DOCTOR ON CALL:Osgood-Schlatter frequently occurs in those who are good at sport

I HAVE been playing a lot of sport recently, especially football, and my knees hurt. My doctor said I have Osgood-Schlatter disease.

In spite of the alarming name, this is not a serious condition, but it is painful and frustrating as it occurs most often in teenagers who play a lot of sport.

At this age, muscles and tendons may be stronger than growing bone and, with frequent strong muscle contractions in sport, the tendon pulls hard on the bony attachment causing a traction injury with pain and swelling a few centimetres below the kneecap. The powerful muscles on the front of the thigh are attached to the knee cap (patella).

The patella is then attached through a tendon to a point on the lower leg, just below the knee. If you tighten your thigh muscles, you will be able to trace this tendon (patella tendon), which feels like a band of about 1cm wide, to the attachment on the bone at a point called the tibial tubercle. If the condition has been present for some months, this may cause quite large bumps on the lower leg. While alarming, this is not serious.

Osgood-Schlatter disease is very difficult for injured players and their parents because it frequently occurs in those who are good at sport.

The best athletes, footballers and hurlers, may compete for school, club and regional teams with training almost every day. But the growing bone may not be able to cope with the excessive training load and react by painful swelling. The only appropriate treatment is to reduce the stress on the tendon attachment, which, in effect, means rest from sport.

This is doubly frustrating as the injury occurred principally because you are so keen in the first place. But you may still maintain your cardiovascular fitness by swimming and some light skills work.

If you carry on playing, you are unlikely to do any permanent damage, but the pain will continue and eventually you will have to stop. Realistically, it is very difficult to rest and most doctors let injured players choose their own level of activity.

Rupture is extremely rare and pain is usually the worst symptom. Treatments such as ice and anti-inflammatory medication are of minimal benefit and there is little a doctor can do to help.

Very occasionally, plaster of Paris is used, but this is a last resort to ensure rest.

The good news is that this pain will go away eventually and does not cause any permanent damage.

While you do have to reduce how much you do, use it to your advantage by focusing on skills and maintain your fitness in different ways.