Chronic ankle instability

What is chronic ankle instability?

Chronic ankle instability, commonly abbreviated as CAI, is a condition in which your ankle continues to feel unreliable after repeated sprains. Approximately 20% to 40% of people who suffer an ankle ligament injury eventually develop these symptoms, often because the initial injury was not fully rehabilitated.

Two underlying problems may occur at the same time. The lateral ankle ligaments, particularly the ATFL and CFL, may have become overstretched and no longer hold the joint together sufficiently. In addition, proprioception may be impaired. This is the ankle’s sense of movement, which normally allows it to react immediately to unexpected strain. As a result, your ankle may respond unpredictably on uneven ground or during sudden movements.

Common symptoms

The symptoms of chronic ankle instability are often subtle during everyday activities but become much more noticeable during sports or unexpected movements. Many people become accustomed to the symptoms and start compensating without realising it.

Common signs include:

• Repeated sprains of the same ankle, sometimes after only a minor misstep
• A feeling that the ankle gives way or rolls during walking, also known as a “giving way” sensation
• Persistent swelling or tenderness on the outside of the ankle
• Reduced confidence on uneven surfaces such as forest paths or paving stones
• Pain after prolonged standing or walking
• Avoiding certain movements or sports because of fear of another sprain
• Stiffness in the morning or after prolonged rest

Do you recognise these symptoms? Do not continue walking around with them. Chronic ankle instability rarely resolves on its own and increases the risk of premature ankle osteoarthritis.

Causes and risk factors

The most common cause of chronic ankle instability is a previous sprained ankle that was not fully rehabilitated. After a sprain, most people are pain-free again within a few weeks and return to normal activity, even though the ligaments and sense of movement have not yet regained their previous strength.

Factors that increase the risk include:

• Multiple previous ankle sprains without targeted rehabilitation
• Returning to sports too early after a previous sprain
• Weak peroneal muscles and tendons, which actively stabilise the ankle
• Reduced proprioception and balance on one leg
• Genetically determined ligament laxity
• Excess body weight, which increases the load on the joint
• Sports involving frequent changes of direction, such as football, basketball, and tennis

Previous ankle sprains are particularly important. Every time the same ankle gives way, the ligaments stretch further and the sense of movement becomes weaker. Without treatment, this creates a vicious cycle in which each new sprain occurs more easily than the previous one.

Mechanical versus functional ankle instability

Chronic ankle instability has two different causes that often occur together but require different approaches.

Mechanical instability means that the ankle ligaments have physically become overstretched or torn. This gives the joint too much movement in certain directions. A physiotherapist can assess this using specific tests that measure joint laxity, such as the anterior drawer test and the talar tilt test.

Functional instability means that your sense of movement and muscular reflexes are no longer working optimally. Your ligaments may still be sufficiently intact, but your brain and muscles do not react quickly enough when your ankle is about to roll. This can be measured using the Cumberland Ankle Instability Tool, a clinical questionnaire that evaluates the feeling of instability.

Treatment differs depending on the type of instability. Mechanical instability often responds to stabilisation training, although surgery such as the Broström procedure may sometimes be considered. Functional instability can almost always be treated conservatively with proprioception training and targeted strengthening exercises.

What you can do yourself

If you notice that your ankle is becoming increasingly unreliable, several adjustments may already help before you visit a physiotherapist.

You can start by doing the following:

• Wear an ankle brace or use tape during sports and high-risk activities to prevent new sprains
• Choose shoes with strong lateral support and a higher upper
• Temporarily avoid extremely uneven surfaces, such as forest trails, unless you are wearing a brace
• Practise balancing on one leg every day, for example while brushing your teeth
• Strengthen your calf and shin muscles by walking on your toes and heels
• Take enough time for a proper warm-up before exercising, especially in cold weather

These adjustments reduce the risk of another sprain, but they do not resolve the underlying instability. Targeted professional guidance is needed for lasting recovery.

Assessment and treatment plan at De Fysio Man

At De Fysio Man, we assess chronic ankle instability from several perspectives. We want to understand whether the problem is mainly mechanical, functional, or a combination of both, and which movement patterns contribute to your symptoms.

During the assessment, we evaluate:

• Your ankle’s range of motion in every direction
• Ligament laxity using specific clinical tests
• The strength of your calf muscles, shin muscles, and peroneal muscles and tendons
• Proprioception using single-leg balance tests with the eyes open and closed
• Your walking, running, and jumping technique
• Compensatory movements in the knee, hip, and trunk

Based on these findings, we create a personalised treatment plan for your chronic ankle instability.

Treatment may include:

• Proprioception training using a balance board, wobble cushion, and instability exercises
• Strength training for the calf, foot, and peroneal muscles and tendons
• Manual therapy for movement restrictions in the ankle joint
• Advice on using a brace during sports and daily activities
• Sport-specific exercises to support your return to sports
• Advice on footwear and, where necessary, orthotic insoles for abnormal foot posture

The goal is to restore an ankle that can immediately correct itself during unexpected movements without requiring conscious thought.

Rehabilitation phases

Phase 1 – Assessing symptoms and controlling pain

During the first phase, we assess your symptoms and reduce any acute pain or swelling caused by recent sprains. We also determine whether the instability is mainly mechanical, functional, or a combination of both.

Phase 2 – Strength and basic control

During this phase, we build the strength of all the muscles that actively stabilise your ankle. The peroneal muscles and tendons on the outside of the lower leg are especially important because they absorb lateral forces that previously caused your ankle to roll.

Phase 3 – Proprioception and rapid correction

This is the most important part of recovery. Using a balance board, wobble cushion, and exercises on unstable surfaces, your ankle and brain learn to react quickly to disturbances again. This phase often takes several weeks and requires repetition to produce lasting results.

Phase 4 – Returning to sports and daily activities

Once your basic stability has returned, we add jumping, changes of direction, and sport-specific movements. A footballer requires a different rehabilitation programme from a runner or hiker. This allows you to regain confidence in situations where your ankle previously gave way, supported by guided sports physiotherapy.

Prevention and reducing the risk of recurrence

Even after full rehabilitation, an ankle that was previously chronically unstable remains slightly more vulnerable than an ankle that has never been injured. Continuing the exercises you have built up is therefore especially important.

Important prevention tips include:

• Continue balance exercises at least twice a week, even when you have no symptoms
• Use a brace or tape during sports with a higher risk of ankle injuries
• Keep the peroneal muscles and tendons strong with targeted exercises
• Avoid returning to full sporting activity without gradually building up the load
• Pay attention to early warning signs such as minor giving way or uncertainty
• Always have a new ankle sprain assessed promptly to prevent recurrence

An ankle that was previously chronically unstable can fall back into the same pattern. By consistently working on strength and proprioception, you can keep the instability under control and reduce the risk of long-term damage such as ankle osteoarthritis.

Your next step

Do not continue walking around with an ankle you cannot rely on. Every new sprain worsens the underlying problem and increases the risk of permanent damage. With a clear diagnosis and targeted rehabilitation, stability can usually be restored successfully, even if the symptoms have been present for years.