Peroneus saltans - the jumping tendon on the outside of your ankle

Running along the outer side of the lower leg are the peroneus longus and peroneus brevis muscles. These tendons run behind the lateral malleolus. This is the outer ankle tubercle. The peroneal tendons run in a narrow groove of the fibula. There, they are held in place by a firm connective tissue band, which we also call a retinaculum.

In peroneus saltans, this retinaculum loses its firmness, causing the tendons to lose their proper anatomical location. During movement, they can then shift forward, over the malleolus. This causes the typical snapping or clicking sensation that people may recognise.

In most cases, this injury is caused by a combination of dorsiflexion (foot upward) and eversion (foot outward) under vigorous tightening of the peroneal muscles, for example during a sudden landing or turning movement. This mechanism is common in sports such as football, basketball, skiing, gymnastics and field sports.

Of course, not everyone who sprains their ankle develops peroneal saltans. Congenital predisposition plays a role. Some people have a relatively flat or even convex groove behind the ankle knob, which means the tendons have less support. A low-through muscle belly of the peroneus brevis, extra tendon muscles present such as the peroneus quartus, or a cavovarus foot position with a high instep and inward-tilted heel can also increase the risk.

In a recent study, Nishimura et al (2023) showed that people with relatively abundant tissues may develop peroneal saltans faster. By this we mean that relatively too much is present in the narrow tendon canal behind the outer ankle, literally giving the peroneal tendons too little space. As a result, they are more easily pushed out of their normal position when moving, leading to the characteristic snapping or springing. This occurs partly due to a low-thickness muscle belly of the peroneus brevis, presence of additional muscle such as the peroneus quartus. And/or by thickening of the tendon sheath or tendons after repeated injuries or irritation.

Almost always, the characteristic snapping or shooting sensation on the outside of the ankle is described often together with pain behind the malleolus. There may be a feeling of instability as if you are sinking through the ankle. Sometimes the shifting tendon is even visible or palpable under the skin. Swelling around the tendon is also common.

With acute symptoms, there has always been a clear moment of origin. So a sprain or twist with a sudden loud “plop”. With a more long-term course, the symptoms develop gradually. People notice that the ankle keeps clicking during specific movements. The frequent subluxation irritates the tendons and may even cause damage, especially in the peroneus brevis.

Scientific studies show that dynamic ultrasound is the most reliable method to diagnose peroneal tendon instability. The major advantage is that we can assess the tendons in motion, precisely during the movement where they shoot forward. A recent study by Melville et al (2024) showed that dynamic ultrasound has a sensitivity of 100% for detecting peroneal tendon subluxations, while an MRI - which takes only static images - recognises only 66% of these instabilities. This means that MRI misses a significant proportion of true luxations, while ultrasound does capture this well. At Fysio Fitaal, dynamic ultrasound is available to diagnose peroneus saltans.

During the examination, we image the area behind the lateral malleolus and ask for active dorsal flexion and eversion, possibly also against resistance. This allows us to see immediately whether the tendons jump forward, whether the retinaculum can still provide stability, or whether there is thickening, tearing or a large displacement of the tendons relative to each other. It is important to compare the other side to rule out normal anatomical variation.

In non-athletes with peroneal tendon luxation, treatment without surgery may be considered. Here, the ankle is usually immobilised for about six weeks in plaster or a walking boot, often in slight plantar flexion, with success rates of 60-80% being described. During this phase, we at Physio Fitaal guide the maintenance of strength in hip, knee and trunk, followed by gradual mobilisation. From about six weeks, targeted build-up with strength training of the peroneal muscles in strength and functional load starts. With this approach, total rehabilitation takes an average of three to six months before full sports or work load is safely possible.

In (elite) athletes with chronic instability or when conservative therapy does not yield sufficient results, surgical intervention is advised. The most commonly used technique is repair of the superior peroneal retinaculum (SPR repair). This is often combined with deepening the tendon groove of the fibula to structurally improve its position. This surgery shows good results: more than 94% of patients return to sport, with a very low risk of a new injury in this region, this is even below 1%. After surgery, a carefully constructed programme follows in which the ankle has limited load capacity in the first weeks, after which strength, motion control and sport-specific load are gradually restored. Most athletes can safely return to competitions between four and six months after surgery.

At Physio Vital we combine ultrasound diagnostics with a clear rehabilitation programme for both peroneal nerve complaints with or without surgery. We monitor recovery objectively with tests and measurements, match the treatment plan to your sports and work goals and guide you step by step towards safe full load.

Peroneus saltans is an often missed cause of persistent ankle pain after a sprain, wrongly attributed to ankle ligament injury. With early recognition and proper management, the prognosis is favourable. Are you experiencing a snapping tendon, instability or persistent pain on the outside of your ankle? Then make an appointment at Fysio Fitaal. We will clarify your symptoms and work together towards a full recovery.

Nishimura A. et al, Risk factors for recurrent peroneal tendon dislocation, Journal of Foot and Ankle Surgery (Asia-Pacific), 2023.

Melville DM et al, Dynamic Ultrasound Outperforms MRI for Detecting Peroneal Tendon Subluxation, Journal of Clinical Medicine, 2024.

Bakker et al (2020). Management of peroneal tendon instability: a systematic review. Foot & Ankle International.

Roster T. et al. (2019). Surgical treatment of peroneal tendon dislocation: outcomes and return to sport. Journal of Foot & Ankle Surgery.

ESSKA-AFAS Consensus Statement (2018).
Diagnosis and treatment of peroneal tendon pathology.