I've been seeing it going around the interwebs...and I'm cringing for YOU!
Will strengthening my soleus solve all my shin splint issues?
I'll do knee bent calf raises; those will fix my shin splints
or this one...
I don't know, I saw a running expert say I need to do them-so I started doing them. They're strengthening my calf, I think...
Story time:
I've used knee bent calf raises in the clinic before it was a thing.
Before it was cool.
When I was just faking it till I made it as a new grad and I logic-ed my way there.
I didn't *love* the exercise then, and I don't love it now.
So is it a bad exercise?
NO!
The only *bad* exercises are the ones that aren't right for you and your body.
Then what's the big deal?
WHY THE SOLUES?
It's a muscle in the lower leg
part of the achilles tendon
plugs into your calcaneus.
It's an important player!
But that knee bent calf raise is just...awkward.
And I know from clinic experience, when you, the runner, feel awkward doing an exercise because the movement isn't natural, we don't get the results we want:
Increased strength.
Improved neuro-motor control.
Improved neural drive.
THE SOLEUS' + SHIN SPLINTS: HOW DO YOU GET SHIN SPLINTS IN THE FIRST PLACE?
"Although the characteristic signs and symptoms of MTSS are well established, there is disagreement in the literature regarding the aetiology of MTSS"
(if you want the full scoop on what MTSS is/why it happens/what it feels like, read my previous blog post HERE!)
Is it because my soleus is weak?
"It has been shown that large and long duration of traction forces associated with over-activity of the SO muscle may also result in severe strains to the distal third of the posteromedial tibia."
Translation:
Retrospective studies (meaning past studies, NOT super recent) and suggesting that possible over-activity of the SO for long periods of time could be one factor that leads to MTSS.
(but because these are retrospective,"one can therefore not conclude as to the cause or effect of increased TA or SO activity on the development of MTSS.")
But back up: HOW are we measuring this?
Through EMG studies.
EMG =Electromyography
These tests measures the muscle's response -the electrical activity of the muscle in response to a nerve's talking to that muscle.
Do EMG tests directly measure muscle strength?
Short answer: NO
Long answer: they measure muscle activation during both isometric and dynamic actions.
EMG studies provide "valuable information about the neural control of movement, it does not provide direct information about muscle force…." (think muscle strength)
(if you're really getting into the nitty gritty: you'll appreciate this quote: "Inferring muscle force from EMG signal amplitude is even more problematic during dynamic actions compared to isometric actions")
To get to the bottom of this, we need CURRENT studies.
Hence, this one.
RESEARCH QUOTES (tap me to drop down list):
" The results of our study showed that participants who developed MTSS had a significantly higher SO (soleus) peak EMG RMS during the absorption and propulsion phase of running.
[Runners at risk for MTSS include those with:]
The body mass and BMI were larger
previous vigorous physical activity was less
and dynamic arch index during running was lower in those who developed MTSS comparison to the participants who did not develop MTSS.
a previous history of MTSS and the use of foot orthoses
SO peak EMG amplitude was higher in people who developed MTSS than those who did not develop MTSS.
This is in line with studies that reported an increased strain by a more active SO muscle on the tibia as a possible risk factor of MTSS.
The SO is attached to the medial calcaneus, and large and longer duration of traction forces associated with over-activity of the SO during supination in the propulsive period after over-pronation of the calcaneus upon landing may result in severe strains to the distal third of the posteromedial tibia.
If, without proper recovery, this is repeated over and over again during running it may ultimately lead to MTSS.
The high dynamic foot pronation in MTSS participants during running may be related to a modified alignment of the rear-foot bones along with less stable foot articulations and an increase of the tibial internal rotation during the stance phase. In turn, altered rear-foot bone configuration changes the line of pull for the SO muscle, requiring a higher activity of SO muscle to produce the same torque.
