Peroneal Tendinopathy (Peroneal Tendonitis)

Peroneal tendonitis is a common overuse injury causing pain on the outside of the ankle. It usually develops gradually, particularly in runners and athletes, when the tendons become irritated from repeated friction around the ankle bone.

Peroneal Tendonitis Symptoms

Do I have Peroneal tendonitis/tendinopathy? The most common symptoms include:

• Pain and swelling on the outside of the ankle
• Pain is often worse during activity, but improves with rest
• Tenderness when pressing in on the outside of the ankle
• Increased pain when stretching the peroneal muscles
• Morning stiffness around the tendon
• Pain when walking on uneven ground
• Weakness when pushing off or changing direction
• Clicking or snapping sensation if the tendon is unstable

Diagnosis & assessment

A simple way to assess is by stressing the tendon slightly.

Resisted eversion test

The peroneal muscles work to turn the foot outwards (eversion).

• Sit with your leg extended.
• Attempt to turn your foot outwards against resistance.
• Pain along the tendon may indicate peroneal tendinopathy.

Passive inversion stretch

Stretch the peroneal muscle with the foot turned inwards.

• Gently move the foot inwards (inversion).
• Pain or discomfort along the tendon may indicate injury.

Palpation test

Carefully press along the tendon behind the outer ankle bone.

• Local tenderness is common in peroneal tendinopathy.
• Compare with the uninjured side.

A healthcare professional may confirm the diagnosis using an ultrasound or MRI scan if required.

Conditions with similar symptoms

The following injuries often have similar symptoms, therefore important to rule out or be aware of:

• Peroneal tendon tear
• Peroneal tendon dislocation
• Sinus tarsi syndrome
• Lateral ankle ligament sprain
• Cuboid syndrome
• Stress fracture of the fibula
• Stress fracture of the talus

What is Peroneal Tendonitis?

Peroneal tendonitis is inflammation or degeneration of the peroneal tendons on the outside of the ankle.

Anatomy

The Peroneal muscles consist of the Peroneus longus and Peroneus brevis. They are located at the back & outside of the lower leg.

The peroneal tendons pass down the back and underneath the lateral malleolus (bony bit on the outside of the ankle). Overuse causes the peroneal tendons to rub on the bone and as a result, become inflamed.

The peroneus longus tendon runs around the back of the lateral malleolus and under the foot. It attaches to the outside of the first metatarsal and cuneiform bones.

The peroneus brevis also passes around the back of the lateral malleolus. It attaches to the outside of the foot at the base of the 5th metatarsal. The muscles plantarflex (point downwards) and evert (turn outwards) the foot.

Tendonitis or tendinopathy?

The term Peroneal tendinopathy rather than Peroneal tendonitis may be more appropriate, especially in chronic cases³. This is because tendinopathy describes degeneration of the tendon as opposed to just acute inflammation. If your injury is quite recent, for example, a few days old, then you may have acute inflammation (tendonitis).

However, in chronic cases, acute inflammatory cells are unlikely to be present. Therefore, degeneration (tendinopathy) of the tendon is a more accurate description.

What causes Peroneal tendinopathy?

Overuse is the primary cause, however, there are a number of factors that can increase your risk of injury.

• Sudden increase in running mileage
• Running on cambered roads¹
• Excessive ankle instability following ankle sprains
• High foot arches (pes cavus)
• Inappropriate footwear
• Sports involving repeated cutting and turning movements
• Peroneal tendon subluxation or dislocation
• Poor calf muscle flexibility

Peroneal Tendonitis Treatment

The aim of treatment is to reduce the load on the tendon, reducing pain and inflamation. Then gradually restore strength.

Rest

Rest is important when treating peroneal tendonitis. As it is an overuse injury, continuing to train prevents healing. However, it may be possible to do other activities such as swimming or cycling to maintain fitness. The rule is if it hurts during, immediately after, or the following day, then don’t do it!

Cold therapy

Apply the PRICE principles (protection, rest, ice, compression, and elevation). This helps reduce swelling, pain, and inflammation. Apply for 10 minutes every hour, to begin with, reducing frequency as your symptoms improve.

Supports & braces

Wear an ankle support or brace which has a high level of lateral support, particularly over the outside of the ankle. This protects and supports the injured tendon, therefore, allowing it to heal. If your injury has passed the acute stage then a simple neoprene ankle wrap is ideal as it also acts as a heat retainer.

Ankle taping for Peroneal tendonitis

Tape your ankle. This provides a great deal of support and protection to the ankle. It can be done in the same way as an ankle sprain taping technique.

Medication

A doctor may prescribe NSAIDs (non-steroidal anti-inflammatory drugs) to reduce pain and inflammation. Do not take Ibuprofen if you have Asthma.

Sports massage for Peroneal tendonitis

Sports massage to the peroneal muscles may help reduce muscle tightness, which in turn reduces the strain on the tendon. However, strengthening exercises and gradual load progression remain the most important components of rehabilitation. Massage techniques are similar to those for a calf strain.

Peroneal Tendonitis exercises

Stretching your calf muscles and peroneal muscles is important. Tight peroneal muscles increase the friction between the peroneal tendon and the bone. Gently stretching the muscles over time will reduce the tension in your muscle.

Peroneal muscle stretch

A specific stretch to target the Peroneal muscles is done by stretching your foot into an ‘inverted position’. This is more easily done in a sitting position.

Calf muscle stretches

If you simply rest without stretching or addressing the initial causes, the pain will go. However, it is likely to return once you resume normal training.

Rehabilitation exercise progression

In addition to stretching, strengthening exercises begin with static or isometric holds and progress:

1. Isometric eversion exercises
2. Resistance band eversion
3. Single-leg balance exercises
4. Calf raises
5. Hopping and sport-specific drills

Recovery time

Recovery depends on the severity and duration of symptoms.

• Mild cases may improve within 2 to 6 weeks.
• More persistent cases often require 6 to 12 weeks of rehabilitation.
• Long-standing tendinopathy may take several months to resolve fully.

Returning to sport too early often leads to recurrence.

Prevention

You can reduce your risk of recurrence by:

• Increasing training gradually.
• Maintaining good ankle strength and balance.
• Completing rehabilitation after ankle sprains.
• Wearing appropriate footwear.
• Addressing any underlying biomechanical problems.

References & further reading

1. Clarke HD, Kitaoka HB, Ehman RL. Peroneal tendon injuries. Foot Ankle Int 1998;19(5):280–8.
2. Tjin ATER, Schweitzer ME, Karasick D. MR imaging of peroneal tendon disorders. AJR Am J Roentgenol 1997;168(1):135–40
3. van Dijk CN, Karlsson J, Calder J, et al. The ESSKA-AFAS international consensus statement on peroneal tendon pathologies. Knee Surg Sports Traumatol Arthrosc. 2018;26(10):3096-3107.