Your ankles are the unsung heroes of every step you take. They power your dash to the front door, support you as you squeeze into your jeans, and absorb the impact of every single stride on your morning jog. We take these tireless joints for granted—until a sharp, debilitating pain on your outer ankle stops you in our tracks. This is often the calling card of peroneal tendonitis, nowadays more commonly known as peroneal tendinopathy. Now the inflammation and dysfunction of the tendons on the outside of your ankle turn the simplest movements into a painful chore.

If a sharp pain and instability on the outside of your ankle are making every step a challenge, you might have Peroneal Tendonitis.

A tendon attaches muscle to bone, so you will usually find these structures close to a joint. The peroneal muscles attach to your fibula, forming the outside, or lateral compartment, of your lower leg. As the name suggests, the peroneus longus muscle (including the tendon) is longer than peroneus brevis. These muscles run down in the direction of your ankle, where both peroneal tendons run in a groove behind your outer ankle bone, of malleolus. From there, the peroneus brevis tendon inserts on the outside of your foot, whereas the peroneus longus tendon passes underneath your foot to insert at the base of your big toe. The peroneal muscles are primarily responsible for moving the sole of your foot outwards, in other words away from the other foot.

Your peroneal tendons cross the outside of your ankle joint to anchor the peroneal muscles to the bones of your foot. This anchor creates a leverage system that allows movement when the muscle contracts. When your foot is not bearing weight, the peroneal muscles work together to plantarflex your ankle, like a ballerina. These muscles also evert your ankle, in other words turn the foot outwards. When your foot is weight bearing, like when you’re standing or walking, the peroneus longus tendon also supports the transverse arch of your foot and provides stability. This means that the peroneal muscles and tendons are important for dynamic ankle stability, i.e. stability with movement.

Tendons are infamous for their poor blood supply. This means that tendons take longer to heal than a muscles. If there is excessive load at this muscle anchor site, some of the tendon fibers may fray and cause inflammation. Some causes of excessive load may be starting a new activity, like boot camp, or increasing your exercise intensity, like running faster or more often. Runners are especially susceptible to peroneal tendon pain, especially if they have muscle imbalances.

Most of us have “muscle imbalances” because none of us move 100% symmetrically. If you favor one side to carry your laptop bag, it may cause imbalance from left to right. If you always run on the same side of the road the camber may cause muscle imbalance too. As the peroneal tendons become painful and weak from overuse, their ability to stabilize your ankle is compromised. This weakness contributes to the functional instability of your ankle, increasing the likelihood of sprains and placing even more stress on the already damaged tendons.

While often a chronic, overuse condition, the onset of peroneal tendinopathy can also be traced back to an acute injury. The most common cause is an inversion ankle sprain, where you roll you ankle inwards, damaging your peroneal tendons as they are stretched or compressed. Another acute injury could be a sudden, powerful contraction of the peroneal muscles, for instance, while trying to prevent a fall or during a rapid cutting maneuver in sports.

• Previous ankle injuries
• Training errors
• Improper techniques
• Barefoot walking
• Change in running style
• New or unaccustomed exercise
• Increase distance or speed of runs
• Running on the same side of the road or track every time
• New routine (exercise or dance)
• Sustained positions, like sitting with your foot at an awkward angle
• High foot arches
• Flat feet
• Muscle imbalances

At first you will feel sharp, acute pain when your tendon is pressurized by movement, like climbing stairs or changing direction. You will have pain and stiffness when you start to move, especially first thing in the morning, but the pain settles as your warm up. The pain also goes away completely with rest. Standing on one leg might be challenging, almost as if your balance isn’t what it should be. This phase is of short duration and your tendon still has potential to heal completely.

