Overview
An ankle sprain occurs when the ligaments supporting the ankle are overstretched or torn, usually when the foot rolls inward (inversion injury), straining the lateral ligaments. It is one of the most common musculoskeletal injuries. Most sprains heal fully with appropriate management, though inadequate rehabilitation leads to chronic instability.
How common is it?
Ankle sprains are extremely common — approximately 300,000 occur in the UK each year. They account for about 3 to 5% of all A&E attendances and are particularly prevalent in athletes.
Causes and risk factors
Sudden uncontrolled inversion or eversion of the foot stresses the ankle ligaments beyond their tensile capacity, causing fibres to stretch or tear.
Common risk factors
- Running on uneven terrain
- Landing awkwardly from a jump
- Contact sports: football, basketball, netball
- Previous ankle sprain (single biggest risk factor for recurrence)
- Wearing high heels
- Muscle weakness or fatigue
- Poor proprioception (joint position sense)
Symptoms
- Immediate pain and tenderness over the lateral (outer) or medial (inner) ankle
- Swelling and bruising developing over hours
- Difficulty bearing weight (in moderate to severe sprains)
- Feeling of instability or 'giving way'
- Stiffness and reduced ankle movement
When to see a doctor
Seek urgent assessment for severe or worsening pain or swelling, inability to bear weight or walk more than a few steps, or symptoms that are not improving. A deformity, numbness, a cold or discoloured foot, or a crack heard at injury needs emergency assessment. A clinician should decide whether an X-ray is needed; do not try to rule out a fracture using a checklist yourself.
Diagnosis
Clinical examination assessing tenderness location, stability (anterior drawer test), and range of movement. X-ray if Ottawa criteria met. MRI for suspected ligament rupture or osteochondral injury in complex cases.
Treatments
PRICE protocol (first 48 to 72 hours)
Protection, Rest, Ice (15 to 20 minutes every 2 hours), Compression (tubigrip or wrap), Elevation above heart level. Reduces swelling and pain in the acute phase.
Early mobilisation and physiotherapy
Once acute pain allows, early movement and weight-bearing as tolerated produce faster, more complete recovery than immobilisation. Physiotherapy with proprioceptive and strength exercises prevents re-injury.
Functional bracing
Semi-rigid ankle brace during rehabilitation and return to sport. More effective than cast immobilisation for grade II and III sprains in terms of return to sport time.
Surgery
Reserved for complete ligament rupture in athletes who fail 3 to 6 months of rehabilitation and have persistent instability. Brostrom-Gould ligament reconstruction has excellent outcomes.
Self-care and lifestyle
- Complete the full rehabilitation course before returning to sport
- Use a prophylactic ankle brace for high-risk sports for at least 6 months after an ankle sprain
- Balance and proprioception training (wobble board) specifically reduces re-sprain risk
- Replace worn-down sports footwear
Prevention
Sprains cannot always be prevented. Return to activity gradually and follow any rehabilitation advice given for your injury.
Sources for targeted updates
Updated: 11 September 2026. Patient-facing assessment advice after an ankle injury. This update covers the named sections; a full review of the remaining guide is pending.