Introduction 

What is peroneal tendonitis?

Peroneal tendonitis is a condition characterised by inflammation of the peroneal tendons, which are located along the outer edge of the foot and play an important role in ankle movement.¹ This inflammation is often caused by overuse or repetitive stress on the tendons.¹ Individuals with peroneal tendonitis may experience pain along the outer edge of the foot, swelling, tenderness, and weakness or instability in the ankle.¹ 

The diagnosis of peroneal tendonitis involves a physical examination by a healthcare professional, as well as imaging studies such as X-rays or MRIs. Treatment usually focuses on rest, modifying your physical activity, ice, elevation, and the use of non-steroidal anti-inflammatory drugs (NSAIDs).² Physical therapy and rehabilitation exercises are also commonly recommended.²

Read on to learn more about peroneal tendonitis.

Anatomy of the peroneal tendons

The peroneal tendons are located along the outer edge of the foot, running parallel to the ankle.¹ There are two peroneal tendons, which are called the peroneus longus and peroneus brevis tendons.² They play a crucial role in supporting and stabilising the foot and ankle.²

The peroneus longus tendon extends from the calf muscles to the bottom of the foot. The peroneus brevis tendon is located above the peroneus longus.¹ Together, these tendons contribute to the stability and balance of the ankle joint and help maintain proper foot alignment when the foot is extended outwards.¹ The peroneal tendons are also actively involved in foot and ankle movement, enabling actions such as pointing the toes, turning the ankle outward, and providing stability during weight-bearing exercises.³ 

These tendons must function in a coordinated way to help you maintain your balance and prevent excessive inward rolling of the foot, a condition which is known as overpronation.³ Understanding the location and function of these tendons is important to grasp the impact of peroneal tendonitis on foot mechanics and mobility.

Source: NHS Lanakshire https://www.nhslanarkshire.scot.nhs.uk/services/physiotherapy-msk/peroneal-tendinopathy/ 

Causes of peroneal tendonitis

There are several different causes of peroneal tendonitis, which are outlined below.^3,4

Overuse and repetitive stress 

Peroneal tendonitis often occurs from overuse and repetitive stress on the foot and ankle. This is commonly seen in activities that involve frequent, intense movements such as running, jumping, and walking on uneven surfaces, such as hiking. The strain placed on the peroneal tendons during these activities can lead to inflammation and irritation, contributing to the development of tendonitis.

Trauma or injury

Trauma or acute injury to the foot or ankle can also be a causing factor for peroneal tendonitis. Sudden twists, sprains, or impacts may cause damage to the peroneal tendons, resulting in inflammation and pain. Sports-related injuries or accidents that affect the ankle can significantly increase the risk of developing peroneal tendonitis.

Anatomical factors 

There are certain anatomical factors which can predispose individuals to peroneal tendonitis. Variations in foot structure, such as high arches or flat feet, can alter the mechanics of the foot and ankle, leading to increased stress on the peroneal tendons which can be exacerbated by high frequency/intensity activities. Understanding these anatomical factors is important in assessing the underlying causes of peroneal tendonitis and implementing preventive measures.

Signs and symptoms

Pain along the outer edge of the foot

One of the primary indicators of peroneal tendonitis is pain located along the outer edge of the foot. This discomfort is often worsened during weighted activities or movements that involve ankle flexion and extension. The intensity of the pain may vary between individuals, ranging from a dull ache to sharp, stabbing sensations.^3,4

Swelling and tenderness

Swelling and tenderness around the affected tendons are common symptoms of peroneal tendonitis. Inflammation can lead to visible swelling on the foot, and the affected area may feel tender to the touch. Swelling may contribute to a feeling of tightness in the ankle region, further increasing the discomfort associated with peroneal tendonitis.^3,4

Instability or weakness in the ankle

Individuals with peroneal tendonitis may experience a sense of instability or weakness in the ankle. The affected tendons play a crucial role in stabilising the ankle joint; when inflamed, they may compromise this stability. This can result in feelings of unsteadiness, especially during weighted activities or when changing direction during walking or running.^3,4

Recognising and addressing these signs and symptoms is essential for the accurate diagnosis and timely intervention of peroneal tendonitis.