If you don’t take note of your stiff, painful ankle tendons, the tendon tissue begins to change to adapt to the overload. Unfortunately, it doesn’t adapt in a good way. New blood vessels and nerve endings form in the tendon. Your pain will be a constant, nagging discomfort and stiffness. It might settle a bit after your warmup, but activity usually makes it worse until the pain forces you to stop moving. Your ankle will feel less flexible now and you will be more susceptible to injury, like rolling your ankle.

In the late stage of peroneal tendinopathy, the tendons become thickened and these changes have become irreversible. You’ll have pain with your normal, everyday activities, like shopping, and constant stiffness around your ankle. Any extra activity like walking uphill of climbing stairs will be excruciating, with the pain taking a couple of days to settle.

Physiotherapists are experts in diagnosing musculoskeletal conditions, like peroneal tendinopathy. We perform a thorough physical assessment, using skilled hands-on techniques to pinpoint the exact source of your problem. Through specific strength and movement tests, we determine the health of your peroneal tendons and rule out other potential causes of your ankle pain, such as ligament sprains or joint issues. This comprehensive, hands-on approach allows us to make an accurate diagnosis and create a personalized recovery plan tailored specifically to you.

The bones of your lower leg and ankle will be visible with X-ray imaging, but not the muscles and tendons. Therefore, this is not a useful test to diagnose peroneal tendinitis or tendinopathy.

Diagnostic ultrasound is the image of choice for peroneal tendonitis. A sonar will show the soft tissue structures around the outside of your ankle, the integrity of the peroneus longus and brevis tendons. Inflammation or tears of the peroneal tendons will also be visible on sonar.

Magnetic resonance imaging is costly and unnecessary to confirm peroneal tendonitis. It can only be ordered by a specialist and enables a view of all the structures surrounding the ankle joint.

• Chronic Ankle Instability

This is the most common complication of untreated peroneal tendinopathy in a self-perpetuating cycle. As the tendons become weak and painful, their lose their ability to provide dynamic support to your ankle. This results in a functionally unstable ankle, characterized by repeated sprains and a persistent sensation of your ankle “giving way” during activity. Chronic ankle instability is both a cause and a consequence of peroneal tendon injuries.

• Peroneal Tendon Tears (Partial/Longitudinal)

If left untreated, the degenerative process of tendinopathy, until the weakened and disorganized collagen fibers of the tendon begin to fail. This is usually seen as longitudinal, or “split” tears, where the tendon frays and separates along its length, almost like a string unraveling.

• Peroneal Tendon Subluxation or Dislocation

This happens when one or both peroneal tendons slip out of their normal position. This is often caused by an acute injury, like an ankle sprain. You will experience a painful popping or snapping sensation on the outside of their ankle during certain movements. Chronic, repeated subluxation means ongoing friction and mechanical irritation, which can lead to further tearing.

• Complete Tendon Rupture

Although less common than partial, longitudinal tears, a severely damaged and neglected tendon can eventually rupture completely. This is a traumatic event that results in acute pain, swelling, and weakness in the ability to turn your foot outwards.

• Sural Nerve Irritation or Neuroma

The sural nerve runs in close proximity to the peroneal tendons and which provides sensation to the outer border of your foot, Chronic inflammation, swelling, and scar tissue associated with peroneal tendinopathy can compress or irritate the nerve. This can lead to a burning pain, numbness, or tingling (paresthesia) over the outside of your foot.

If peroneal tendinopathy is ignored and left untreated, it rarely resolves on its own. Initially, the pain comes and goes, depending on your activity. Over time, the pain is there more often than not and it starts to limit what you can do. The injured tendon becomes rigid and stiff, until you eventually notice that you have trouble climbing down steps or walking uphill. This tendon stiffness makes it vulnerable to partial tearing, or even a complete rupture. As the structure of the tendon changes, trying to compensate for the injury and damage, a functional ankle instability develops. The muscles around your ankle become progressively weaker due to pain and disuse. Stiffness, muscle weakness and instability combined will start to change the way you walk, leading to an increased risk of recurrent ankle sprains. Every time you roll your ankle, there’s a little bit of extra strain and damage to the already struggling structures around your ankle. This whole sequence of events adds up to a chronic ankle instability, with abnormal loading on your ankle joint.

