Muscle Of The Month: Peroneals

The peroneals are a group of muscles found in the lower leg, specifically the fibula, which is why they are also often referred to as the fibular or fibularis muscles. There are three muscles in this group: peroneus longus, brevis and tertius.

Supporting the movement of the foot, these muscles can be prone to overuse, leading to peroneal tendinopathy, which is characterised by pain and swelling in the peroneal tendons.

The origin and insertion of the peroneal muscles

The peroneal muscles become tendons in the lower leg and insert into the metatarsals, which are between the ankle and toe bones.

The peroneus longus starts at the top of the fibula and connects to the first metatarsal and the medial cuneiform bone, while the peroneus brevis starts lower on the fibula and connects to the base of the fifth metatarsal. The peroneus tertius originates at the back of the third quarter of the fibula and inserts into the shaft and base of the fifth metatarsal.

The action and basic functional movement of the peroneals

The muscle group helps the foot move, particularly around the ankle joint, and supports us when we stand, whether on both legs or just one.

Both the peroneus longus and brevis allow the foot to bend downwards and twist outwards. Additionally, the peroneus longus supports the longitudinal and transverse arches of the foot.

The peroneus tertius is a small muscle that can vary in size and is sometimes absent in individuals. It lifts the foot upwards and twists it outwards.

What is peroneal tendinopathy?

The condition occurs when the peroneal muscles have been overused, resulting in symptoms such as a painful ache or swelling on the outside of the ankle. You may also experience pain when pointing your foot, moving it inward or outward, or pushing off the ball of your foot while walking or running.

Peroneal tendinopathy is common among athletes and sports professionals, particularly long-distance runners, dancers, and basketball players, as well as individuals with weak ankles or those who have suffered an ankle injury, such as a sprain.

How is peroneal tendinopathy treated?

Early diagnosis is crucial, and the initial stage of treatment typically involves rest. Continuing to walk or run will only exacerbate the condition. It’s then advisable to consult a physical therapist.

A physical therapist can assist you in the following ways:

• Assessing your posture, ankle strength, foot mobility and footwear
• Asking about your regular activities that involve specific motion (job, hobbies, sports)
• Establishing which movements you should avoid while the tendons heal
• Recommending treatments such as ice packs or ultrasound
• Using manual therapy to increase mobility in the areas around the injury
• Recommending exercises that stretch and strengthen the ankle, foot and leg to improve mobility and stability, including preventative measures
• Advising on the best footwear for you, including orthotics, e.g., shoe inserts, if required

Other treatments that can help include swimming, which will strengthen the ankle without putting weight on it. After a while, you can gradually build up to walking and running faster and for longer.

How can we prevent peroneal tendinopathy?

Wearing the correct supportive footwear for everyday and sporting uses can help prevent this condition. In some cases, you may benefit from using orthotics.

Specific exercises to strengthen these muscles can also help.

Exercises to strengthen the peroneals

These include:

• Standing calf raises – either with feet flat on the floor or standing with the toes on the edge of a step
• Resistance bands – loop under the arch of the foot and flex the foot to strengthen the muscles
• Lunges onto a half balance ball or wobble balance board
• Heel walks

If you are suffering from peroneal tendinopathy, it’s advisable to consult a medical professional and a personal trainer or fitness instructor before undertaking strengthening exercises.