Osgood-Schlatters lesion occurs due to degnerative change in the region of insertion of the patella (kneecap) on the long bone of the lower leg. This condition occurs in girls and boys between the ages of ten and fifteen years. It occurs in periods of rapid growth and high levels of physical activity. Modification of activity and changes in biomechanics through the use of various devices may limit the discomfort associated with the condition. The condition is self limiting and does not normally cause problems in the long term.