Start with where it hurts
| Where the pain is | Most likely | Typical age |
|---|---|---|
| Bony bump below the kneecap | Osgood-Schlatter disease | 9 to 14 |
| Lower tip of the kneecap | Sinding-Larsen-Johansson syndrome | 10 to 14 |
| Vague, around or behind the kneecap | Adolescent patellofemoral pain | 12 to 18 |
| Just below the kneecap in the tendon itself | Patellar tendinopathy | 14 and up |
| Deep inside, with swelling or locking | Needs assessment, could involve cartilage or the joint surface | Any |
A rough map of knee pain in 9 to 16 year olds.
The three growth-related patterns
Osgood-Schlatter and Sinding-Larsen-Johansson are the same idea in two places: the powerful quadriceps pulls through the patellar tendon onto a growth site that has not finished turning into bone. Sprinting, jumping and kicking irritate it. Both are self-limiting as growth completes, and both respond to load management plus progressive strength work.
Adolescent patellofemoral pain is different. There is no single tender point; the pain is around the kneecap, comes on with stairs, hills, squatting and sitting for long periods, and often affects both knees. Hip and quadriceps strength, and how the knee is loaded in landing and deceleration, matter most here.
What tends to bring it on
- A jump in training, a new season, a tournament week or the start of school sport after the holidays.
- A growth spurt in the previous six months.
- Playing two or three sports across school and club with no rest day.
- Lots of running on hard surfaces or in worn-out footwear.
- Very little strength or landing work relative to the amount of running and jumping.
What to do in the first two weeks
Judge the dose by the next morning, not by how it felt during the session. Pain that has settled by the following day means the dose was about right.
Days 1 to 3
Reduce, do not stop
Cut the highest-impact volume, repeated sprinting, jumping and shooting, by about half. Keep the parts of sport that do not hurt.
Week 1
Start isometrics
Wall sits or held leg extensions, several times a week. These usually reduce pain and keep strength while the knee is irritable.
Week 2
Add slow strength
Controlled squats, split squats, step-downs and calf raises, adding a little each week rather than chasing sessions.
Weeks 3 to 6
Rebuild impact
Landing first, then hopping, then sprinting and change of direction, before returning to full match volume.
A sensible starting approach for load-related knee pain.
When to get it assessed
Not the usual picture
Swelling of the whole knee, the knee locking or catching, a feeling of giving way, pain after a specific twist or blow, night pain in one fixed spot, a limp that is not improving, or pain plus feeling generally unwell. Any of these should be seen by a clinician rather than managed as a load problem.