Runners have to accept that playing their favorite sport comes with some risks. Among those training for a marathon, trail, or even a 5K race, injury rates are quite high. And there is always a chance that you will become one of the many runners who suffer an injury.
Runners often experience something like runner's knee or Achilles tendinitis. But what if the pain you're experiencing doesn't correspond to any of the common injuries among runners?
Peroneal tendinitis, also known as peroneal tendinopathy, is a rare but annoying injury. It can cause pain on the outside of your foot that radiates up your shin when you run.
What are the peroneal tendons?
Although peroneal tendonitis is not as common as other types of tendon injuries, this does not make it any less annoying. Especially if you can't pinpoint the source of the pain.
There are actually two peroneal tendons (one belonging to the peroneus longus and the other to the peroneus brevis) that are parallel to each other.
The peroneal muscles act in concert to turn the foot outward (eversion) and also help the gastrocnemius muscles flex the toes. They also help stabilize the ankle while walking and running.
As with all cases of tendinitis, the real cause of the problem is degeneration and damage, not inflammation, of the tendon. Thus, a more correct term would be “peroneal tendinopathy” or “peroneal tendon dysfunction.”
However, since the term “tendinitis” is more common, we will use it in this article.
Diagnosis of the disease
The main condition for successful treatment of quadriceps tendinosis is accurate and timely diagnosis. The primary stage includes a physical examination, during which the doctor will examine the area of the suspected lesion, compare mobility in both limbs, and determine the nature and intensity of pain.
For a more accurate diagnosis, laboratory and instrumental research methods may be needed. Laboratory methods for diagnosing tendinitis include:
- General blood analysis. Leukocytosis may indicate a bacterial infection causing inflammation of the tendon.
- Blood chemistry. An increase in uric acid levels may indirectly indicate gouty tendon damage.
- C-reactive protein test. Its presence indicates an acute inflammatory process and the infectious nature of tendinitis.
Instrumental diagnostic methods for hip tendon inflammation include:
- X-ray of the affected area to identify calcifications in the tendon tissue;
- Ultrasound is used primarily when traumatic tendonitis is suspected to identify micro-tears in tendon tissue;
- CT and MRI are used for more accurate diagnosis if the prescribed treatment is not effective enough.
How common is peroneal tendinitis among runners?
Like any other tendon, both peroneal tendons can be damaged by repeated activities that place stress on them.
Unlike Achilles or patellar tendon injuries, which are quite common and well studied, peroneal tendon injuries are quite rare.
In a study that classified the injuries of more than 2,000 runners at a specialist sports clinic, only 13 cases of peroneal tendinitis were found. This means that this injury accounts for only about 0.6% of all running injuries. With such a small number of cases, it is difficult to draw sufficient conclusions, however, 9 of the 13 diagnoses of peroneal tendonitis were made in male athletes.
It is difficult to say whether peroneal tendinitis is more common in men than in women. Or is it just a coincidence. But Achilles and patellar tendon injuries are more common among men. So maybe there is something to this trend.
What are the symptoms of peroneal tendinitis?
Peroneal tendonitis is characterized by sharp pain along the entire length of the peroneal tendons on the outside of your foot.
Tendonitis can develop at the tendon insertion point, in the area of tendon along the outer edge of the fifth metatarsal bone, or further down the outside of the ankle.
Running will cause pain, as will trying to bend your toes or turn your foot outward, especially if you have to overcome resistance. There may be some ankle stiffness and soreness when trying to rotate the foot or even when doing a calf stretch.
You should not experience much pain when standing or when you gently press on the injured area. If the outside of your foot is very sensitive to touch, and if you experience severe pain even without putting weight on your foot, you may have a fifth metatarsal fracture.
The latter is an unusual injury for a runner, but can be a serious problem if not treated promptly. So if you are unsure what is causing your pain, see your doctor as soon as possible.
Does it matter which of the 2 peroneal tendons is damaged? From the relatively sparse scientific literature on peroneal tendonitis, it seems that it is not important.
