Is your child complaining of knee pain? If so, there is a chance it may be Osgood-Schlatter disease. According to the Mayo Clinic, a common cause of knee pain in youth is Osgood-Schlatter disease. Although the word "disease" is in the name, it is not really a disease, but rather an overuse injury. Osgood-Schlatter disease is an inflammation of the bone, cartilage, and/or tendon...