Chronic Ankle Instability (CAI)

Chronic ankle instability (CAI) can have a massive impact on a person’s quality of life and overall function, often arising from a simple ankle sprain. In this blog, we discuss the in’s and out’s of CAI and how physiotherapy can help diagnose, treat and prevent this condition.

CAI: What is it? Who gets it and how?

Ankle sprains are one of the most common sporting injuries, accounting for 15-20% of sports-related injuries.

The most common type of ankle sprain is known as the classic rolled ankle where the outside or lateral part of the ankle is affected. This type of injury generally occurs during a combined movement where the foot is pointed down and then twisted inwards – this is called an inversion ankle sprain.

While most people are able to recover well from an ankle sprain, 10-30% of patients can have recurrent ankle sprains which can lead to the development of CAI. CAI, in essence, is the aftermath of an ankle sprain where residual symptoms persist, causing ongoing pain, weakness and feelings of instability in the ankle 6-12 months after the initial injury.

Anatomy of the Ankle

As mentioned previously, most ankle sprains affect the lateral aspect of the ankle. There are many structures that provide stability to the lateral ankle, with ligaments playing a key role.

The three main ligaments of the lateral ankle are the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and the posterior talofibular ligament (PTFL). The ATFL is the weakest of the 3 ligaments and is pulled tight in the position of injury, making it the most common ligament to be injured. In more severe ankle sprains, it is common for the ATFL and the CFL to be injured concurrently.

Risk Factors

There are several factors that contribute to the development of CAI. These include:

• History of previous ankle sprains
• Younger age
• Higher BMI
• Underlying foot deformity
• Poor muscle strength around the ankle
• Altered landing mechanics
• Impaired balance

It’s also more common for female athletes to develop CAI compared to male athletes.

Signs and Symptoms of CAI

Patients with CAI often complain of recurrent ankle sprains or episodes of their ankle giving way. Additionally, patients with CAI may have ongoing symptoms such as pain, reduced ankle movements, ankle weakness, and reduced balance. They may also report reduced functional capacity which affects their ability to perform sport or even everyday tasks.

Diagnosing CAI

The diagnosis of CAI requires an in depth physical examination from a physiotherapist or other healthcare professional. As part of the physical examination, your physiotherapist may look at:

• Lower limb alignment, including foot posture
• Ankle movements
• Ligament laxity
• Muscle strength
• Balance

Additionally, your physiotherapist may ask you to complete a questionnaire, such as The Cumberland Ankle Instability Tool, to get an understanding of subjective feelings of ankle instability.

While imaging can be helpful in understanding what’s happening in the ankle, it shouldn’t be used in isolation to diagnose CAI.

Treatment Options

Treatment of CAI typically begins conservatively, with a personalised rehabilitation program provided by an experienced physiotherapist. Rehabilitation for CAI is focused on improving patients’ impairments and functional limitations. This may include:

• Movement retraining
• Strengthening exercises
• Balance and proprioception exercises
• Sport-specific training

Conservative management for CAI can take up to 12 weeks to see significant improvements. However, if a patient doesn’t respond well to rehabilitation during this time, they may be eligible for surgical management. If a patient chooses surgical management, post-op rehabilitation can take up to 6 months for the athlete to return to full sports participation.

Prevention Strategies

Prevention strategies play a crucial role in reducing the risk of CAI and other complications following an ankle sprain. 

The use of ankle braces or ankle taping is very common in sports and can be effective in preventing recurrent injuries. Additionally, a preventative rehabilitation program, also known as prehab, can be an effective way to prevent injury by targeting key risk factors specific to each patient.

Conclusion

In conclusion, CAI is a complex condition that can have significant implications for individuals, particularly athletes. Understanding the condition’s causes, symptoms, and treatment options is essential for effective management. With guidance from our experienced physiotherapists, individuals with CAI can regain stability and confidence in their ankles, empowering them to confidently return to everyday tasks and sporting activities.