Physiotherapists are skilled to determine the severity of the injury of your peroneal tendon and any contributing factors. Addressing the root cause of your symptoms is crucial to prevent recurrence of your injury. We use techniques like myofascial release, joint mobilization and nerve mobilization to treat pain, restore mobility and decrease the risk of long-term complications. Modalities like laser, ultrasound and dry needling also help to speed up healing and recovery, while an individualized rehabilitation program addresses muscle weakness, imbalances and motor control.

Tendons are infamous for the long time it takes to heal, compared to other injuries like muscle tears. Full recovery and return to sport will take longer and should not be confused with the healing period. Each case is unique, so be patient and stick to the program. Peroneal tendonitis can take anything from 6 weeks to 6 months to heal completely.

In the first stage, we will need to see you twice a week for treatment. Once pain starts to improve and we can start adding loading to your rehabilitation program, we will see your for treatment once a week for the next 2-3 sessions. Thereafter, you will start to return to light activities, while continuing your home specific loading program. We will still see you once in two to three weeks to monitor progress and adapt your loading accordingly. Once you’ve returned to training or normal activities, we will see you once a month or every 6 weeks to monitor tissue adaptation and response to the increase in loading. The last thing you want is to go through the hard work of treatment, only to quit too soon and start all over again in a year or two.

• General practitioner: Your GP may prescribe anti-inflammatories or pain medication, if necessary.
• Braces: Long term use of a brace will lead to muscle weakness and instability, so these should only be used after careful consideration.
• Biokineticist: Once the pain and stiffness is under control, your rehabilitation program can be done in collaboration with a Biokineticist.
• Cortisone injections: Injections might sound like a good idea to improve your pain, this type of medication influences the integrity of all the tissues around your ankle joint, leaving you vulnerable to further injury.
• Orthotist: If you overpronate or have high arches, an orthotist can assist with inner soles or orthotics.

Surgery will only be considered if you haven’t achieved the desired outcomes after 3 months of non-surgical treatment. It is not a quick fix and will still require extensive rehabilitation to get you back to what you love doing, be it dancing, running or hiking.

A synovectomy can be done if the sheath around the peroneal tendons is damaged or inflamed.

The peroneal tendons may be repaired or replaced by a part of the Achilles tendon.

If you have peroneal tendon subluxation the groove on the fibula where the tendon runs can be deepened.

After the surgery you will be in a moon boot for at least 4 weeks to ensure tissue recovery before you can start gaining range of movement. Thereafter, you need to regain strength, control, and endurance until you can eventually get back to your sport.

• Lateral ankle sprain
  This usually causes immediate pain, some swelling and even bruising.
• Tarsal tunnel syndrome
  Characterized by tingling, numbness and pain into your foot.
• Sinus tarsi syndrome
  Inflammation of the structures around your ankle which leads to stiffness, difficulty walking on uneven ground and chronic pain on the outside of the ankle.
• Referred pain from your lower back
  Pain, pins and needles, numbness and/or weakness down your leg and into the ankle.
• Superior tibiofibular joint
  Knee injuries can affect this joint which can lead to pain at the outside of the ankle.
• Stress fracture
  Gradual onset of pain on the outside of your ankle that is aggravated by weight bearing and running.
• Complex Regional Pain Syndrome (CRPS)
  Symptoms of temperature change, flaky skin, skin discoloration, swelling without reason and stiffness.
• Avulsion fracture of the base of the 5th metatarsal
  A small piece of bone breaks away from the 5th metatarsal with swelling, pain and bruising along the outside of your foot.

• Peroneal tendinopathy
• Peroneus brevis tendon pain
• Lateral ankle pain
• Peroneus longus tendon pain
• Ankle tendon pain
• Peroneal tendon pain