Why Do I Keep Spraining the Same Ankle?
If the same ankle sprains again and again, the usual reason is chronic ankle instability. The ligaments on the outer side of the ankle stretch or tear. If they never fully heal, the joint stays loose. Your balance reflexes also get weaker, so the ankle gives way more easily. A standing alignment scan can show whether your foot shape or leg alignment is adding extra strain.
Key takeaways
- Chronic ankle instability means the ankle keeps giving way after an earlier sprain.
- The main causes are loose ligaments and poor proprioception (your body's sense of joint position).
- Your foot shape and overall leg alignment can make another injury more likely.
- Standing, weight-bearing scans show alignment problems that lying-down scans can miss.
- A proper diagnosis guides the right rehabilitation or referral to a specialist.
What is chronic ankle instability?
Chronic ankle instability is a condition where the ankle gives way again and again. This happens most on uneven ground or during activity. It usually starts after one or more ankle sprains that did not fully recover.
When you twist your ankle, the outer (lateral) ligaments stretch or partly tear. The one most often affected is the anterior talofibular ligament, often shortened to ATFL. If this ligament heals in a lengthened position, the joint becomes mechanically loose. At the same time, the nerve endings in and around the ligament are damaged. This weakens your proprioception. That is your body's built-in sense of where the joint sits in space.
Without good proprioception, your muscles react too slowly to protect the ankle when the ground shifts under you. The result is a frustrating cycle: a sprain, partial recovery, then another sprain.
How do you know if your ankle is unstable?
The main sign is the ankle giving way. But there are several other clues to look for.
The ankle rolls inward without warning, especially on uneven surfaces or when you change direction.
Puffiness around the outer ankle that comes and goes, often after walking or sport.
The ankle feels wobbly, or you feel you cannot trust it, especially on stairs or slopes.
A dull ache along the outer ankle that never quite settles, even months after the last sprain.
If you also find it hard to balance on the affected foot with your eyes closed, that is a strong sign that proprioception has been affected.
What causes an ankle to keep spraining?
The first sprain is the trigger. But several factors explain why some ankles recover fully and others do not.
The most common reason is going back to activity before the ligaments and balance reflexes have fully recovered.
A high-arched (cavus) foot naturally tilts the heel inward (hindfoot varus). This puts extra load on the outer ligaments.
The way your knee, hip and pelvis line up affects how force travels through your ankle. A tilt higher up can overload one side.
The peroneal muscles run along the outer side of the leg and act as dynamic stabilisers. Weakness here leaves the ankle exposed. This can also lead to peroneal tendonitis.
People with hypermobility syndrome have naturally more flexible joints. This extra range of movement can mean the lateral ligaments give less passive support. That makes repeated sprains more likely.
How does standing imaging help with ankle instability?
Standing, weight-bearing imaging captures your ankle, foot and whole leg under real loading conditions. This is the only way to see how your bones and joints line up while gravity and your muscles are doing their normal job.
An EOS scan images you from head to toe while you stand. It shows your hindfoot angle, your arch height, and how your ankle, knee and hip stack above each other. Small tilts or rotations that drive repeated sprains become visible. The scan uses about 90% less radiation than a standard X-ray, around ten times less.
A standard X-ray or CT scan is usually taken lying down. In that position, your muscles relax, your arch may flatten differently, and gravity no longer loads the joint. Alignment problems that only show up when you are upright and bearing weight can be completely hidden.
A gait analysis can add more detail about how you move. But ScanAlign standing EOS imaging gives the structural picture that everything else rests on. It shows the full chain from your foot through your knee to your hip. This helps your clinician understand whether an alignment issue higher up is adding to your ankle problem.
When MRI is more useful: EOS is excellent at showing bones, joints and alignment. If your specialist needs to look in detail at the ligaments, tendons, cartilage or other soft tissues around the ankle, MRI is usually the better tool. The two scans work well together.
How do you strengthen a weak ankle after a sprain?
