Runner’s knee is the common term used to describe any one of several conditions that cause pain around the kneecap (patella). It can be caused by running or any activity that repeatedly stresses the knee joint.

Conditions that can cause Runner’s knee include anterior knee pain syndrome, patellofemoral malalignment, chondromalacia patella, and iliotibial band syndrome.

According to the Harvard Medical School, runner’s knee is more common in women than in men, particularly in women of middle age. People who are overweight are especially prone to the disorder.

The hallmark of runner’s knee is a dull, aching pain around or behind the kneecap, or patella, especially where it meets the lower part of the thighbone or femur.

You may feel pain when:

  • walking
  • climbing or descending stairs
  • squatting
  • kneeling
  • running
  • sitting down or standing up
  • sitting for a long time with the knee bent

Other symptoms include swelling and popping or grinding in the knee.

In the case of iliotibial band syndrome, the pain is most acute on the outside of the knee. This is where the iliotibial band, which runs from the hip to the lower leg, connects to the tibia, or the thicker, inner bone of the lower leg.

The pain of runner’s knee may be caused by irritation of the soft tissues or lining of the knee, worn or torn cartilage, or strained tendons. Any of the following can also contribute to runner’s knee:

  • overuse
  • trauma to the kneecap
  • misalignment of the kneecap
  • complete or partial dislocation of the kneecap
  • flat feet
  • weak or tight thigh muscles
  • inadequate stretching before exercise
  • arthritis
  • a fractured kneecap
  • plica syndrome or synovial plica syndrome, in which the lining of the joint becomes thickened and inflamed

In some cases, pain begins in the back or hip and is transmitted to the knee. This is known as “referred pain.”

To confirm a diagnosis of runner’s knee, your doctor will obtain a complete history and conduct a thorough physical examination that may include a blood test, X-rays, an MRI scan, or a CT scan.

Your doctor will tailor your treatment to the underlying cause, but in most cases, runner’s knee can be successfully treated without surgery. Most often, the first step in treatment is to practice RICE:

  • Rest: Avoid repetitive stress on the knee.
  • Ice: To reduce pain and swelling, apply an ice pack or a package of frozen peas to the knee for up to 30 minutes at a time and avoid any heat to the knee.
  • Compression: Wrap your knee with an elastic bandage or sleeve to restrict swelling but not too tightly as to cause swelling below the knee.
  • Elevation: Place a pillow under your knee when sitting or lying down to prevent further swelling. When there is significant swelling, keep the foot elevated above the knee and the knee above the level of the heart.

If you need additional pain relief, you can take certain over-the-counter nonsteroidal anti-inflammatory medications (NSAIDs), such as aspirin, ibuprofen, and naproxen. Acetaminophen, the active ingredient found in Tylenol, can also help. You may want to talk to your doctor before taking these medicines, especially if you have other health conditions or take other prescription medications.

Once the pain and swelling has subsided, your doctor may recommend specific exercises or physical therapy to restore your knee’s full strength and range of motion. They may tape your knee or give you a brace to provide extra support and pain relief. You may also need to wear shoe inserts known as orthotics.

Surgery may be recommended if your cartilage is damaged or if your kneecap needs to be realigned.

The American Academy of Orthopaedic Surgeons recommends the following steps to prevent runner’s knee:

  • Stay in shape. Make sure your overall health and conditioning are good. If you’re overweight, speak with your doctor about creating a weight loss plan.
  • Stretch. Do a five-minute warmup followed by stretching exercises before you run or perform any activity that stresses the knee. Your doctor can show you exercises to increase your knee’s flexibility and to prevent irritation.
  • Gradually increase training. Never abruptly increase the intensity of your workout. Instead, make changes incrementally.
  • Use proper running shoes. Buy quality shoes with good shock absorption, and make sure they fit properly and comfortably. Don’t run in shoes that are too worn. Wear orthotics if you have flat feet.
  • Use proper running form. Keep a tight core to prevent yourself from leaning too far forward or backward, and keep your knees bent. Try to run on a soft, smooth surface. Avoid running on concrete. Walk or run in a zigzag pattern when going down a steep incline.