The peroneal muscles (peroneus brevis and peroneus longus) lay on the outside of the lower leg; the two peroneal tendons travel side by side behind the outer ankle bone and down into the foot. The main function of the peroneal tendons is to stabilize the foot and ankle. The tendons also act in together to evert your foot (roll it outwards) and also help assist your calf muscles in plantarflexing your ankle (pointing your toes).
Peroneal tendon injuries often cause pain on the outside of your foot, outer ankle and/ or up the outside of the lower leg. Peroneal tendon injuries can affect anyone; often caused by overuse of the tendon or trauma (such as an ankle sprain). Peroneal tendon injuries are typically related to activities that involve repetitive ankle motion, as well as sports that involve frequent change of direction.
Peroneal tendonitis is classified as inflammation and swelling of the tendon; the terms peroneal tendinopathy results in tendon damage from chronic overuse. Both diagnoses are commonly associated with athletes and workers who repetitive stress the tendons, although peroneal tendonitis is the most commonly referred to.
Pain and stiffness - Pain on the outside of the ankle, especially with activity. Pain may be present along the length of the tendons or on the outside of the foot. Pain typically decreases with rest. The ankle may feel stiff upon first getting up after long periods of inactivity.
Feeling of weakness or instability in the ankle
Swelling - inflammation along the length of the tendon and behind the outer ankle bone isn't uncommon
A "snapping" sensation of the tendon around the affected ankle
Tenderness to the touch - typically behind the ankle bone on the outside of the ankle
Pain when pushing off the ball of the foot during walking or running
Pain when walking on sloped terrain
Soreness when stretching the foot in an inwards and downwards direction or when performing ankle circles (passively stretching the tendon)
What is happening to cause peroneal tendonitis?
Peroneal tendon injuries can occur due to a wide range of causes, but most commonly originate from overuse or a single traumatic event such as an ankle sprain.
Peroneal tendonitis is associated with repetitive ankle motion - this puts athletes and workers at risk. When one or both of the peroneal tendons are overloaded and not enough recovery is given, tissue breakdown occurs and the tissue becomes even less tolerable to loading. As the peroneal tendons help to support the foot, everyday activities such as walking put stress on the tendons. Certain foot types are most prone to increased stress on particular tendons. People with high arches put more tension on the peroneal tendons, predisposing them to injury. Those with flatfeet are also at risk of developing peroneal tendonitis as a flatfoot structure can impinge the tendons. Activities that are typically related to peroneal tendonitis are walking or running (particularly on uneven ground) or sports that involve frequent change of direction or jumping (such as basketball, soccer and dancing).
An ankle sprain or history of ankle sprains can lead to peroneal tendonitis. When your ankle is turned an awkward way the peroneal muscles may contract forcibly in an attempt to limit ankle injury, but his can injury the peroneal tendons. After an ankle sprain the peroneal tendons may be contracted to guard other injured tissues.
Potential Causes & Their Treatments:
Initially aim to calm down and settle symptoms by managing the load placed on the peroneal tedons (i.e. resting), and through treatments such as calf stretching, taping, icing, anti-inflammatory medication (if physician approved) and massage. Then identify and treat the potential cause(s). Anything that increase the load on the peroneal tendons above the level that it can tolerate can be a contributing factor to the injury, such as:
Overuse- Any change in your work environment or athletic regimen - such as an increase in distance, speed or a change in terrain could potentially cause peroneal tendonitis to flare up. It is important to allow your tissues to adapt to the increase in load. A change in job demands or training program can alter the stress placed on the tissue, and if the issue can't adapt injury occurs. Take a step back and reduce the stress placed on the tissue by resting or modifying activites.
Trauma - such as a fall or ankle sprain, some cases of peroneal tendon injury are precipitated by an ankle sprain.
Activities with lateral (side-to-side) movements and sudden changes in direction- avoid exercises that require sudden changes in direction and exercises with lateral movements. Choose activities that involve less intensity that will keep you active while encouraging a healthy recovery. Uneven terrain can have the same effect, stick to flat surface and avoid walking on pitches (graded roads. sloped roofs) and trails, until pain has improved.
Biomechanics/ Foot Structure- Individuals with high arches have a tendency to excessively load the peroneal tendons. A custom-made foot orthotic can reduce the stress placed on the peroneal tendons. In the opposite effect flatfeet can cause impingement the peroneal tendons. Orthotic support can help to provide a better base of support and increase ankle control minimizing overuse. An ankle brace can also be effective to control ankle instability and well as physiotherapy.
Tight Calves- Stretch out your calf muscles. Tight calves can cause a more rapid transfer of stress onto the midfoot, increasing the demand onto the peroneal tendons. If your calves are tight stretching out your calf muscles can help alleviate excess stress placed on the peroneal tendons. Do this by holding a standing calf stretch against a wall, both with a straight knee and a bent knee, for 3 x 30-seconds each, twice a day.
Muscle Weakness- Navigating uneven surfaces, requires significant ankle strength to avoid unnecessary stress on the ankle. Eversion (rotation your foot outwards) exercises against resistance using an elastic band can help build strength in the peroneal tendons. Increase the amount of repetitions and how stiff the elastic band is as you get stronger.
Poor fitting or worn out footwear- Worn out and improper fitting footwear can increase the tension on the peroneal tendons. Making sure you are wearing the appropriate footwear for your foot type and activity can reduce tension on the peroneal tendons and prevent reoccurrence. Running Style- Certain running styles such as those of forefoot and midfoot strikers place greater load on the peroneal tendons, potentially leading to overuse. Overstriding can have a similar effect. Leg Length Discrepancy - If peroneal pain is only present on one side, the possibility of a leg length discrepancy may need to be considered. Often times on the short leg the foot rotates outwards in an attempt to equalize the leg length, placing greater stress on the peroneal tendons. Seek out treatment from a variety of practitioners; a multidisciplinary approach can be effective at addressing the injury from multiple angles.