Rehabilitation is the foundation of managing chronic ankle instability. ScanAlign is a diagnostic imaging clinic, not a treatment provider, so the guidance below is general. Your physiotherapist or specialist will shape a programme around your findings.
Standing on one leg, wobble boards and balance drills with your eyes closed retrain the nerve pathways that protect the joint.
Resistance-band exercises for the muscles on the outer side of your lower leg build the ankle's active defence against rolling.
An ankle brace or sports tape can give outside support during activity while your strength and balance catch up.
If imaging shows a structural factor such as hindfoot varus or a cavus foot, an orthotist may recommend a corrective insole.
Getting a clear picture of the underlying structure first helps make sure your rehabilitation targets the right problem, rather than just treating the symptoms.
So before you start treatment, or change the one you are on, it is worth getting a detailed diagnosis. Knowing whether the cause sits in the pelvis, the legs or the spine changes what will actually help.
Wondering whether your ankle alignment is part of the problem? A short video call with our team can help you decide if a standing scan in London is the right next step.
Book a free video consultationFrequently asked questions about chronic ankle instability
After a sprain, the outer ligaments may heal in a stretched position. This leaves the joint mechanically loose. At the same time, the nerve endings that help your brain sense the joint's position are damaged. Together, these two factors mean the ankle cannot react quickly enough to stop another roll.
They are closely linked. Chronic ankle instability is the underlying condition. Recurrent ankle sprains are the events it causes. Not everyone with instability sprains often. Some people simply feel the ankle is loose or unreliable without a full roll.
Mild instability can improve with time and normal activity. However, research suggests that without targeted balance and strength work, many people go on to develop chronic problems. A structured rehabilitation programme significantly reduces the chance of injuring the ankle again.
An EOS scan captures your whole lower limb in a single standing image, with about 90% less radiation than a standard X-ray, around ten times less. Because you are upright and bearing weight, it shows alignment details that a lying-down X-ray can miss, such as hindfoot tilt and arch height under load.
No. ScanAlign is a private, self-pay clinic. You can book directly without a referral. A free video consultation is the first step, so you can talk through your situation before you commit.
The price for patients travelling from abroad is confirmed during the free video consultation.
Yes. The EOS system delivers about 90% less radiation than a standard X-ray, around ten times less. This makes it one of the lowest-dose options available for full-length weight-bearing imaging.
You stand still inside the EOS machine for a few seconds while it takes the images. There is no injection, no contrast dye and no enclosed tunnel. The whole imaging process is quick and simple.
Absolutely. Your body works as a connected chain from your feet to your head. A pelvic tilt or a knee alignment issue can change how force travels down to your ankle, overloading one side. This is exactly why whole-body standing imaging is so valuable.
If you have sudden severe pain, significant swelling after a new injury, numbness, weakness, loss of feeling in your foot, or you cannot bear any weight at all, please get urgent medical help. Contact your doctor, call your local emergency number, or go to the nearest emergency department.
Ready to find out why your ankle keeps giving way?
A free video consultation lets you talk through your history with our team from home. Together you can decide whether travelling to London for a standing alignment scan is the right next step.
Book a free video consultationWritten by Abbas Dhami (Specialist Diagnostic Radiographer)
Sources
- Hiller CE, Kilbreath SL, Refshauge KM. Chronic ankle instability: evolution of the model. Journal of Athletic Training. 2011;46(2):133-141.
- Gribble PA, Bleakley CM, Caulfield BM, et al. Evidence review for the 2016 International Ankle Consortium consensus statement on the prevalence, impact and long-term consequences of lateral ankle sprains. British Journal of Sports Medicine. 2016;50(24):1496-1505.
- NHS. Sprains and strains. nhs.uk. Available at: https://www.nhs.uk/conditions/sprains-and-strains/
This page is general information and not a diagnosis.
ScanAlign is the trading name of CoreMed Solutions Ltd and operates under The Harley Street Hospital's CQC licence.