Peroneal tendonitis may also be known as a tendinitis; tendinosis; tenosynovitis; tenovaginitis and probably a few more names as well! As with “Achilles Tendonitis” the best term to use is Tendinopathy as this is an umbrella term to cover all slight variations and does not suggest an inflammatory cause (more on that later).
What is Peroneal Tendonitis (Tendinopathy)?
The Peroneals are two muscles – Peroneus Brevis and Peroneus Longus which run down the outside of the lower leg. Both muscles originate from the outer aspect of the Fibula bone (smaller of the two shin bones). The Peroneus Longus starts from higher up – hence the name longus and the word Brevis meaning short.
Both muscles pass down the leg where the tendon then travels behind the outer ankle bone (lateral malleolus) in a groove formed by the malleolus and Talus / Calcaneus (heel bones). Peroneus Brevis has a shorter tendon which inserts into the base of the 5th Metatarsal on the outside of the foot. The tendon of the Peroneus Longus passes underneath and across the sole of the foot to insert into the base of the 1st metatarsal and the medial cuneiform (see foot anatomy here).
The function of the Peroneal muscles is to assist the Calf muscles in Plantarflexing the foot (pointing it down), whilst also everting the foot. This movement may also be known as pronating the foot – basically turning the sole of the foot outwards.
Symptoms of Peroneal Tendonitis (Tendinopathy)
- Pain around the outside of the ankle
- Tender to press the tendons just above and behind / below the lateral ankle bone
- Mild swelling may appear on the outer ankle
- Pain initially develops towards the end of a run and stops when you rest
- As the condition progresses the pain may be there at the start of the run and then ease off for a while before returning
- As the condition worsens still the pain is more constant – even in between runs
- Pain on pushing the foot outwards against resistance
What causes Peroneal Tendinopathy?
There can be a few causes but as with most running injuries it is an overuse injury caused my additional stress or wear on the tendons. As with most overuse tendon injuries, there is no longer thought to be an inflammatory element to the condition and so terms ending in ‘itis’ (which is a latin prefix for inflamed) are outdated. The pain is more likely stemming from degenerative causes, where the tendon develops a change in the normal arrangement of it’s collagen fibres. Some are torn and others become out of alignment which together weakens the tendon. Over time, scar tissue develops and the tendon becomes thickened and at a higher risk of rupturing.
Runners who oversupinate, or have a very high and rigid arch are most likely to develop this condition as the Peroneal muscles work harder to try to reduce this supination by pronating the foot.
Peroneal tendonipathy may also occur in those who overpronate however, because as well as acting to supinate the foot, the peroneals also work eccentrically (lengthening under tension) to control excess or rapid pronation.
Peroneal tendinopathy also commonly develops after ankle sprain injuries. This is either directly due to damage to the Peroneal tendons at the time of injury, or due to an unstable ankle in the weeks or months following which requires additional stabilisation from these tendons.
Treatment of Peroneal Tendinopathy
As with most running injuries the first step of treating Peroneal Tendinopathy is to rest from running and anything else which aggravates it. In order to help the tendon(s) recover it is advisable to wear supportive, cushioned footwear whenever you are on your feet. If you do have a significant problem with either overpronation or oversupination, your therapist may recommend orthotic insoles or apply a taping technique to help reduce the excess movement and allow the tendon to rest.
Your therapist may also apply other treatments such as a form of electrotherapy (maybe ultrasound or laser) to help accelerate the healing process and they may also apply sports massage techniques.
Sports massage can be used directly to the Peroneal muscles to help reduce tension which usually develops in the muscles as a response to injury. Friction massage techniques can also be applied to the tendons themselves to help encourage a healing response. This works by increasing the blood flow to the tendons and breaking down excess scar tissue and adhesions in the tendons.
As soon as it is comfortable to do so, you should start strengthening the Peroneal muscles. Strengthening helps the collagen fibres within the tendon to realign and also helps develop the strength needed for running.
Start with isometric exercises which are static contractions. An easy way of doing this is to sit on the ground with the legs out straight on the insides of a chair (with 4 legs – important!). Position the front two chair legs on the outsides of the feet. Push outwards with the feet, into the chair legs so there is no movement, but the muscles are contracting. Hold for 5 seconds, rest and repeat 5-10 times initially. This should only be performed if there is no pain. If it is painful, rest and try again in a few days.
The next step on is concentric strengthening which can be achieved using rehab (resistance) bands or ankle weights. With a band, tie it in a loop and place it around the balls of the feet. Turn both feet outwards at the same time, against the bands resistance. Always do band exercises slowly and under control, especially on the way back to the starting point. Again this should be done without pain and with low reps to start with, which can be built up every couple of days. For examples, start with 12-15 reps, build to 25.
Concentric Peroneal strengthening can be achieved with ankle weights which should be wrapped around the forefoot. Lay on your side with the foot to be worked on top and turn the foot out so the toes point towards the ceiling (keep the ankles and heels together).
The final stage of strengthening is eccentric which is the hardest type of contraction for a muscle and really important when running to slow the pronation force on the foot. This is harder to do yourself, but with a partner is pretty straightforward. Sit on the floor with both legs out straight. The partner pronates (inverts) the foot so the sole of the foot faces inwards. As they do this, you try to slow them down. Don’t resist the movement completely, but just aim to control it. The stronger you get, the harder they can push! This is really hard on the muscles and tendons so definitely start with low rep (around 8-10 initially).
It’s quite difficult to stretch the Peroneal muscles so personally I don’t worry about this. If you are having massage treatment then this is going to be just as, if not more effective than stretching for this injury.
I would however, recommend stretching the calf muscles daily. This is especially important if you overpronate as tight calf muscles can contribute to this and place more strain on the Peroneal tendons.
Whilst the tendon is resting, this is the ideal time to look at what might have caused you to develop the condition and what you can do about it to stop it coming back.
If you haven’t had a gait analysis I would highly recommend this for Peroneal injuries as they are so closely involved with foot biomechanics. This will make sure you are wearing suitable running shoes and determine if you maybe need additional insoles or orthotics. Or, if you have been running for a long time and not had your gait reassessed in a couple of years, then it is worth getting it checked again as things can change.
If you have old trainers it may be time to replace them as the support and cushioning will have worn out. 400 miles is the rule of thumb for when to change your running shoes.
If this is all ok, take a look at your running program. Were you dramatically increasing mileage? Had you changed your route or added in more hill runs etc? Running on a road with a slant (so that one side is lower) could cause these problems.
If you’re struggling to find a reason for the injury, then I would recommend consulting a running coach to get them to look at your training plans and running technique. An experienced eye may be able to spot something you have missed.
Return to Running
Only return to running when completely pain free on a daily basis and once you are confident you have identified and addressed any causative factors.
Start with a very short jog (10 mins e.g.) and then have 2 days rest. Provided there is no recurrence of symptoms, then try another 10 minutes followed by another 2 days rest. If still ok, start to progress your running time, by 5 minutes at a time, running 2-3 times a week and only increasing every other run. Continue with this until you are back to your normal times / distances.