Peroneal tendonitis is a condition characterized by irritation or inflammation of the two peroneal tendons, the peroneus longus and peroneus brevis, which course along the outside of the ankle and foot. These cord-like structures are responsible for stabilizing the foot and ankle, particularly during activities that involve pushing off or rolling the foot outward. When these tendons become repetitively overloaded or strained, the resulting inflammation can lead to a distinct set of physical sensations.
Where the Pain is Located
The discomfort from peroneal tendonitis is highly localized and follows the anatomical path of the affected tendons. The two peroneal tendons descend the lower leg and run together, passing through a groove directly behind the prominent bony bump on the outside of the ankle, known as the lateral malleolus. This specific path is often the primary site of tenderness and pain.
The peroneus brevis tendon inserts onto the base of the fifth metatarsal, the long bone that runs along the outside edge of the foot. Consequently, the pain often tracks from behind the outer ankle bone and can extend forward along the side of the foot to this attachment point. Pressing directly on the area immediately behind and below the lateral malleolus will typically elicit a sharp increase in discomfort.
The peroneus longus tendon, which travels under the arch of the foot, can occasionally refer pain to the lateral arch, giving a bruise-like ache along the outer edge. The pain is usually superficial and easily pinpointed, distinguishing it from deeper joint or bone pain. This focused, palpable tenderness makes the location a defining feature of the condition.
The Quality and Intensity of the Discomfort
The subjective experience of peroneal pain can vary dramatically, often depending on the chronicity and severity of the irritation. For many, the baseline feeling is a deep, persistent ache or throb that settles into the outer ankle region, particularly after periods of weight-bearing activity. This dull discomfort is a classic sign of generalized tendon irritation.
This background ache can be punctuated by moments of sharp, sudden pain, especially during specific movements like rolling the foot outward or pushing off forcefully. When the condition is more acute, or the protective sheath around the tendon (tenosynovitis) is inflamed, the pain can manifest as a burning sensation. The intensity generally follows a predictable pattern related to activity levels, often escalating from mild annoyance to a significant hindrance during prolonged walking or running.
A notable characteristic of the pain is its fluctuation throughout the day, often referred to as “startup pain.” Patients frequently report significant discomfort and stiffness with their first steps in the morning or after sitting for a long time. This initial pain tends to ease slightly after a few minutes of gentle movement, but then worsens considerably following extended periods of being on the feet.
Related Sensations and Stiffness
Peroneal tendonitis is accompanied by several distinct physical sensations that signal underlying inflammation. One common manifestation is localized swelling or puffiness, which can be observed just behind and below the outer ankle bone. This visible enlargement results from inflammatory fluids accumulating in the irritated tendon sheath.
The affected area may also feel noticeably warm to the touch compared to the surrounding skin, which is another physical sign of an active inflammatory process. This warmth and swelling contribute to a feeling of tightness or stiffness, especially following periods of immobility. This stiffness makes the ankle feel restricted, and the range of motion may seem limited until the tissue is gently moved.
Mechanical sensations are also frequently reported, separate from the pain and stiffness. Individuals may experience a distinct clicking, popping, or snapping feeling or sound around the outer ankle with certain movements. This sensation occurs if the inflamed tendons are catching or subluxing—slipping out of the shallow groove behind the lateral malleolus—or if the damaged tendon sheath causes friction. In some cases, the inflammation can irritate the nearby sural nerve, leading to tingling or numbness along the outer edge of the foot.