The Most Important Muscle You’re Not Training - Rehab or Sport!
The Soleus - The Calf Muscle That Johnny Drama Doesn’t Care About…
Anatomy and Function:
Your calf complex is made up primarily of two muscles - your gastrocnemius (gastroc for short) & your soleus. The gastroc is the muscle that gets a majority of the love. It is the larger and more superficial of the two muscles. This is usually the one people are complimenting when they say someone has “nice calves”. The other, more unsung hero is the soleus. The soleus sits lower on your leg and deeper to the gastroc. Both of these muscles attach into your Achilles Tendon on the back side of your ankle.
Both of these muscles are responsible for plantar flexion or the action of pointing your toe. This action assists you with pushing off the ground. Obviously this action seems pretty important if you’re going to run, jump, change direction, or even just walking. These muscles have a BIG role to play in applying braking forces for you to handle changing direction and landings.
The gastroc can be trained with your standard standing calf raises, POGO leaps (see other blog post about the plyometric terms I like to use courtesy of Matt McInnes Watson), drop jumps and the like. And these are all great exercises to build strength, capacity, and resiliency of the gastroc and the Achilles Tendon. However, the common denominator here is that all of these exercises are done with your knee being extended or close to full extension.
Where the soleus makes its money is by the work it does when your knee is more bent or flexed. The soleus has been found to be a primary worker once the knee reaches about 20-35 degrees of knee flexion (depending on where you read). So going back to the more traditional exercises like standing calf raises, POGO leaps, and drop jumps - you won’t be in enough knee bend or depth to effectively target the soleus and will primarily feed the gastroc.
Due to the soleus’ high activity level when the knee is bent it has an even bigger role to play in sporting environments. Think of when you’re accelerating, changing direction, or jumping - what is the position of your knee? Usually these movements require you to be in a deeper knee bend to do safely and efficiently. This is why training the capacity of the soleus is so important. Your strength in and out of these positions can help speed you up or provide the necessary control for these demanding positions.
If the soleus doesn’t have the capacity to help decelerate/control these moments that force has to go somewhere. That means up the chain to your knee (ouch) and/or your hip (no thanks).
In a rehab context this is important to train the soleus for you or anyone experiencing lower extremity pain given its role in absorbing forces in these moments. Better force absorption upon ground contact could help better distribute the forces before they have to go up the chain.
So enough talk - what actions can you take to train the soleus.
Soleus Exercises:
Seated Calf Raises
Simple. Effective. Maybe one you already had in your toolkit of exercises. Some gyms come nicely equipped with a seated calf raise machine. Or you can use something like a heavy kettlebell, barbell, or SSB on your knee.
With the critical role of the soleus being to decelerate or control movements that lead us into dorsiflexion (toe/foot coming up towards the shin) I believe it is critical to make sure there focus on the lowering (eccentric) phase of this exercise.
One of my favorite ways to do this with clients is once we have done the exercise for a few sessions is to overload a single leg at a time. Select a weight that you can not raise with one leg but can slowly (read controlled) lower over 3-5 seconds. You will use both legs to raise up and lower with one leg at a time. 3 sets of 6-8 reps.
You can also cycle in quicker variations focusing on moving the weight up as quickly as you can as the soleus does need to produce a significant amount of force to push off.
Alternative - Standing Knee Bent Calf Raises
If you don’t have access to a seated calf raise this is a decent alternative. I call these “Michael Jacksons” as well. Stand near a wall and place your fingertips against it with your chest upright. Bend your knees a significant amount (> 45 degrees) but keep your heels on the ground. In this crouched position drive your knees toward the wall by raising your heels off the ground. Slow and controlled is the name of the game on these. Each rep should take about 3 seconds to complete 1 second up - 1 second hold at top - 1 second lower. Do 2-3 sets of 20 reps.
2. Soleus Isometrics
Yielding Soleus Isometric
Anyone who has worked with me - clients or other PTs know that I LOVE my isometrics. I got this one in particular from David Grey (my other PTs/coaches out there should definitely give him a follow). But you assuredly get out of this one what you put in. It can be as easy or as difficult as you make it. Lie on your back by a wall with your hips and knees at about 90 degrees of bend. Rest your feet flat on the wall. This is the starting position. Bring your butt slightly off the floor and lift your heels off of the wall by applying pressure through the ball of your foot at the base of your big toe. Squeeze your calf AS HARD AS YOU CAN. You will only get out what you put in. Hold for 30 seconds and complete 2-3 times. Progress to single leg as necessary. This 90 degree knee bend and maximal effort heel raise off the wall will challenge the soleus in its shortest position as a muscle building capacity in one of its typically weaker positions.
Overcoming Soleus Isometric
This will be done using the seated calf raise machine or a safety bar set up mentioned earlier. Your set up should have it so that your heel is able to drop below your toe putting a little stretch on your calf. Your weight selection should be heavy enough that you CANNOT move whatever apparatus you are using. You will be pushing into what essentially an immovable object as hard as you can. Hold for 5-8 seconds and rest for 45-60 seconds. Repeat 3-6 times. This will build maximal strength and capacity in the soleus’ lengthened position - the dorsiflexed position you often find yourself in when in an athletic setting.
3. Deep Plyometrics and Jumps
As mentioned earlier, Pogos, drop jumps, and other commonly used plyometrics are typically done with a more extended knee. This next exercise is more of a group of exercises or a slight shift in focus. The others still have their very important place in a program, however, occasionally adding in some some deeper knee bend jumping and plyometric work can only help you.
Some examples:
Altitude Drops with Squat Landing
One is simply landing with the knees pre bent in a deeper squat not landing straight legged and then descending into a squat. Landing with this initial deep knee bend position will target the soleus and is a really good way to drive some high velocity overload to the soleus.
Deep Knee Bend/Squatty Hops
Similar to the Altitude Drops. Repeated hops staying in that deep knee bend can be a great way to get some rebound and elastic overload into the soleus with the sid perk of burning the heck out of the quads.
Hill Sprints
10-20 yd uphill sprints. In order to scale the hill you will have to be in a deeper knee bend and therefore isolate the soleus a little bit better. No equipment required!
And there ya go! This is just scratching the surface but is a wrinkle to throw in your training/rehab to round things out! I hope this helped some of you and I’ll see ya next time! If you learned anything don’t forget to sign up for the newsletter where we go over topics like this and more!
