Peroneal tendonitis is an overuse injury causing inflammation and degeneration of the peroneal tendons resulting in pain on the outside of the ankle. Here we explain the symptoms, causes and treatment for peroneal tendonitis.
Peroneal Tendonitis Symptoms
Symptoms of Peroneal tendonitis/tendinopathy include:
- Pain and swelling on the outside of the ankle just below the bony protrusion (lateral malleolus).
- Pain is often worse during activity, but symptoms improve with rest.
- You may have pain when pressing in on the outside of the ankle.
- Pain may be recreated by stretching the peroneal muscles.
A professional therapist may perform a number of tests to help diagnose your injury.
- They will stretch your peroneal muscles. This is done by inverting your foot (turning it inwards). If this is painful then the test is positive.
- In addition they will stress your peroneal tendon. This is done by resisting movement as you attempt to straighten your ankle from an inverted position. If resisted movement is painful then this may also indicate the peroneal tendons are involved.
- An MRI or ultrasound imaging scan will help confirm the diagnosis.
What is Peroneal tendonitis?
The peroneal muscles
The Peroneal muscles consist of the Peroneus longus (long) and Peroneus brevis (short) at the back & outside of the lower leg. The bony bit on the outside of the ankle is called lateral malleolus. The peroneal tendons pass down the back and underneath the lateral malleolus. Overuse causes the peroneal tendons to rub on the bone and become inflamed.
The peroneus longus tendon runs around the back of the lateral malleolus and under the foot. It attaches to the outside of the first metatarsal and cuneiform bones.
The peroneus brevis also passes around the back of the lateral malleolus. It attaches to the outside of the foot at the base of the 5th metatarsal. The muscles act to plantarflex the foot (point foot downwards) and evert the foot or turn it outwards.
Tendonitis or tendinopathy?
The term Peroneal tendinopathy rather than Peroneal tendonitis may be more appropriate, especially in chronic cases. This is because it describes degeneration of the tendon as opposed to just acute inflammation. If your injury is quite recent, for example, a few days old, then you may have acute inflammation (tendonitis).
However, in chronic cases, acute inflammatory cells are unlikely to be present. Therefore, degeneration (tendinopathy) of the tendon is a more accurate description.
What causes Peroneal tendinopathy?
Overuse is the primary cause, however, there are a number of factors which can increase your risk of injury.
- If you run on along slopes which cause excessive inversion (rolling out) of your foot then you are more susceptible1. This is because the peroneal tendon is stretched more across the bone, therefore increasing friction.
- Tight calf muscles will increase the tension in the peroneal tendon, so causing it to rub more.
- Overtraining is also a contributory factor, particularly in dancers or basketball players.
- Biomechanical factors such as overpronation, or oversupination are factors, increasing friction between your tendon and ankle bone.
Peroneal Tendonitis Treatment
- Rest is important when treating peroneal tendonitis. As it is an overuse injury, continuing to train will now allow time for healing to take place. However, it may be possible to do other activities such as swimming or cycling to maintain fitness. The rule is if it hurts during, immediately after, or the following day then don’t do it!
- Cold therapy – apply the PRICE principles (protection, rest, ice, compression, and elevation). This will help reduce swelling, pain, and inflammation. Ice or cold therapy can be applied for 10 minutes every hour to begin with, reducing frequency as your symptoms improve.
- Ankle support/brace – wear a peroneal tendonitis brace to protect and support your ankle. If your injury has passed the acute stage then a simple neoprene ankle wrap is ideal as it acts as a heat retainer.
- Tape your ankle. This provides a great deal of support and protection to the ankle. It can be done in the same way as an ankle sprain taping technique.
- A doctor may prescribe NSAID’s (non-steroidal anti-inflammatory drugs) to reduce pain and inflammation. Do not take Ibuprofen if you have Asthma.
Peroneal Tendonitis exercises
Stretching your calf muscles and peroneal muscles are important. Tight peroneal muscles will increase the friction between the peroneal tendon and the bone. Gently stretching the muscles over time will reduce the tension in your muscle.
Calf muscle stretches
If you simply rest without stretching or addressing the initial causes, pain will go. However, it is likely to return once you resume normal training.
Peroneal muscle stretch
A specific stretch to target the Peroneal muscles is done by stretching your foot into an ‘inverted position’. This is more easily done in a sitting position.
Deep tissue sports massage to the peroneal muscles can help to reduce tension in the muscle. As a result, the muscles relax, which in turn reduces the tension in the tendon. In severe cases, surgery may be required. Massage techniques will be similar to those for a calf strain.
References & further reading
- Clarke HD, Kitaoka HB, Ehman RL. Peroneal tendon injuries. Foot Ankle Int 1998;19(5):280–8.
- Tjin ATER, Schweitzer ME, Karasick D. MR imaging of peroneal tendon disorders. AJR Am J Roentgenol 1997;168(1):135–40