Calf muscle Series Part 1: What They Do Plus Common Injuries

WHAT ARE THE CALF MUSCLES?

The calf muscles, as they are typically referred to, make up the back part of our lower leg. They begin at the rear of our knee and insert into the back of our heels.

The calf muscles AKA Triceps Surae (yeah bro you have a triceps in your calf) are made up of:

1. Gastrocnemius – this is the most superficial of the calf muscles and it has 2 heads: medial (inside) and lateral (outside). This makes up a single large muscle (smaller in some?) and this muscle plantarflexes the ankle and assists in flexing the knee.

2. Plantaris – woah, hang on! Bet most of you have never heard of this muscle before. Well here’s a fun fact: about 10% of you actually don’t have one. Its actions are the same as your gastrocnemius however it’s not so vital for these movements.

3. Soleus – The soleus is the located below the gastrocnemius. This muscle actually originates below the knee, so it has no action as a knee flexor and then joins the calcaneal tendon with the gastrocs to insert into the heel bone. Soleus is used constantly in standing to maintain an upright position.

When these muscles combine, they form Captain Planet! Just kidding, they actually form the Achilles tendon (calcaneal tendon) which inserts into the heel bone. The Achilles tendon is the largest and strongest tendon in the body, but despite its strength its also susceptible to injury. Below are some of the most common injuries that occur to the calf and Achilles.

PATHOLOGY

Calf muscle injuries:

• • Calf muscle strain – stretching of the muscle past its normal length results in the tear of some fibres. This could also be known as a “pulled muscle”, which can vary in severity.

• • Calf muscle tear – all strains result in the tearing of some muscle fibres, however more serious injuries result in partial or complete tears.

• • Calf muscle ruptures – complete tear of the calf muscle resulting in severe pain and the inability to walk or stand on the leg. In some cases this can be visibly seen as a big ball in the leg. The treatment will differ depending on the severity of the rupture. For example, a Plantaris rupture might hurt like hell but can be managed with immobilization, however a gastrocnemius rupture may require surgical intervention.

Achilles injuries:

• • Achilles tendon tear – Can be small or large, resulting in pain, the inability to move or stand on your leg.

• • Achilles tendon rupture – a complete tear may make a “pop” sound followed by swelling and pain. In this case you want to get to a specialist ASAP!

• • Tendinopathy – a general term for tendinosis and tendinopathy. For argument sake lets just refer to it as an overuse injury to the tendon with or without inflammation. 

• • Achilles bursitis – inflammation of the fluid sac which cushions the Achilles tendon at the heel.

In order to keep the calf muscles and Achilles tendon in good shape and prevent injury, it’s important to make sure you stretch and strengthen them. Next week we will look at some of my favourite stretches and strengthening exercises that you can add to your routine to prevent injury in the first place, or use during your recovery as advised by your physio.

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