A parent's guide · 10–15 years · Usually 8–12 weeks with progressive loading
Osgood–Schlatter Disease
Also called Osgood-Schlatter disease, Osgood Schlatters, tibial tuberosity apophysitis, lump below the knee in teenagers.
Painful bump just below the kneecap caused by traction on the growing shin bone.
Recover
What is happening to your child
The big thigh muscle pulls on the front of the shin through a tendon, and in a growing teenager that tendon attaches onto a growth plate that is still developing. Lots of running, jumping and kicking during a growth spurt irritates that spot, and the body lays down extra bone there, which is the bump you can feel. The bump often stays for good, the pain does not.
Does this sound like them?
- Pain and swelling below the kneecap
- A visible bump on the shin
- Pain with squatting, kneeling or running
- Symptoms ease with rest, return with sport
Why it has flared up now
- Adolescent growth spurts
- Tight quadriceps and hamstrings
- Repetitive jumping, sprinting and kicking
- Training volume above recovery capacity
For parents
What parents worry about most
Will the bump ever go away?
The bony bump usually stays, and that is normal, plenty of adults have one and never think about it. What we are working on is the pain and their ability to run, jump and kick comfortably.
Should they give up their sport for the season?
Rarely needed. Most young athletes do better modifying volume, especially jumping and sprinting, while building thigh and hip strength, than sitting out completely and returning to the same load.
Is this something they will just grow out of?
Symptoms usually settle as the growth plate matures, but that can take many months and the years in between matter to them. Strength and load work helps them keep playing during that time rather than waiting it out.
Grow
What you can do this week
- Reduce jumping, sprinting and shooting volume, keep the sessions they tolerate
- Use the 24-hour rule, if pain is worse the next morning, that session was too much
- Start daily isometric quad work, holds are usually better tolerated than deep squats
- Avoid deep kneeling and full squats while it is very sore
- Warm the knee up properly before sport rather than going in cold
When to get them seen in person
Book an in-person assessment with your GP or a physiotherapist if you notice any of these, or if you are simply worried. Our guides and programmes are education and exercise support, not a diagnosis.
- Pain and swelling that came on suddenly after a specific injury
- Inability to straighten the knee or take weight through the leg
- Locking, giving way, or a knee that swells up repeatedly
- Night pain, fever or feeling generally unwell
- Pain getting steadily worse despite reducing load for several weeks
Where to go from here
Step 1
Free
Read the parent guide
Understand what is happening to your child, what makes it worse, when assessment is appropriate, and how the three-stage framework works. Written by a physio, for parents.
Understand it
Get the free guideStep 2
£59
6-Week Recovery Framework
A condition-specific framework you follow at home: phase-by-phase structure, load and pain guidance, progression criteria, impact and sport-capacity progressions, and exercise demonstrations.
Load & Pain, Impact Tolerance
See plansStep 3
£395
12-week personalised rehab
The same three stages, built around your athlete after a 1:1 video assessment, with bi-weekly physio check-ins, changes as they progress, and return-to-sport screening.
All three stages, with support
See plansEvidence Hub
More on Osgood–Schlatter Disease
Evidence-informed articles for parents and coaches on this condition, growth-related injury and youth athletic development.
Hypermobility and Growth-Related Injuries: Key Recommendations for Parents
Bendy joints and a growth spurt are a common combination behind knee, heel and back pain in young athletes. Here is why the two interact, and what parents can do about it.
ReadWhat Is a Growth Spurt (PHV) and Why Does It Matter for My Child's Training?
Peak height velocity is the fastest point of your child's growth spurt, and it is the period when growth-related injuries cluster. Here is how to spot it and what to change in their week.
ReadGrowth Plate Fractures: A Parent's Guide to the Types and What Rehab Involves
Growth plate fractures are common in children and most heal well. Here is what the five types mean, why the classification changes the plan, and what physiotherapy actually does afterwards.
ReadWhen Bones Finish Growing: Ossification Timing in Adolescent Boys and Girls
Growth plates do not all close at once. Knowing roughly when each one hardens, and that girls run about two years ahead of boys, explains why certain injuries appear at certain ages.
ReadWhy Do Growth-Related Injuries Happen?
Growth-related injuries are not bad luck. They are the predictable result of demand outrunning capacity at a specific point in development.
ReadHow Growth Spurts Affect Strength, Speed and Sports Performance
A growth spurt temporarily scrambles coordination and can flatten performance for months - then hands back a bigger, more powerful athlete if training is handled well.
ReadOther conditions