Osgood-Schlatter disease is a common cause of knee pain in growing adolescents. It's a condition characterized by inflammation of the area just below the knee where the tendon from the kneecap (patellar tendon) attaches to the shinbone (tibia). This condition occurs most often in children who participate in sports that involve running, jumping, and swift changes in direction—such as soccer, basketball, figure skating, and gymnastics.

The main symptoms include:

• Pain and tenderness at the tibial tuberosity, the bump just below the knee.

• Swelling at the tibial tuberosity.

• Tightness of the surrounding muscles, particularly the quadriceps muscle at the front of the thigh.

The cause of Osgood-Schlatter disease is thought to be repeated tension on the growth plate at the top of the tibia. During adolescence, bones, muscles, tendons, and other structures are rapidly growing, and physical activity can place additional stress on these areas. The growth plate at the tibial tuberosity is particularly susceptible to injury during the growth spurts of puberty.

Treatment generally focuses on reducing pain and swelling. This usually includes rest, ice, and over-the-counter pain relievers. Stretching and strengthening exercises for the leg muscles can also help reduce symptoms and prevent recurrence. Most cases of Osgood-Schlatter disease will improve over time, and symptoms tend to go away once the child stops growing, although the bump can remain.