In fact, in about 33% of cases, peroneal tendonitis appears to affect both tendons. Therefore, any rehabilitation program should focus on treating both the peroneus longus and peroneus brevis tendons.
Symptoms of the disease
Inflammation of the hip joint is characterized by the presence of several local symptoms. The main one is pain of varying degrees. At the initial stage of the disease, pain in the hip joint appears only during intense physical exertion. After their completion, the painful sensations disappear.
With disturbances of 2-3 degrees, pain begins to manifest itself even in a calm state. In this case, disturbances appear in the motor system. In advanced conditions, there is a complete lack of mobility in the joint. Complications such as arthritis or arthrosis may also appear. In addition, the following symptoms may appear:
- swelling and redness of the skin;
- increased body temperature;
- crunching in the damaged area;
- shooting pain.
Experts also say that inflammation of the hip joint can be accompanied by numbness of the lower extremities and lower back pain.
Depending on the pattern of pain, tendonitis is divided into acute and chronic. The chronic form is less dangerous and is characterized by wave-like manifestations of symptoms. The pain appears suddenly and goes away just as quickly. In case of chronic disorders, a state of remission is not observed.
Causes of peroneal tendonitis in runners
Because peroneal tendonitis is so rare, there have not been any large-scale studies of risk factors for its development. The few studies have analyzed relatively small numbers of cases.
However, one risk factor seems to stand out from the rest.
A review of 22 cases of peroneal tendinitis by Clayton Brandes and Ronald Smith found that more than 80% of these patients had high arches. According to the authors, a higher arch puts a higher tensile load on the peroneal tendons, predisposing them to injury.
This makes sense because having a low arch appears to be a risk factor for injury to the tibialis posterior tendon, located on the inside of the ankle.
A study published in 1993 indicates that fast running tempos can also increase stress on the peroneal tendons.
Lyle Reber, Jacqueline Perry and Marilyn Pink from California examined how activation of the muscles surrounding the ankle changed as a result of changes in running speed in a group of healthy long-distance runners.
The researchers found that faster running speed significantly increased activation of the peroneus brevis muscle. The intensity of muscle contraction doubled when running at an easy pace versus running at a competitive pace.
Reber, Perry, and Pink proposed that the rapid transfer of load to the midfoot during high-speed running and the concomitant increased need for ankle stabilization are responsible for the increased activation of the peroneus brevis muscle.
This suggests that faster runners and those who do high-intensity interval training are at greater risk of developing peroneal tendonitis.
In some cases, damage to the peroneal tendon can be caused by an ankle sprain. This is not surprising given the location of the peroneal tendons in the foot.
A 1993 report by Mark Sobel, Mark Geppert, and Russell Warren traced a link between ankle instability resulting from previous ankle sprains and peroneal tendon injury. This connection was confirmed in a paper by Mayo Clinic researchers in 1998.
If you suffer from lingering pain after an ankle sprain, you may also have injured one of your peroneal tendons. Maybe they even tore it. This can be detected using MRI.
Reasons for development
The pathology in question can act as an independent disease, but it can also relate to the consequences of other problems in the body. Most often, doctors note that tendinitis occurs after excessive physical exertion or due to sports injuries. And often the patients themselves become the “culprits” for this - they begin intensive training with unprepared muscles and tendons. For example, symptoms of Achilles tendonitis occur after long runs when you want to lose excess weight - excessive zeal for positive results always ends sadly.
If the disease in question belongs to secondary pathologies, then it can be provoked by:
- improper metabolism;
- weakened immune system;
- rheumatism in different stages of its course;
- infectious diseases, for example, streptococcal etiology;
- gonorrhea;
- chlamydia.
Doctors emphasize that secondary tendonitis can develop only against the background of unstable immunity.
How to treat peroneal tendinitis?
When it comes to treatment, the rarity of the injury again complicates the situation. Since there have been no controlled clinical trials of the rehabilitation program.
However, we can draw some conclusions from what we know about trauma and follow the recommendations of scientists and doctors with clinical experience.
According to Daniel Heckman of the University of North Carolina, treatment should include rest (obviously), stretching and strengthening exercises, and proprioceptive exercises to restore proper tendon function.
