Soleus, the forgotten muscle for runners

by Jun 6, 2018Anatomy, Exercises, Health and Wellness, Injuries

Running is incredibly amazing for your brain, body and soul.

Studies have proven the remarkable health benefits of running. It boosts stamina, sharpens mental health, and provides countless perks for your total wellness.

However, sports injuries are common for runners. An example of this is calf strain, which heavily affects the gastrocnemius muscle and soleus muscle.

Triceps surae is the medical term for the calf muscle. It is made up of the medial and lateral head of the gastrocnemius muscle (the large visible muscle in the calf) as well as the more slender soleus muscle. The triceps surae connects to the Achilles tendon. A muscle strain can happen to any of the three muscle units.


The triceps surae, muscles located at the calf.

What is the Soleus Muscle?

Your calves are actually made of 2 different muscles: (1) your gastrocnemius (medial and lateral heads) and (2) your soleus. Both are powerful muscles responsible for plantar flexion (pointing your toe or standing on your tiptoes) and are vital muscles in walking, running, and keeping balance. The gastrocnemius is your larger calf muscle, forming the bulge that is visible beneath your skin. The gastrocnemius has two parts or “heads,” which combined together create its diamond shape. The soleus is your smaller, flat muscle that is often overlooked because it’s hiding underneath your gastrocnemius muscle.

The name is derived from the Latin word “solea”, meaning “sandal”. The soleus runs from just below your knee down to the ankle joint, attaching at the top of the tibia and fibula leg bones (at your knee) and inserting at the achilles tendon (by your heel).

Consisting predominantly of slow twitch muscle fibres that make it relatively resistant to fatigue, it is still occasionally used for explosive movements as well. A soleus muscle injury is more frequent in older athletes and often underestimated.

Soleus injuries are common for runners. Fatigue and overtraining are common injuries especially for long-distance runners. Soleus strain is also common to athletes who sprint including tennis and basketball players and other sports that require quick, sudden movements and jumping. Athletes are usually encouraged to do calf raise type exercises to prevent and minimize soleus injury.

There are three muscles in the posterior compartment of the leg which originates from the soleal line. The soleal line can be seen at the posterior surface of the tibia and tibial nerve. The most common muscle in the ankle is called accessory soleus muscle. The human anatomy shows that accessory soleus muscle develops at the medial border of soleus muscle and Achilles tendon.

anatomy of the soleus muscle

The anatomy of the soleus muscle, the soleus is hidden under the larger gastrocnemius

illustration of accessory soleus muscle

The accessory soleus muscle, located at the medial border of the soleus muscle and achilles tendon.

Why is it important for runners?

Did you know when you are running, your body has to support a load that is 3-8x your bodyweight? This is a lot of force exerted on those muscles. The calf muscles play a very important part to running and walking.

The plantaris muscle belongs to the posterior compartment of the calf muscles. The soleus muscle flexes the foot so that the toes point downwards; this is also known as plantar flexion. The soleus plays an important role in maintaining standing posture, making sure your body doesn’t fall forward. The deeper soleus muscle may not have the sprinting power that the outer calf (Gastrocnemius) has; but, these slow-twitch muscle fibres highlight its importance in long distance running. The soleus bears a lot of load during running, much more than the larger gastrocnemius muscle. Furthermore, the soleus is also often called the skeletal-muscle pump because it, along with the help of other calf muscles, pumps deoxygenated blood back from your legs to your heart.

For runners, the soleus: 

  • propels us forward during running and walking

  • bears most of the load from running

  • is very resistant to fatigue

soleus muscle

Why do my calf muscles get tight after running?

The commonly referred to calf muscles are responsible for forward propulsion movement of the lower extremity below the knee. The largest tendon in the body which is the Achilles tendon or calcaneal tendon connects the calf muscles down to the heel bone. This allows a person to stand, walk or run through a plantar flexor.

As we mentioned before, the soleus muscle absorbs loads that are much, much greater than your body weight each time you take a step while running. So why does your calf always feel so tight? If the soleus muscle fiber is not strong enough for the job, which gets increasingly harder the more running you do, the muscle is going to fatigue and strains of the gastrocnemius muscle, causing the protective tone that you feel as a lot of stiffness and soreness. So how do you fix it? Do some strengthening exercises such as a knee bent calf raise. A stronger soleus will be able to handle the tensile forces placed on it.

The peroneal artery supplies blood to the lateral compartment of the lower leg. The peroneal vein joins the posterior tibial vein. If a blood clot forms in the deep vein or deep vein thrombosis happens it results in cramping and leg pain. Also, red and discoloured skin may appear. Experts also stated that deep vein thrombosis and strains of the gastrocnemius have similar risk factors. Blood clots are extremely dangerous and if you suspect that you may have one, seek medical advice (hospital emergency department) immediately.

illustration of peroneal artery

Specialists also further discussed that the ankle dorsiflexion and inversion of our foot are facilitated by the tibialis anterior muscle. During physical activity and exercise, the blood flow increases which swells the muscles and thus causes pain.

On the other hand, the tibialis posterior muscle is the primary stabilizer of the lower leg. It also assists in the ankle plantar flexion (pointing your toe). Its key role supports the medial arch of our feet (the arch of your foot). If dysfunction occurs, it may lead to flat feet and foot pain in adults.

How Do I Make Mine Stronger?

A strong, powerful muscle can only be achieved when you engage strength training for resistance exercises aside from cardiovascular exercises such as running. This is also known as progressive overload.

Heel-raise or calf raise training with the knee bent is an effective muscle strengthening method for the soleus. You can employ double-leg calf raises and single leg calf raises. The best way to activate your soleus involves plantar flexion or pointing your toes downward, while your knees are in a bent (preferably at or around 90 degrees) position. Bent knees during heel raises target the soleus. If you do not bend your knees, the larger more powerful gastrocnemius muscle will be activated.

For some great exercises to target your soleus as well as how to stretch your tight soleus, be sure to check out the following videos!

How do you know if your calf muscles are tight or just weak?

Having a trained professional assess your range of motion and strength is a good way to determine the health of your calf muscles whether they are tight or weak.

This can be done by a registered physiotherapist. A registered physical therapist can assess other potential causes of calf or foot pain from running or other movements. Here at Westcoast SCI, we offer individualized running assessments with our registered physiotherapists who are running specialists and they will help you improve your running form and prevent injuries.

Westcoast SCI Port Coquitlam Physiotherapy also has its professionals who can assist runners in running assessments and in improving running gait, biomecanics, shed time of your races or even simply teach you how to run more safely, efficiently and effectively while decreasing the likelihood of injury.

Individualized Running Assessment

Are you an elite runner? Or taking up running for the first time? Find the best version of you by visiting Westcoast SCI and take advantage of our time-tested service for runners.

We offer an extensive running assessment which will thoroughly evaluate your gait, running style and biomechanics. The comprehensive running assessment includes one-on-one interviews to get the total picture of your running history including past injuries, lower extremity evaluation, self-selected pace treadmill evaluation and goal setting.

The goal of a running assessment is to evaluate your running technique and identify muscular imbalances and areas of your running form that can be corrected in order to improve your running performance and most especially to prevent injuries, particularly in the foot, ankle, knees, hips and back.

The initial assessment is broken into four stages namely: 1) Running history which is the gathering of information about your footwear, running distance and evaluation of your entire body. 2) Running analysis which is the checking of your cadence, stride length, biomechanics, arm swing and heart rate 3) Running review which discusses what tools and patterning need adjustments and 4) Running revision in which you will now receive the prescribed running exercises to address running impairments and weaknesses.


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