The Peroneus Brevis tendon inserts into the 5th metatarsal bone on the outside of the foot. A strain or rupture of the tendon can occur at the point of insertion. This foot injury normally occurs after a sudden force or movement of the ankle, causing pain on the outside of the foot. Read more for symptoms and treatment of this injury.
On this page:
- Causes & anatomy
Peroneus Brevis tendon rupture symptoms
Symptoms include pain over the prominent bony part on the outside of the foot. The pain will most likely have come on suddenly after a twisted ankle or sudden forceful movement of the ankle.
There may be bruising and swelling and the foot will be painful to walk on. Pain will be worse when stressing the tendon by attempting to evert the foot or turn the sole outwards, particularly against resistance.
Peroneus Brevis tendon rupture explained
The peroneus brevis muscle plantar flexes and everts the foot, or pulls the toes up and the foot outwards. Its tendon attaches to the fifth metatarsal on the outside of the foot.
The end of the fifth metatarsal can be felt as the bony prominence on the outside of the foot. The peroneus brevis muscle can get very tight in runners, especially those who run a lot on roads.
Peroneal tendon ruptures usually happen following a traumatic event, such as an ankle sprain. Acute injuries to this tendon can be either tears or avulsions. An avulsion occurs when a muscle force is so strong that it pulls off a section of bone at the attachment point. A tear of the tendon can be partial or complete. Most tears are actually longitudinal, along the length of the tendon.
Treatment of peroneus brevis tendon rupture
Apply ice or cold therapy as soon as possible after injury. Ice can be applied for 10 minutes every hour and reduce the frequency as required, although a minimum of 3 times a day is often recommended. This will reduce pain and inflammation and help limit swelling, which may delay the healing process. Ice should not be applied directly to the skin but in a wet tea towel, or use a commercially available hot and cold pack.
Rest is important for at least 48 hours while the acute stage of the injury passes. Continuing to limp about on the foot will only delay recovery. After the acute stage has passed very gentle stretching can be done if pain allows.
See a sports injury professional who can make an accurate diagnosis and rule out an avulsion fracture. An avulsion fracture is where the tendon has come away from the bone and possibly pulled a piece of the bone with it.
A doctor may prescribe anti-inflammatory medication such as ibuprofen, which may help reduce pain and inflammation in the early stages. Do not take ibuprofen if you have asthma and always check with a doctor before taking any medication.
Electrotherapy such as ultrasound or laser treatment may also reduce pain, inflammation and stimulate the healing process. For a severe tendon strain or an avulsion strain, a plaster cast may be used if necessary while the injury properly heals.
Once the injury has healed, the foot and ankle should be rehabilitated with stretching and strengthening exercises. Exercises similar to those of an ankle sprain are appropriate. Initially, isometric, or static exercises can be done with a therapist or partner providing resistance. Everting the foot against a resistance band will specifically strengthen the peroneal muscles.
The aims of rehabilitation of a peroneus injury are:
- To decrease the initial pain and inflammation
- Improve flexibility
- Build strength and neural coordination of the joint
- Gradually return to full sports specific fitness.
Improve mobility and flexibility
Stretching exercises for the calf muscles, and in particular the peroneus brevis muscle, should begin as soon as pain will allow. This may be 48 hours after a minor strain or up to a week or more for a more severe injury. If it hurts to perform any of the exercises then wait longer until there is no pain.
Stretching the muscles at the back of the lower leg is important. Stretching with both a straight and bent leg will ensure the Peroneus Brevis and Soleus muscles are also stretched properly. Perform stretching exercises gently 2 to 3 time a day, applying ice or cold therapy after stretching in the early stages of rehabilitation to help reduce any resulting inflammation.
Peroneal muscle stretch: The ankle inversion stretch, or peroneal stretch, specifically targets the peroneus
Gastrocnemius & Soleus stretches: Gastrocnemius – place the leg to be stretched behind and lean forward against a wall or fixed point, ensuring the heel is pressed in contact with the floor at all times. A stretch should be felt at the back of the lower leg. If it isn’t then move the leg back further. Hold the stretch for 20 to 30 seconds and repeat 5 times. Repeat daily. The stretch should not be painful, relax into it. If you experience pain, particularly at the front of the ankle, then take a step back and rest. If you still cannot feel a stretch then stretching on a step may be more appropriate.
