The shinbone is the larger of the two bones in your lower leg, running from your knee down to your ankle. If you sit down and feel the front of your lower leg, that hard ridge you can touch right under your skin is your shinbone. Its medical name is the tibia.

Your shinbone does important work: it carries most of your body weight when you stand, walk, or run. The other bone in your lower leg, the thinner fibula, sits beside it and helps with balance and muscle attachment, but the shinbone handles the heavy lifting.

Because the shinbone sits so close to the surface of your skin, with hardly any muscle or fat protecting it, banging your shin against something hard really hurts. Anyone who's walked into a coffee table corner or taken a soccer ball to the shin knows that sharp, ringing pain. The shinbone is also a common place for stress fractures in runners and athletes who train intensely.