By: Nuala Genyk, MScPT, HAAD Does your teenager have knee pain? It could be Osgood-Sclatter disease; a painful knee condition that typically affects growing children. It is an inflammation of the patellar tendon and growth plate just below the knee at the tibial tuberosity. It is characterized by pain at the front of the knee that is worse with activity and better with rest. Some adolescents may also have a painful bump where the patellar tendon attaches to the tibial tuberos