as on the other side. Wearing a brace or tape for 6 to 12 months after returning to sport lowers the chance of another sprain.

Complications

• Chronic ankle instability: up to 1 in 3 people have ongoing giving way, pain or repeated sprains, often from incomplete rehab.
• Osteochondral lesions: damage to the cartilage and bone of the talus, causing deep pain and catching.
• Peroneal tendon injuries.
• Post-traumatic arthritis after repeated injuries.

Frequently asked questions

How long does a sprained ankle take to heal?

Mild sprains usually heal in 1 to 3 weeks and moderate sprains in 3 to 6 weeks. Severe sprains with complete tears can take 3 to 6 months. Ligament strength continues to improve for months, so balance exercises should continue after pain settles.

How can I tell if my ankle is sprained or broken?

You cannot always tell by looking. You likely need an X-ray if you could not take 4 steps after the injury or if pressing on the back edge or tip of either ankle bone, the outer edge of the midfoot or the inner midfoot is painful.

Should I walk on a sprained ankle?

Yes, as soon as pain allows. Early, protected walking with a brace or support speeds healing compared with long rest. Use crutches for the first few days if walking is too painful, and increase activity gradually.

What is the fastest way to heal a sprained ankle?

Protect and elevate it for the first 2 to 3 days, use ice and pain relief, then start gentle movement and walking early. A lace-up brace for moderate sprains and a structured balance and strengthening program give the fastest and most complete recovery.

Why does my ankle still hurt months after a sprain?

Ongoing pain or giving way months later can mean chronic ankle instability, a cartilage injury, a missed fracture, a tendon injury or a high ankle sprain. See a doctor or physical therapist. An MRI may be needed.