Ankle sprain
An injury to the ligaments of the ankle, most commonly the lateral (outer) ligaments. Sprains range from mild stretching of the ligament fibres to complete tears that may need prolonged treatment.
📊 Ankle sprains are one of the most common musculoskeletal injuries, affecting approximately 1 in 10,000 people per day in the UK. Up to 40% of patients go on to develop chronic ankle instability or persistent symptoms.
What is an ankle sprain?
The ankle is stabilised by three groups of ligaments. The lateral ligament complex on the outside of the ankle is by far the most commonly injured, accounting for around 85% of all ankle sprains. It consists of three ligaments - the anterior talofibular ligament (ATFL), the calcaneofibular ligament (CFL), and the posterior talofibular ligament (PTFL). Of these, the ATFL is the weakest and most frequently torn.
Sprains are usually caused by an inversion injury - the foot rolls inwards while the ankle is plantarflexed. This commonly happens when stepping off a kerb, landing awkwardly from a jump, or playing sports. Sprains are graded from Grade 1 (mild ligament stretching, no instability) through Grade 2 (partial ligament tear, mild laxity) to Grade 3 (complete ligament rupture, significant instability).
High ankle sprains, affecting the syndesmosis between the tibia and fibula, are a separate and more serious injury. They typically occur with external rotation of the foot and have a longer recovery time. A small but important group of patients who fail to recover well from an ankle sprain go on to develop chronic ankle instability, where the ankle gives way repeatedly. This can lead to ankle arthritis if left untreated.
Common mechanisms
- Inversion injury - foot rolls inwards (lateral ligament sprain, most common)
- Eversion injury - foot rolls outwards (deltoid ligament sprain, less common)
- High-energy twisting injury with external rotation (syndesmotic sprain)
- Sports involving jumping, cutting, or uneven surfaces
- Walking on uneven terrain
- Previous ankle sprain (significantly increases risk of recurrence)
Who is at risk? Risk factors include previous ankle sprain (the strongest predictor), participation in sports such as football, netball, basketball, and dance, high BMI, generalised joint laxity, and inadequate proprioception or neuromuscular control. Footwear without ankle support also contributes.
Symptoms
Symptoms typically begin at the time of injury and can vary depending on the severity:
- Sudden pain on the outside of the ankle at the time of injury
- Audible pop or tearing sensation (in higher-grade sprains)
- Rapid swelling and bruising around the ankle
- Difficulty or inability to weight-bear immediately after injury
- Tenderness over the affected ligaments
- Feeling of instability or the ankle giving way (particularly in chronic cases)
When to seek help: Seek medical assessment within 24-48 hours if you cannot bear weight on the ankle for at least 4 steps, if there is significant bony tenderness over the malleoli or midfoot, if there is severe deformity, or if symptoms do not improve substantially within 2 weeks. The Ottawa Ankle Rules guide the need for X-ray imaging.
How is it diagnosed?
Your foot and ankle specialist will take a detailed history and examine the foot. The following investigations may be arranged to confirm the diagnosis:
- Clinical examination - assessment of swelling, bruising, range of movement, and stability
- Ottawa Ankle Rules - guide the need for X-rays based on bony tenderness and ability to weight-bear
- Anterior drawer test and talar tilt test - assess ligament laxity (usually 1-2 weeks after injury when swelling settles)
- X-ray - to exclude fracture (around 15% of ankle injuries presenting to A&E have a fracture)
- MRI - reserved for persistent symptoms beyond 6-8 weeks, suspected syndesmotic injury, or chronic instability
Fractures and ligament injuries can co-exist, particularly avulsion fractures where the ligament pulls off a small fragment of bone. Suspected high ankle (syndesmotic) sprains warrant a different rehabilitation approach and prolonged recovery, so accurate diagnosis matters.
Treatment pathway
Treatment depends on the severity of the injury, your age, and your activity demands. Many injuries can be managed without surgery; others require surgical fixation.
PRICE / POLICE protocol
Protection, Optimal Loading, Ice, Compression, and Elevation. Modern guidance favours early protected weight-bearing over complete rest, as gentle loading promotes healing and recovery. Crutches or an ankle brace can be used for comfort.
Functional rehabilitation
A structured physiotherapy programme is the most important treatment. Early range-of-movement exercises, progressive strengthening of the peroneal muscles, and proprioception training (balance exercises) all reduce the risk of recurrence and chronic instability.
Progressive loading and return to sport
Gradual reintroduction of running, jumping, and sport-specific drills. Ankle bracing or taping during sport for the first 6-12 months reduces re-injury risk by around 50%.
