Osgood Schlatter condition (formerly known as Osgood-Schlatter's disease) is a painful condition characterized by tiny fractures of the bony bump in the tibia, a bone in the lower leg. The bump is known as the tibial tubercle and lies just below the kneecap. It affects teenagers, especially during a growth spurt, and athletes of either sex who do sports that require a lot of running or jumping. It is a common, temporary condition that usually requires only rest before it heals itself. Follow the links below to find WebMD's coverage about Osgood Schlatter condition, what it looks like, how to treat it, and more.