My son has a painful bump below his knee. What is it?

What is going on

During growth spurts, bones lengthen faster than muscles and tendons. The thigh muscle pulls through the patellar tendon onto a growth area at the top of the shin, called the tibial tubercle. Repeated running, jumping and kicking irritate this growth area, which becomes swollen, tender and sometimes enlarged.

It is often seen in children who play football, basketball, volleyball, gymnastics or athletics, and it can affect one or both knees. Boys are often affected slightly later than girls, matching their later growth spurt.

Typical signs

Parents and children usually describe:

• A tender lump just below the kneecap
• Pain during or after running, jumping, kicking or climbing stairs
• Pain when kneeling, including during prayer
• Relief with rest, then pain again with the next training session
• No locking, no giving way and no night pain

What you can do now

Reduce the activities that hurt most for a while, rather than stopping all sport. Ice for 15 minutes after training, a cushion when kneeling, gentle stretching of the thigh muscles and simple pain relief, as advised by a pharmacist or doctor, often help. A strap just below the kneecap can ease pain during sport for some children.

When to get it checked

Book an assessment if your child is limping, the pain wakes them at night or is present at rest, the knee joint itself is swollen, they have a fever or feel unwell, the pain is in an unusual spot, or it followed a fall or a sudden pop. In Doha, Dr. Gelber examines the knee, checks growth and alignment, and decides whether an X-ray is needed.