Raise your foot if you’ve ever had shin splints.
Because this is perhaps the most common issue of the lower leg in runners (except for plantar fasciitis, maybe?), I thought you'd like to know how shin splints are created. How they’re probably created, I mean. Why probably? Because shin splints is really a general term and doesn’t mean any one specific pathology of the lower leg. A shin splints diagnosis covers all the general pains experienced in the front of the lower leg.
So, understanding that not ALL shin splints will fall into the same category, this post will address where MOST shin splints come from, mechanically speaking. But before we get to the shin splints, we need to have an anatomy lesson to assess beyond how the body looks and how the body got there.
Let us consider the 90° (anatomical or neutral position) ankle angle and then let us consider how the ankle angle came to be. In order to do that, you need to pan out and consider the environment and which forces are acting on the lever system.
In both of these pictures, the ankle joint is 90°, see?
The joint position is the same, but the forces in this body are entirely different. In the first picture, the ankle position is maintained by the physical barrier created by the floor. In the second picture, the ankle position is created by the muscles down the front of the shin -- the anterior tibialis. Why? Because if these muscles weren’t contracting concentrically (actively shortening) the foot would look like this:
because of, you know, gravity and stuff.
I know you covet my sweet floors.
Now, obviously, everyone’s foot is under the effect of gravity when it is up in the air. But some people also have so much tension in the muscles of the backs of the legs, that their plantarflexing (toe pointing) force is greater than gravity. You can see if you’ve got a lot of lower leg tension by taking the Barbie Foot test here (click).
Let's say you're walking -- or trying to walk -- heel to toe. Let's also say you also have very tight calves. Instead of having to use that front-of-the-shin muscle a little (as in just enough to lift the foot against the torque created by it's weight created by gravity), you've got to use that front-of-the-shin muscle MORE than you normally would. You've got to use it enough to overcome the tension in your calves trying (and trying hard!) to point your foot. So now you've got a SUPER-STRONG front-of-the shin muscle.
Which sounds good right? Because we keep thinking that stronger and tighter is more awesome than weaker and looser. Which I get. When you read the words weaker and looser it just sounds like socks flapping around the ankles, and that isn't attractive to most people. But, I'll again say that tighter and stronger often causes problems. And in this case, the constant tension in the front-of-the-shin muscle causes this muscle to pull away from the bone. I used the term pull away because it reads nicer than rips away, which is really what it is doing. The tension in the muscle tears the connective tissue at the bone, which is, well, painful.
It is also why the shin splint braces velcro from outside toward the inside of the leg.
These braces apply medially-directed (toward the mid-line) pressure to the muscle, helping it smash back toward the bone, easing the tension on the connective tissue. Aaaaaah.
But the pain, and the torn tissue is not the root problem. The calf tension is the root problem. And the hamstring tension too. And being honest, these aren't even the root problem, as the posterior leg tension comes from our habits (shoes, sitting and resulting gait). See how it all quickly points back to The Bigger Picture?
The moral of the story? If you're a runner, walker, or just a Sally or Joe with shin splints, you need this book and the exercise program within it:
I don't care what the cover says and looks like. This book is not just about feet, but about how to help your (man or woman's) body unlearn the anatomical adaptations (your men's or women's) footwear has created.
The other moral of the story is this: We keep teaching (and learning) anatomy (i.e. muscle action and joint positions) without teaching the physics that govern them. You cannot memorize anatomy. You must be able to deduce "what a muscle does" every time, depending on what all the other muscles were doing just before you started to analyze, the position of the entire human body relative to the ground, and what the human is wearing.
Just kidding on that last part. Unless you are wearing a weight vest.
Go get this book. Seriously. Your shins (and knees, and hips, and back and...) will thank you.