Why Do I Keep Spraining the Same Ankle?
Repeated sprains in the same ankle usually point to chronic ankle instability. When the outer ligaments stretch or tear and never fully heal, the joint stays loose. Your balance reflexes weaken too, so the ankle gives way more easily. A standing alignment scan can reveal whether your foot shape or leg alignment is adding extra strain.
Key takeaways
- Chronic ankle instability means the ankle keeps giving way after a previous sprain.
- Loose ligaments and poor proprioception (your body's sense of joint position) are the main drivers.
- Your foot shape and overall leg alignment can make reinjury more likely.
- Standing, weight-bearing imaging shows alignment problems that lying-down scans can miss.
- A proper diagnosis guides the right rehabilitation or specialist referral.
What is chronic ankle instability?
Chronic ankle instability is a condition where the ankle repeatedly gives way, especially on uneven ground or during activity. It typically develops after one or more ankle sprains that did not fully recover.
When you roll your ankle, the outer (lateral) ligaments stretch or partially tear. The most commonly 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, which 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 beneath you. The result is a frustrating cycle: sprain, partial recovery, then another sprain.
How do you know if your ankle is unstable?
The hallmark sign is the ankle giving way, but there are several other clues to look for.
The ankle rolls inward unexpectedly, especially on uneven surfaces or when changing direction.
Puffiness around the outer ankle that comes and goes, often after walking or sport.
You feel the ankle is wobbly or that you cannot trust it, particularly on stairs or slopes.
A dull ache along the outer ankle that never quite settles, even months after the last sprain.
If you also notice difficulty balancing on the affected foot with your eyes closed, that is a strong signal that proprioception has been compromised.
What causes an ankle to keep spraining?
The original sprain is the trigger, but several factors explain why some ankles recover fully while others do not.
Returning to activity before the ligaments and balance reflexes have fully recovered is the most common reason.
A high-arched (cavus) foot naturally tilts the heel inward (hindfoot varus), placing 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 leg and act as dynamic stabilisers. Weakness here leaves the ankle exposed. This can also lead to peroneal tendonitis.
People with hypermobility syndrome are naturally more flexible in their joints. This extra range of motion can mean the lateral ligaments offer less passive support, making recurrent sprains more likely.
How does standing imaging help with ankle instability?
Standing, weight-bearing imaging captures your ankle, foot and entire leg under real loading conditions. This is the only way to see how your bones and joints line up when 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, arch height and how your ankle, knee and hip stack above each other. Subtle 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 conventional X-ray or CT 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 appear when you are upright and bearing weight can be completely hidden.
A gait analysis can add further detail about how you move, but ScanAlign standing EOS imaging gives the structural picture that underpins everything else. By showing the full chain from your foot through your knee to your hip, it helps your clinician understand whether an alignment issue higher up is contributing to your ankle problem.
When MRI is more useful: EOS excels at showing bones, joints and alignment. If your specialist needs to assess the ligaments, tendons, cartilage or other soft tissues around the ankle in detail, MRI is usually the better tool. The two scans complement each other well.
How do you strengthen a weak ankle after a sprain?
Rehabilitation is the cornerstone 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 tailor a programme to your findings.
Single-leg standing, wobble boards and eyes-closed balance drills retrain the nerve pathways that protect the joint.
Resistance-band exercises that work 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 provide external support during activity while strength and balance catch up.
If imaging shows a structural factor like hindfoot varus or a cavus foot, an orthotist may recommend a corrective insole.
Getting a clear picture of the underlying structure first helps ensure your rehabilitation targets the right problem, rather than just treating the symptoms.
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 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, leaving 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 prevent another roll.
They are closely related. Chronic ankle instability is the underlying condition. Recurrent ankle sprains are the events it causes. Not everyone with instability sprains frequently, some 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 reinjury.
An EOS scan captures your entire 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 reveals alignment details, such as hindfoot tilt and arch height under load, that a lying-down X-ray can miss.
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 discuss your situation before committing.
Pricing details are on our website. Please visit our FAQs page for up-to-date cost information.
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 captures the images. There is no injection, no contrast dye and no enclosed tunnel. The whole imaging process is quick and straightforward.
Absolutely. Your body works as a connected chain from your feet to your head. A pelvic tilt or 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 experience sudden severe pain, significant swelling after a new injury, numbness, weakness, loss of feeling in your foot, or you are unable to bear any weight at all, please seek urgent medical attention. Contact your GP, call 111, or go to A&E.
Ready to find out why your ankle keeps giving way?
A free video consultation lets you discuss your history with our team and decide whether 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.