Lateral ligament reconstruction (Brostrom-Gould)
For patients with persistent giving way despite 6 months of physiotherapy, surgical repair or reconstruction of the lateral ligaments is highly effective. The Brostrom-Gould procedure tightens and reinforces the torn ATFL and CFL using local tissue. Success rates exceed 85%.
Ligament reconstruction with tendon graft
For patients with very poor remaining ligament tissue, or those undergoing revision surgery, reconstruction using a tendon graft (autograft or allograft) is preferred. Recovery takes around 6-9 months.
Recovery
Recovery depends on the grade of injury. Grade 1 sprains usually settle within 2 weeks. Grade 3 sprains, with complete ligament rupture, may take 3 months or more to recover full function. Adequate rehabilitation is essential - the most common reason for chronic ankle instability is incomplete rehabilitation after the initial injury. Early functional treatment is now preferred over prolonged immobilisation in a cast.
- Grade 1 sprain recovery: 1-2 weeks
- Grade 2 sprain recovery: 3-6 weeks
- Grade 3 sprain recovery: 6-12 weeks
- Return to sport (after physiotherapy): 6-12 weeks
- Recovery from surgical reconstruction: 4-6 months
What results can I expect?
Around 60-70% of patients make a full recovery after a single ankle sprain with appropriate treatment. However, around 30-40% develop persistent symptoms, recurrent sprains, or chronic ankle instability. Risk factors for poor outcome include inadequate initial rehabilitation, early return to sport, and high-grade injuries.
In numbers
When can I…?
Typical activity timelines for this condition. These are approximate and vary considerably between patients. Always follow the specific guidance given by your surgeon and physiotherapist.
| Activity | Typical timeline | Notes |
|---|---|---|
| Bear weight | From day 1, as tolerated | Modern guidance (POLICE) favours early protected weight-bearing rather than complete rest.[2] |
| Use a brace | 1-2 weeks | A removable ankle brace or boot for comfort. Crutches if needed to walk comfortably.[1] |
| Drive | When able to brake safely | When you can perform an emergency stop without pain or hesitation. Often within 1-2 weeks for mild sprains.[4] |
| Start balance work | Within 1-2 weeks | Proprioception and peroneal strengthening exercises reduce the risk of future sprains and chronic instability.[1] |
| Return to running | 2-6 weeks | Light jogging once walking is comfortable and balance is recovered. Sport-specific drills before return to competition.[1] |
| Return to contact sport | 6-12 weeks | Depending on grade. Continue ankle bracing or taping for the first 6-12 months after a significant sprain.[1] |
Is this normal?
Common concerns from patients with this condition or recovering from treatment, and whether they are expected or worth mentioning to your team.
Preparing for surgery?
Read our step-by-step guide: what to expect before, during, and after your procedure.
Related injuries & conditions
Your questions, answered
Plain-English answers to the things people most often ask, grounded in published guidance. Tap a question to open it.
About thisWhat have I actually injured?
An ankle sprain is a stretch or tear of the ligaments on the outer side of the ankle, usually from the foot rolling inwards. Most are mild to moderate.
Bruising and swelling are common and do not by themselves mean anything is broken.
Your choiceDo I need an X-ray?
Not usually. Doctors use the Ottawa ankle rules to decide: an X-ray is needed mainly if there is bony tenderness in specific spots or you cannot take four steps.
Most sprains do not need imaging.
Getting backWhat is the best early treatment?
Early protected movement and a return to gentle loading work better than prolonged rest. Move and bear weight as pain allows, and physiotherapy helps for anything more than a minor sprain.
Long spells of complete immobilisation tend to slow recovery.
Getting backHow long does it take to heal?
Most ankle sprains settle over a few weeks. More severe ligament injuries can take a few months to feel fully reliable.
Swelling can linger after the pain has gone.
WellbeingWhy do some ankles stay weak afterwards?
A proportion of people, up to around four in ten, go on to have ongoing instability or repeated giving-way.
Balance and strengthening rehabilitation substantially reduces this, which is why finishing your exercises matters.
UrgentWhat needs urgent review?
Get seen if you cannot put any weight through the ankle, there is an obvious deformity, or the foot feels numb, cold or pale.
Seek urgent help for a hot, swollen calf or breathlessness, which can signal a clot.
References & further reading
- 1.British Orthopaedic Foot & Ankle Society: Ankle sprain and instability patient information
- 2.NICE CKS: Sprains and strains (clinical knowledge summary)
- 3.Ottawa Ankle Rules (decision tool for ankle injury imaging)
- 4.Royal College of Surgeons of England: Driving after surgery guidance
- 5.NHS: Sprained ankle
References are to UK clinical guidance and patient information from recognised organisations. This page is for general information and does not replace personalised advice from your own clinical team.