Painful bump below kneecap in youth
Also Known As: Osgood-Schlatter disease, tibial apophysitis, knee growth plate pain, patellar tendon traction injury
What It Feels Like
A tender, visible bump just below the kneecap on the upper shin (tibial tuberosity)
Pain that worsens with running, jumping, squatting, or kneeling
Tenderness with direct pressure on the bump — a classic finding on exam
Common in ages 10–15, often during or after a growth spurt, more prevalent in boys
Why It Happens
The patellar tendon connects the quadriceps to the tibial tuberosity — a growth plate at the top of the shin. During growth spurts, repeated quadriceps contractions pull forcefully on this soft growth plate, causing irritation, inflammation, and sometimes new bone formation that creates the characteristic bump.
Common Causes of a Painful Bump Below the Kneecap in Youth
🔹 Osgood-Schlatter Disease (Tibial Apophysitis)
The most common cause. The patellar tendon attaches to the tibial tuberosity growth plate. During growth spurts, high quadriceps tension pulls repeatedly on this attachment, causing inflammation and a bony prominence.
🔹 Rapid Growth Spurt
When bone grows faster than the surrounding tendon can adapt, traction stress at the apophysis increases significantly — especially in athletes doing repetitive jumping, sprinting, or squatting movements.
🔹 High Sport Volume
Multi-sport athletes or those in single-sport-intensive seasons (basketball, soccer, volleyball, track) with high jump and sprint loads are at greatest risk.
🔹 Tight Quadriceps
During rapid growth, the quadriceps muscles become relatively tight as the femur lengthens. This increases patellar tendon tension and traction force at the tuberosity.
Did You Know?
Osgood-Schlatter is not a disease — it's a traction apophysitis. The bony bump that develops at the tibial tuberosity can become permanent even after pain resolves. That bump is completely harmless, but it's why some adults still have visible tibial prominences from a teenage case of Osgood-Schlatter they never knew they had.
How Zenith Can Help
At Zenith, Mariel Hammond and Jenn Randall specialize in youth athletes and understand how to manage growth-related injuries without simply telling young athletes to stop playing. We help modify training load, build quad and hip strength, improve mechanics, and guide a graduated return to full sport participation with minimal time on the sideline.
Next Steps
If the bump is tender to the touch and gets worse with sport, it's time for an evaluation. Osgood-Schlatter is very manageable with the right approach — and the sooner it's addressed, the less sport time gets lost.
Youth athletes in Eugene soccer, basketball, and track programs are especially vulnerable during spring growth spurts when training volume is high. If your athlete starts limping mid-practice or kneeling during warmup causes a yelp, don't push through it — get it evaluated early to avoid a longer forced rest later.