Osgood-Schlatter: Bump Below the Knee in Active Children

Reviewed by the Physiotherapy Team at Waterloo Sports Medicine Centre 

Has your child or teenager developed a painful bump just below the kneecap after playing sports? They may have Osgood-Schlatter disease, one of the most common causes of knee pain in growing children and adolescents. 

Despite its name, Osgood-Schlatter disease is not actually a disease. It is a temporary overuse injury that affects the growth plate at the top of the shinbone. With proper management and rehabilitation, most young athletes recover fully and return to the activities they enjoy. 

What Is Osgood-Schlatter Disease? 

Osgood-Schlatter disease (OSD) is an overuse injury that causes irritation of the growth plate (tibial tubercle) just below the kneecap, where the patellar tendon attaches to the shinbone. During growth spurts, the bones often grow faster than the muscles and tendons, increasing tension on this growth plate. Repetitive running, jumping, and kicking can lead to pain, inflammation, and a noticeable bony bump just below the kneecap. OSD most commonly affects children between 10 and 15 years of age, particularly those involved in sports. 

What Causes Osgood-Schlatter Disease? 

Osgood-Schlatter disease develops from repetitive stress on the patellar tendon during periods of rapid growth. 

Common contributing factors include: 

• Growth spurts 

• Running and jumping sports 

• Repetitive kicking 

• Tight quadriceps, hamstrings, or calf muscles 

• Sudden increases in training volume or intensity 

• Participating in sports year-round with limited recovery time

Sports commonly associated with Osgood-Schlatter disease include: 

• Soccer 

• Basketball 

• Volleyball 

• Track and field 

• Hockey 

• Gymnastics 

Common Symptoms 

Symptoms usually develop gradually, may affect one or both knees and may include: 

• Pain and tenderness over the bony bump just below the kneecap 

• A swollen or enlarged bump at the top of the shinbone (tibial tubercle) 

• Pain during or after running, jumping, squatting, climbing stairs, or kicking 

• Pain when kneeling or putting pressure on the bump 

• Tightness in the front or back of the thigh 

• Symptoms that improve with rest but return during activity 

  
  

How Is Osgood-Schlatter Disease Diagnosed? 

A physiotherapist or healthcare provider can often diagnose Osgood-Schlatter disease based on your child's symptoms, medical history, and a physical examination. 

X-rays are not usually necessary, but they may be recommended if another injury or condition is suspected.

How Can Physiotherapy Help? 

Physiotherapy can help reduce pain, improve flexibility and strength, and allow young athletes to safely continue participating in sports whenever appropriate. 

Your physiotherapist may recommend: 

Activity Modification 

Reducing or modifying activities that aggravate symptoms while encouraging your child to remain as active as possible within their comfort level. 

Stretching Exercises 

Improving flexibility in the quadriceps, hamstrings, calves, and hip muscles can reduce tension on the patellar tendon. 

Strengthening Exercises 

A progressive strengthening program may focus on the: 

• Quadriceps 

• Hamstrings 

• Gluteal muscles 

• Core muscles 

Improving lower limb strength can reduce stress on the knee during sports and daily activities. 

Movement Retraining 

Improving jumping, landing, running, and squatting mechanics may help reduce repetitive stress on the knee. 

Patellar Tendon Strap or Taping 

In some cases, a patellar tendon strap or taping techniques may help reduce discomfort during activity. 

Recovery and Healing Time 

Osgood-Schlatter disease is a self-limiting condition, meaning symptoms usually resolve once the growth plate matures. 

Recovery varies depending on the individual and activity level. 

• Mild cases: Symptoms may improve within a few weeks to several months with activity modification and rehabilitation. 

• More persistent cases: Symptoms may come and go during growth spurts and can last 12–24 months before resolving completely. 

  
  

As symptoms improve, the bony bump below the kneecap often remains. This is a normal result of the healing process and is usually painless once the growth plate has matured. In most cases, it does not affect knee function or participation in sports. Most young athletes can continue participating in sports as long as pain remains manageable and activities are modified as needed. 

When Should You See a Physiotherapist? 

Consider booking an assessment if your child has: 

• Knee pain during or after sports 

• A painful or enlarging bump just below the kneecap 

• Pain with running, jumping, kneeling, or climbing stairs 

• Symptoms that persist despite rest 

• Difficulty participating in sports or physical education 

Early assessment can help reduce pain, improve movement, and support a safe return to sport. 

Is your child experiencing knee pain during sports or noticing a painful bump below the kneecap? The physiotherapists at Waterloo Sports Medicine Centre can assess the cause of their symptoms and create a personalized treatment plan to help them stay active and return to sport safely.