Osgood-Schlatter disease can cause a painful lump below the kneecap in children experiencing growth spurts during puberty. Osgood-Schlatter disease occurs most often in children (9-15) who participate in sports that involve running, jumping, and swift changes of direction — such as soccer, basketball, gymnastics, and ballet. The cause of Osgood Schlatter is inflammation where the patellar tendon inserts at the tibial tuberosity. Osgood-Schlatter disease affects boys and girls the same. It is a very common injury affecting as many as one in five adolescent athletes. The pain associated w/ Osgood Schlatter should clear up when they stop growing and the tendon becomes stronger. A Note from the Doctor: We get great results treating Osgood Schlatter’s by utilizing myotherapy, stretching, and rehabilitative exercises in a limited number of visits. Usually, there is a significant decrease in pain after just one treatment and there does not need to be any time off from activity.