From what we know about the function of the peroneal tendons, it follows that any strengthening exercise program should include turning the foot outward against resistance, perhaps using a rubber band.
A similar program was proposed by Alvarez et al. We adapt it for the treatment of peroneal tendinitis, focusing on turning the foot with the sole outward.
The program includes performing 200 repetitions of the sole-outward foot rotation exercise daily. You should start with a very weak resistance band and take breaks if necessary.
Over time, you should be able to complete all 200 reps without rest and switch to using a stiffer band.
When it comes to stretching, your best bet is calf stretches. Because tight calves can cause the load to shift to the midfoot more quickly during running, which increases stress on the peroneal tendons.
You can do calf stretches with your leg straight and your knee bent for 3 sets of 30 seconds, 3 times a day.
Single-leg balance exercises are the best way to improve proprioception and restore proper function of the peroneal tendons.
As with any balance training program, you can start by simply balancing on one leg and then move on to more complex movements that include bending forward, left, and right until your hand touches the floor. Or you can balance on a wobble board or a soft, thick foam mat.
A balance exercise program should be structured and include progressive exercise to improve proprioception.
When you're just starting out, work on maintaining your balance on one leg until you can do it for 2.5 minutes.
After this, you can begin to increase the difficulty by closing your eyes, bending your body, or using a wobble board.
What other treatment options are there?
As with any tendon injury, you may find cold applications or contrast baths helpful for peroneal tendonitis. Although there is no research data to support either of these options.
If rest and exercises to improve balance, stretching and strengthening do not resolve the problem, you should consider seeing a physical therapist.
You may have some unique biomechanical issues that are contributing to your case of peroneal tendinitis. Or you may need a different set of exercises.
If this is just one of the injuries you have, your running technique may be to blame.
One of the main reasons why running ends in injury is overstriding (placing the foot in front of the body's center of gravity).
Heckman and Selmani suggest using custom orthotics to relieve stress on the peroneal tendons.
Unlike many other injuries, it appears that in the case of peroneal tendonitis there should be a difference between custom insoles and standard insoles such as "SuperFeet" or "PowerStep".
Typically, the purpose of using an insole is to support the arch of the foot and shift the load to the outside of the foot.
This can be very helpful for injuries such as plantar fasciitis or splint splints. But in case of peroneal tendinitis, this may not be the best idea. Remember that more than 80% of people with peroneal tendinitis have high arches.
Supporting the arch even more and shifting the load to the outside of the foot (where the peroneal tendons are located) can actually make the problem worse!
Custom orthotics may be thinner at the arch of the foot and thicker under the outside of the heel. All of these can take pressure off the outer midfoot area.
If your case of peroneal tendonitis does not respond to rest and physical therapy exercises, custom orthotics may be worth a try.
If conservative treatments don't work, you may want to see an orthopedist and get an MRI to check if the tendon is torn.
Especially when a peroneal tendon injury occurs at the same time as an ankle sprain, there is a chance that it is not tendinitis, but a tendon tear that needs to be repaired surgically.
Fortunately, MRI is an effective method for determining the extent of peroneal tendon damage. If the tendon is torn or very seriously damaged, you may need surgery.
Conservative treatment
These methods are quite simple, inexpensive and can be used at home.
- Calf stretch
- Turning the foot with the sole outward with a rubber band
- Balance exercises
Aggressive treatment
These methods are more expensive and less likely to guarantee positive results, but may be useful in some cases.
- Contact your podiatrist or podiatrist to learn about getting custom orthotics. In the case of peroneal tendinitis, standard insoles will most likely not be as helpful due to the biomechanics of the injury.
- Consider trying dry needling. Some runners find that this works great for treating peroneal tendons. If you're desperate, it might be worth giving this method a chance.
- See a physical therapist who is familiar with running injuries to make sure you don't have any weak or tight muscles or running stride abnormalities that are causing tendon problems.
- If conservative treatments still don't work after several weeks or months, see your orthopedist for an MRI to check if you have a rupture or serious damage to the tendon, and possibly discuss the possibility of surgery.