Osgood-Schlatter disease can cause a painful lump below the kneecap in children and adolescents experiencing growth spurts during puberty.
Osgood-Schlatter disease occurs most often in children who participate in sports that involve running, jumping and swift changes of direction — such as soccer, basketball, figure skating and ballet.
While Osgood-Schlatter disease is more common in boys, the gender gap is narrowing as more girls become involved with sports.
Age ranges differ by sex because girls experience puberty earlier than do boys. Osgood-Schlatter disease typically occurs in boys ages 13 to 14 and girls ages 11 to 12. The condition usually resolves on its own, once the child's bones stop growing.