If you are an avid runner, you might be familiar with a painful condition known as runner’s knee. Also known as patellofemoral pain syndrome, runner’s knee is a gen​eral term that refers to a sharp pain, swelling or discomfort behind or around the kneecap that acts up after a run.

“Runner's knee is the most common overuse injury among runners,” says Associate Professor Paul Chang Chee Cheng, Senior Consultant and Director, ​ Orthopaedic Sports Service, Department of Orthopaedic Surgery, Singapore General Hospital​ (SGH), a member of the SingHealth​ group. In Singapore, up to​ 50 per cent of runners suffer from runner's knee.

Such knee pain tends to strike runners because of the repeated stress and impact across the knee during a run, which can lead to the degeneration or damage of the cartilage beneath the knee cap.

“But runner’s knee is not merely a runner’s ailment – it can affect athletes who engage in other sports like biking and jumping too,” clarifies A/Prof Chang.

There are also other reasons which contribute to runner’s knee, such as weak thigh muscles, flat feet, bone malalignment (caused by conditions like bow legs or knock knees) as well as a direct trauma to the knee, like a fall. Tendinitis which affects the soft tissues around the knees can also cause pain after running.

You may have runner’s knee if you have:

1. ​A sharp pain behind or around the kneecap
2. A sharp pain when you bend your knee, such as when you are walking, squatting, kneeling, or running
3. A swollen knee
4. Popping or grinding sensations in the knee​​

If you have been experiencing these signs and symptoms of runner's knee, it would be wise to get your knees checked by a sports physician or an orthopaedic surgeon. “Depending on the severity of the symptoms, y​​ou may need to go through tests like an x-ray, magnetic resonance imaging (MRI) and computed tomography (CT) scan,” says A/P Chang.

Ref. T12