What is runner's knee (patellofemoral pain syndrome)?

The joint involved

The kneecap (patella) sits inside the tendon of the front thigh muscle and glides in a groove at the end of the thigh bone (femur). Together they form the patellofemoral joint. Each time you bend the knee under load, for example squatting, climbing or landing, this joint takes force several times your body weight.

In patellofemoral pain, the tissues around and under the kneecap become sensitised to that force. The joint is not worn out or torn. It is reacting to more load than it is currently conditioned for.

Why it is called runner's knee

It is one of the most common reasons runners see a doctor, but the name is misleading. It affects footballers, padel and basketball players, people doing gym classes, hikers, and many people who do not play sport at all. Teenagers, especially girls, and young adults are commonly affected.

How it usually feels

• A dull ache around, under or behind the kneecap rather than one sharp point
• Worse on stairs, especially going down, and when squatting or kneeling
• An ache after sitting for a long time with the knees bent
• Sometimes a grinding or crackling feeling without swelling
• Often both knees, though one is usually worse

Is it serious?

Patellofemoral pain is not dangerous and does not usually lead to lasting damage, but it can be stubborn. Recovery commonly takes several weeks to a few months with a structured programme. Surgery is rarely part of the treatment. Because other conditions, such as kneecap instability, cartilage injury or tendon problems, can feel similar, persistent pain is worth an examination by a knee specialist in Doha to confirm the diagnosis.