Soleus, the forgotten muscle for runners
What exactly is the Soleus?
Your calves are actually made of 2 different muscles: (1) your gastrocnemius and (2) your soleus. Both are powerful muscles responsible for plantar flexion (pointing your toe) 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 behind your gastrocnemius.
The name is derived from the Latin word "solea", meaning "sandal". The soleus runs from just below your knee to your heel behind your leg, 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. Injury in the soleus muscle is more frequent in older athletes and often underestimated.
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 body weight! This is a lot of force exerted on those muscles. The calf muscles play a very important part to running and walking. 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. The soleus is also often called the skeletal-muscle pump because it, along with the help of other calf muscles, pump deoxygenated blood back from your legs to your heart.
For runners the soleus:
- The soleus propels us forward during running and walking
- Bears most of the load from running
- Is very resistant to fatigue
Why do my calf muscles get tight after running?
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 is not strong enough for the job, which gets increasingly harder the more running you do, the muscle is going to fatigue causing the protective tone that you feel as a lot of stiffness and soreness. So how do you fix it? Make it stronger. A stronger soleus will be able to handle the tensile forces placed on it.
How Do I Make Mine Stronger?
Heel-raise training is an effective muscle training method for the soleus. 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 knee's during heel raises targets the soleus. For some great exercises to target your soleus be sure to check out the following video!
How do you know if you calf muscles are tight or just weak?
Determining if your calf muscles feel tight after running, because they are actually week or if they are shortened can be tested by assessing your range of motion. This can be done by a physiotherapist. A physiotherapist can assess other potential causes to calf or foot pain from running. Here are WestcoastSCI, we offer individualized running assessments with our physiotherapists that are running specialists.
Individualized Running Assessment
Whether you are a elite runner or new to running, in our running assessment we will evaluate your gait and running form on a treadmill. The goal of a running assessment is to evaluate your running technique and identify muscular imbalances and area's of your running form that you can correct in order to improve your running performance or prevent injury.
Click to read more about the individualized running assessment