How come I get shin splints on treadmill and never while I am running outside?

Anon,

Welcome to EmpowHER. Thank you for a really interesting question!!

Before I read your question, I would not have known that a person could get shin splints from running on a treadmill. I would have presumed that the surface of the treadmill belt would be soft enough to prevent such a thing (since we most ordinarily get shin splints from running on hard surfaces). But the more I read about it, the more I understood how it can happen.

First, a couple of questions. Are you wearing the same shoes both times? I want to be sure that our answer is not related to something this simple.

And do you do the same kind of stretching warmup both times? Sometimes when we're in a gym, we tend to cut the warmup short a little bit in order to get to the real work. But that stretching is crucial.

Do you tend to run faster on a treadmill? Might you be pushing yourself to do more on a treadmill than you do outdoors, increasing the pounding that your shins are taking?

My first inclination was to wonder if your stride changes when you run on a treadmill vs. running outside. Especially if you naturally have a long stride, I can see how shortening that stride for a treadmill could change the impact down the front of your legs. And when we run outside (unless you run on a track), we are running on differing inclines - straight for a bit, uphill for a bit, downhill for a bit, we turn this way and that. We go faster for a bit, and then slower for a bit. We might stop to cross the street or take a drink. We are not running in such a steady, repetitive fashion as we do on a treadmill.

Here's an article that recommends stretching and then setting the treadmill to an incline to avoid shin splints:

http://www.ehow.com/how_2300464_avoid-shin-splints-treadmil.html

Here's a runner's forum discussion on this:

http://www.runningforums.com/Shin_splints_on_the_treadmill__t12567.html

And this tip notes that a zero incline can actually make the legs mimic their downhill motion (as you know, those of us apt to get shin splints often feel much more pain running downhill):

http://www.fitsugar.com/2378062

These things actually make sense to me (and I used to be a runner but my knees took a pounding and I decided I had to stop). Do they help you at all?