Runner’s knee is the most common injury for runners—so much so that runner is part of its name.

But it’s not the only cause of knee pain for runners, so it’s good to brush up on the specific symptoms of runner’s knee.

When the smooth motion of the patella along the femoral groove is disrupted, runner's knee is the result. Read: What You Need to Know About Runner’s Knee


What causes runner’s knee?

The patella, or kneecap, is fixed in place by tendons, which help it stay in place and glide along the end of the femur (thigh bone), so you can bend your knee. It slides along a notch in the bone called the trochlear or femoral groove.

See Soft Tissue of the Knee Joint

When the smooth motion or contact of the patella in the groove is disrupted, it causes patellofemoral pain syndrome, also known as runner’s knee.

Signs of runner’s knee

Although it’s common among runners, athletes of all kinds can be affected by runner’s knee, particularly those who play sports that involve repetitive use of the knee like soccer or basketball.


Signs of runner’s knee include:

  • Pain on the sides or front of the kneecap
  • Grinding in the knee (crepitus) or stiffness, especially after periods of rest
  • Increased pain or knee popping with movement, particularly when extra stress is put on the knee from climbing stairs or squatting

For a complete list of symptoms, see Symptoms of Runner’s Knee

Other conditions that can resemble runner’s knee

Unfortunately, several injuries can cause knee pain, so it’s not always easy to tell what’s causing it. Some of the other knee conditions with symptoms similar to runner’s knee include:

To determine an exact cause of knee pain, your doctor will use your patient history, a physical exam, and possibly imaging.

See Diagnosing Runner’s Knee

If you have knee pain that persists despite RICE and other self-care treatments, see your doctor so your injury can be diagnosed and treated.

See Treating Acute Sports and Exercise Injuries in the First 24 to 72 Hours

Learn more:

Treatment of Runner’s Knee

Jumper’s Knee vs. Runner’s Knee