Considering that foot pronation increases with the fatigue of foot intrinsic muscles, foot and arch exercises can improve the rigidity of the foot arch that helps to better control the foot pronation and tibial internal rotation, and therefore be useful in preventing and/or treating of MTSS."
Although this quote may seem scary, DON'T forget the whole picture: "The results of this study support that although peak soleus EMG is a predictor of the incidence of MTSS, its contribution is limited in comparison to the predictive power of BMI, dynamic foot index, previous history of MTSS and level of PA. Thus, screening for the latter parameters, without considering the soleus peak EMG, provides an easy and quick screening tool to predict the risk of MTSS."
TRANSLATION:
Runners with MTSS have higher soleus activity when measured with an EMG.
These moments of higher/greater activity were during 2 specific moments of a stride:
absorption and propulsion
OR
When your forward heel/foot hits the ground AND when that same leg now has pointed toes as you take your next stride forward.
WHY YOU GET SHIN SPLINTS*
What *might* be happening is because your soleus is too active, it's creating too much strain (or effort) and essentially stressing out the back and bottom portion of your shin bone.
These particular researchers are suggesting that pain and injury begin to happen when that stress builds and builds and builds and you don't have the appropriate recovery time.
But, lets say you did have a rest day every other day.
That's not realistic for training
Rest days, while healthy and necessary! Should not be misused as bandaids for underlying issues.
Which leads us to…
WHY IS YOUR SOLEUS TOO ACTIVE?
Why is it trying to do all the work and stressing out your shin bone?
These researchers are suggesting poor mechanics in the back of the foot and the tibia itself. Also, flat feet.
Because of all these combined,"foot pronation increases with the fatigue of foot intrinsic muscles".
Their solution:
"foot and arch exercises can improve the rigidity of the foot arch that helps to better control the foot pronation and tibial internal rotation, and therefore be useful in preventing and/or treating of MTSS."
They're not wrong.
But they're not completely right.
I've tried to start runners with shin splints with the most chill, running specific feet exercises I know of to begin working on that foot fatigue.
(These exercises are my Stronger Feet Exercises).
And they bomb.
Every single time.
A runner who is in pain, currently struggling with shin splints, is NOT ready for foot exercises that engage muscles around the shin bone.
HOWEVER: those exact type of exercises are the ones can PREVENT shin splints! (I've found other research to support this; listed in previous shin splint blogs).
So you do feet exercises when you don't have shin splints; but don't do them when you do have MTSS (at least not ones that cause more pain).
BUT HOW DOES MY SOLEUS FIT IN?
The volume of the soleus is still turned up waaaay too high!
So we need to do exercises to turn it down.
Re-introduce it to its teammates
And get all the muscle teammates working together.
If you do knee bent calf raises: you are specifically biasing the soleus muscle to work harder.
But it's already working!
In fact, it might be working TOO MUCH!
So if you're in pain right now because of shin splints, I DON'T suggest doing knee bent calf raises!
We don't know if the soleus muscle is weak or strong.
We just know the volume, the level of activation, is too dang high.
HOW DO YOU KNOE IF YOUR SOLUES IS"too activated"?
You don't know for sure without an EMG study.
And physicians typically don’t hand those out like candy.
They're expensive and take time.
So don't feel you need one!
If I was seeing you in a the clinic or in a one-on-one shin splint session, we could already operate under the assumption that the soleus needs break.
Working together, we would do some testing and let your body do the talking, tell us what it needs, and let it lead the way.
Because pieces of information like from this research article are very helpful!
But, at the end of the day, we still have to paint a complete picture with your body is telling us.
Looking for where WHAT's NEXT?
Stick around for exercises next week!
Until then,
Dare to Train Differently,
Marie Whitt, PT, DPT //@dr.whitt.fit
P.S. Want to start ditching SHIN SPLINTS NOW? Make a one-on-one appointment with me! Not sure if it's a good fit? Email me and let's chat!
References:
Shin Splint Article:
DOI: 10.1080/02640414.2020.1785186
EMG JOSPT Article: