Time for a super sexy blog topic: the soleus muscle! It’s really more of a sexiness-by-comparision, since an injured soleus can cause shin splints, Achilles tendonitis, plantar faciitis, and tibial stress fractures—none of which I find sexy at all. AT ALL.
A TALE OF TWO CALF MUSCLES
I love a well-developed calf muscle (who doesn’t?). But usually when we talk about the calf, we’re talking only about the calf muscle closest to the surface of your skin: the gastrocnemius. The gastroc is a plump, two-bellied muscle that runs from your heel to just above your knee—its name in Latin means “stomach of the leg,” since it bulges outward like a cute little beer gut. It’s the muscle we see defined in the lower legs of football players and dancers and cyclists and basically any athlete who sprints, jumps, or changes directions quickly. When we think “calf muscle,” we think gastroc (even if you didn’t previously know its name). The soleus muscle, on the other hand, lies deep to the gastroc and goes relatively unnoticed and underappreciated—which, when you’re an athlete, can cause some major problems.
The problem with the soleus muscle is that it lives in obscurity compared to its glam partner, the gastroc. Running from your heel to just below your knee, the soleus assists in many of the movements the gastroc does—jumping, sprinting, pointing your toes, etc. But unlike the gastroc, the soleus is made up of mostly slow-twitch muscle fibers, which helps it function as a stabilizing postural muscle. While the gastroc does the fast-twitch work when it’s time to sprint to first base, the soleus does the slow-twitch work to keep you from tipping forward when you’re standing in the dugout waiting to bat. We need the soleus for walking and standing—two pretty un-sexy movements, sure, but definitely crucial for human performance. And it’s for this reason that the soleus is the stronger calf muscle: it needs to be! After all, we stand a lot more than we jump (or, at least, I do). So now that we realize just how important this unsung muscle is, let’s talk about how it can really mess you up when it’s injured.
SHIN SPLINTS AND STRESS FRACTURES?!
I recently got back into distance running after a two-year hiatus. After about 3 months of running the same loop, on pavement, most days of the week, I went to see my massage therapist/good friend, Allison. I told her my calves had been pretty tight—and she dug into the muscles around my shin with her fingertips. I nearly jumped off the table. The muscle that ran along the inside of my tibia was bumpy—Allison said massaging it felt like "reading braille"—and I could not contain the litany of inappropriate-for-blog words escaping from between my gritted teeth, it hurt so bad.
“Girl, you’ve got some shin splints going on,” she said.
“Huh?” I said. I, an experienced runner, dealing with shin splints? Not only is it a condition commonly attributed to newbie runners, I had always thought it affected the outside muscle of the shin, the anterior tibialis. The muscle Allison was tearing apart was my posterior tibialis.
“Yep,” she said. “We are gonna need to stretch your soleus.”
Anything but this torture. “My calf?” I said, squeezing my eyes shut in a grimace.
“Yep,” she said again. “Your soleus is muscle is so tight, that it’s pulling on the structures that wrap underneath the arch of your foot, which in turn are forcing your shin muscles to work overtime. The fascia of your posterior tibialis is being wrenched away from your shin bone…and when it detaches completely, that’s a stress fracture.”
STRESS. FRACTURE. I was horrified. But not as horrified as when she tried to stretch my poor little beef-jerky-of-a-soleus, and discovered just how short and tight the muscle had become.
HIGH HEELS = SOLEUS NEMESIS
When you use your calf muscles frequently—as distance runners, and most athletes, do—they can become very tight. And if you aren’t taking care of these muscles and their fascia, they can become chronically shortened. If you’ve spent an evening wearing high heels (talking mostly to ladies here, but hey, no judgment), then you know what this feels like. When your heel is raised above the ball of your foot, both your calf muscles are shortened. And if you spend enough time in this position—like an 8-hour work day, 5 days a week, in high heels—your calf muscles will start to adopt that shortened position as their new normal. This is why it is so important to be aware of your soleus: if you’re only stretching your gastrocnemius, you are only rehabbing one of your two calf muscles, and putting yourself at risk for injury.
So how does one stretch one’s soleus muscle? Great question. You’ve probably stretched your calves like this (at least I hope you have):
But the gastroc is the only calf muscle that crosses the back of the knee joint, so stretching your calves with your knee straight will only affect the gastroc. To “turn off” the gastroc and access your soleus, you need to bend your knee while stretching, like this:
You should feel a pull along the lower part of your leg, up from your heel, along your Achilles tendon (which connects the calf muscles to your heel). And since every muscle in your body is connected, you might even feel this stretch along the underside of your foot—your plantar fascia.
Beginning to see how taking care of the soleus can help you steer clear of injuries like plantar faciitis and Achilles tendonitis?
Here’s how to get into this soleus stretch. Start in a Downward Facing Dog position. Shift your weight onto one foot, and using the other foot to help guide the heel of the planted foot into the ground. Then, actively trying to keep that heel firmly on the ground, bend your knee. You should feel a soleus stretch. Still in this position, shift your body side-to-side, exploring any tightness in different sections of the muscle. Now try moving your body in small circles, trying to release the soleus in all planes of movement.
Spend about a minute in this stretch; then, repeat it with your knee straight to stretch the gastroc. Once you’ve stretched both calf muscles of the same leg, stand up and walk around. The stretched leg will feel like a million-billion bucks…and the non-stretched leg will feel like a cruddy penny.
Every athlete, every human, has the capability to troubleshoot his or her own body. If you have pain or tightness in your calves, shins, or bottoms of your feet, try stretching your soleus! The more we arm ourselves with knowledge of our own bodies, the better we are able to seek and destroy the dysfunctions that can cause injury. And injury-free athletes can run, jump, and compete with their whole heart and soleus.
Join over 70,000 coaches and athletes using Volt's intelligent training app. For more information, click here.
Learn more about Christye and read her other posts | @CoachChristye