system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What actually are shin splints?

I have suffered shin splints or Medial Tibial Stress Syndrome for the past 5 years. I've tried everything I possible can to get rid of them, but nothing gets rid of them for good. I've had a bone scan and everything and my GP says rest is the only cure. I've got orthotics because it's my flat feet that are causing them, but I still suffer.

I've heard multiple answers to what shin splints actually from physios, GPs, Google search. I still never remember. I've heard answers like: it's the muscle tearing away from the bone and its lack of fluid which causes bubbles on the shins.

Can someone please explain like I'm five so that I can remember once and for all!
gpt
When you see a diagram of the muscles and bones in the body, it is drawn to show that the muscles connect to the bones only at the ends of the muscles.  In reality, though, the muscles are adhered directly to the bone where they lie up against it.

If you've ever cut up a raw chicken, you know that the meat (which is mostly muscle) doesn't just fall off of the bone once the skin is removed.  You have to cut it away, often scraping the meat off of the bone.  Your muscles are stuck to your bones in the same way.

Now imagine your muscles are moving and the stresses from that motion are pulling the muscle either away from the bone or along the bone.  The parts of your muscles that are stuck to the bone get torn as the muscle moves around.  This is what shin splints are.