Diagnosis

Diagnosis of peroneal tendonitis often involves a physical examination by a healthcare professional as well as imaging studies:

Physical examination 

Diagnosing peroneal tendonitis begins with a thorough physical examination conducted by a healthcare professional. The examination may involve assessing the affected foot and ankle for signs of tenderness, swelling, and range of motion. The healthcare provider may ask about the individual's medical history, including recent activities or injuries, to gather relevant information for an overall assessment.⁵

Imaging studies (X-rays, MRI)

To further investigate the extent of peroneal tendonitis and rule out other potential causes of symptoms, imaging studies such as X-rays or magnetic resonance imaging (MRI) may be recommended. X-rays help identify any unknown bone abnormalities, fractures, or joint issues, while an MRI provides detailed images of soft tissues, including the peroneal tendons.⁵

These diagnostic tools aid healthcare professionals in confirming the diagnosis, assessing the severity of the condition, and forming an appropriate treatment plan tailored to the individual's specific needs.

Treatment options

Rest and activity modification 

The best treatment for peroneal tendonitis involves allowing the affected tendons to heal through rest and activity modification. This may involve reducing or avoiding activities that worsen symptoms, providing the tendons with the necessary time to recover and minimise further irritation.^6,7

Ice and elevation

To alleviate pain and reduce inflammation associated with peroneal tendonitis, the application of ice and elevation is commonly recommended. Ice packs can be applied to the affected area to constrict blood vessels and decrease swelling, while elevation helps promote drainage of excess fluids, contributing to the overall reduction of inflammation.^6,7

Non-steroidal anti-inflammatory drugs (NSAIDs)

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), such as ibuprofen or naproxen, may be prescribed or recommended to manage pain and inflammation. These medications work by inhibiting the production of certain chemicals in the body that contribute to the inflammatory response.^6,7

Physical therapy and rehabilitation exercises

Physical therapy is a key component of peroneal tendonitis treatment, aiming to strengthen the muscles around the ankle and improve flexibility. A physical therapist may advise specific exercises to improve the stability and function of the peroneal tendons. Rehabilitation exercises are tailored to the extent of the individual's condition and progress, promoting a controlled return to normal activities while decreasing the chances of re-injury.^6,7

When to seek medical attention

Knowing when to seek medical attention for peroneal tendonitis is crucial for timely intervention. The following signs highlight instances where professional evaluation becomes necessary.

Persistent or severe pain

Individuals experiencing persistent or severe pain associated with peroneal tendonitis should seek medical attention. Persistent discomfort that does not improve with rest or over-the-counter pain medications may indicate an underlying issue that needs professional attention. Severe pain can be indicative of significant inflammation or potential complications.⁸

Difficulty walking or carrying weights 

Difficulty walking or bearing weight on the affected foot is a clear sign that peroneal tendonitis may significantly be impacting mobility. If the condition interferes with the ability to do normal activities or bear weight without excessive discomfort, seeking medical attention is crucial.⁸

Signs of infection of worsening symptoms

Any signs of infection, such as increased redness, warmth, or the presence of discharge around the affected area, fever, and sweating warrant immediate medical attention. Additionally, if symptoms worsen despite treatment or preventative measures, it is essential to consult a healthcare professional promptly to manage peroneal tendonitis effectively.⁸

Summary

Peroneal tendonitis is a condition marked by inflammation along the outer edge of the foot. The peroneal tendons, positioned along the outer side of the foot, play a vital role in stabilising the ankle and facilitating foot movement. Overuse, trauma, and anatomical factors are common contributors to the development of peroneal tendonitis, leading to symptoms such as pain, swelling, and ankle instability. 

Peroneal tendonitis is diagnosed via a thorough physical examination and, if necessary, imaging studies like X-rays or MRI scans. Treatment strategies for peroneal tendonitis vary between individuals. Rest and activity modification provide the tendons with the necessary time to heal, while the application of ice and elevation helps alleviate pain and reduce inflammation. NSAIDs may be recommended to manage pain and swelling. 

Physical therapy, including targeted rehabilitation exercises, plays a key role in strengthening the surrounding muscles and restoring optimal function. Recognising when to seek medical attention is pivotal. 

Persistent or severe pain, difficulty walking, or signs of infection warrant consultation with a healthcare professional. By proactively managing peroneal tendonitis and following recommended treatments, individuals can improve the prospects of a successful recovery and long-term foot health.