Shin splint causes range from the seemingly obvious to the obscure. In most cases, it's the result of overuse. A novice runner who doesn't ease into a regular workout routine is particularly vulnerable. But even seasoned runners who increase their mileage rapidly are at risk. Many experienced runners subscribe to the 10 percent rule which says you shouldn't increase your running mileage more than 10 percent from week to week. So, if for example, you have been running 30 miles per week, it would be a mistake to increase your mileage to more than 33 miles the following week. Excessive training coupled with inadequate recovery is a recipe for disaster [source: Runner's World].
A lot happens to your body when the rubber meets the road. The surface you run on plays a big part in causing shin splints. Pounding the pavement, literally, can put extra stress on your calves. The type of surface you're running on and whether it's flat, sloped or uneven can contribute to your risk of developing shin splints. The harder the surface, the more shock your body has to absorb. When it comes to the outdoors, concrete is the worst culprit followed by asphalt. Running up or downhill puts additional stress on the muscles, bone and connective tissue in your feet and legs and can also lead to injury. A dirt or wood-chip trail is much more forgiving and can reduce the risk of injury [source: Steckel].
Wearing old or worn-out shoes can also get you hurt because they don't cushion the blow adequately when your foot hits the ground. Instead, the shockwaves jolt your musculoskeletal system. Also, if you have flat feet or if you run in shoes without adequate arch supports, you're more at risk. A flat foot -- or even a normal foot without arch supports -- collapses, stretches and eventually fatigues the muscles and tendons with each step. When the muscles surrounding the tibia are stressed, the surrounding sheath can become inflamed and painful.
Shuffle over to the next section to learn more about shin splint treatments.