Soleus – this exercise stretches the lower calf muscle called the soleus. In order to stretch the soleus muscle, the knee of the stretching leg needs to be bent to eliminate the large gastrocnemius muscle for the stretch. One leg should be placed behind with the knee bent and lean against a wall bending the knee and keeping the back heel in contact with the floor. A stretch should be felt lower at the back of the leg. If not then an advanced version of this can be done by placing the forefoot against the wall in front with the heel on the floor and push the knee towards the wall. Again, hold for 20 to 30 seconds and repeat 5 times. Repeat daily.
Strengthening and proprioception
Strengthening exercises can begin as soon as they can be performed without any pain. This is likely to be at least a week for most injuries. It is far better to delay loading the injured tendon a bit longer than may be necessary rather than overloading it too soon and making the injury worse.
Strengthening exercises should be done for all ranges of movement of the ankle, not just for the area of injury. This will ensure good all-round strength and help to prevent further injuries. It is important to maintain fitness by swimming or cycling if pain allows, or take the opportunity to work on upper body strength.
When the ankle or foot is injured, often the proprioception (or coordination) of the joint is also damaged, making it less stable in future. Specific ankle exercises to restore proprioception should be done. These include balancing exercises, such as balancing on one leg with the eyes closed or using a wobble balance board. Using a balance board will strengthen the ankle and improve proprioception at the same time.
Strengthening the peroneal muscles and other supporting ankle muscles, as well as improving the proprioception or co-ordination of the ankle, is important in the rehabilitation of a peroneus brevis tendon injury.
Static eversion ankle exercise: These exercises will specifically strengthen the muscles that stop the ankle from being turned over or inverted, including the peroneus brevis muscle. Static exercises, also called isometric exercises, are where the joint does not actually move during the exercise. Rather, the muscle contracts against an immovable resistance such as a wall, chair or partners hands. Hold for 5 seconds, rest for 3 seconds and repeat until you feel the muscles working. This exercise can be alternated with static inversion strengthening to balance the ankle out.
Dynamic eversion exercise : The second exercise will strengthen the muscles dynamically, or when moving, and can be done as long as pain allows and when 3 or 4 days of isometric or static exercises have been done. Using a resistance band or equivalent, the foot is turned outwards against resistance, working the peroneal muscles on the outside of the calf. Resistance can also be applied by a partners hands. Start with 3 sets of 10 reps and build up. The exact number of reps will vary depending on the amount of resistance and the strength of the ankle. Aim for high reps, low resistance in the early stages.
Calf raise exercise: This exercise will strengthen the calf muscles, which consist of the gastrocnemius muscle and the soleus muscle. This exercise can be performed against a wall or on a step. Rise up and down on the toes in a smooth movement. You should be able to progress quite quickly with this one but aim for 3 sets of 10 and build up steadily, a few each day. A beginners version of this exercise can be done in a seated position. This works the soleus muscle more than the larger gastrocnemius muscle.
Front of the ankle strengthening: This exercise works the dorsiflexors, or muscles that pull the foot upwards. Using a rehabilitation band pull the foot and toes up against resistance and then down again. Aim for 10 to 20 repetitions and 3 sets with a short rest in-between. This is an important strengthening exercise, however, it is important not to overdo this one. Remember you will still have to walk on the ankle after the strengthening session so do not take the ankle to fatigue. Over time this may also lead to pain in the front of the shin – less is probably more with this exercise.
Return to full fitness
When the athlete can comfortably do all of the above and has progressed through specific ankle and wobble board exercises, then you are ready to start the next phase and begin to return to activity. They may begin running as long as it is not painful starting with a gentle jog and gradually building up until they can run pain-free for 20 minutes before increasing the speed or introducing fast changes of direction.
Gradually introduce sideways or lateral movements, and then progress to agility runs involving changes of direction with increasing speed. If there is any pain either during, after or the next day then apply ice, calm things down and take a step back before progressing.
Continue with stretching, strengthening, and balance board exercises for a few weeks throughout the rehabilitation program and for a few weeks after full sports specific training has resumed.