Here's What Causes Runner's Knee — and How a Doctor Says to Prevent It

The pain of runner's knee is typically related to one of three main conditions, Dr. Pandya said. You can estimate which one you're experiencing based on where the pain is located, but you should see a doctor for an official diagnosis.

• Generalized irritation of the kneecap: pain around the kneecap
• Tendinitis of the patellar tendon, which connects your kneecap to your shinbone: pain below the kneecap
• Tendinitis of the IT (iliotibial) band, which runs down your outer thigh from your pelvis to your shinbone: pain on the outside of your knee, sometimes continuing up your thigh

Your pain may also come from a combination of the three, Dr. Pandya told POPSUGAR. Those conditions are typically caused by:

• Overuse: the most common cause, which can be pushing your mileage too quickly or increasing pace, hills, or intensity before your body is ready.
• Lack of flexibility: "When you're really tight, you're going to place more strain on your knee as opposed to kind of distributing that strain all over the body," Dr. Pandya explained.
• Weak core: A lack of strength in your glutes and abdominals may cause you to place more strain on your knees, Dr. Pandya said.

If you're experiencing runner's knee, first figure out when the pain is occurring. Experiencing light pain or soreness for a while after a run might be something you can manage with icing and anti-inflammatories, like ibuprofen or Advil. But if that doesn't help, or if the pain is worsening as you run, "that's a good sign that you need to take one to two weeks off and let everything rest," Dr. Pandya told POPSUGAR. Continuing to run on a potential injury, especially one that may be caused by overuse or poor form, will only exacerbate the problem. While you're resting your knees, take the time to see a doctor about your knees; they can tell you with more certainty what exactly is causing the issue and what you can do to treat and prevent it. (More on that ahead.)

You may also need new shoes, Dr. Pandya said. Experts recommend replacing running shoes every six months or 300 to 500 miles to prevent injuries, of which runner's knee is only one; you might also be at risk for shin splints and foot pain.

One of the best ways to prevent runner's knee is to avoid overuse, aka running too much. "You shouldn't increase your mileage more than 10 percent per week," Dr. Pandya told us. A similar rule of thumb applies to increasing speed or hill training. "You shouldn't introduce more than one or two new kind of workouts or types of training per week," Dr. Pandya said.

He also recommended doing at least two-to-three core and glute workouts per week to work on strengthening those key muscles. That can help to take the strain off of your knees and relieve some of the pain. If you need a place to start, we recommend this three-minute plank workout for runners and these simple glute activation exercises.

Finally, there's the stretching and flexibility aspect. If you're going to pick one area to stretch out, Dr. Pandya said, it should be your IT band. Loosening up that area on a regular basis, and especially before and after a run, can help prevent IT band tendinitis, a leading cause of runner's knee. Dr. Pandya also recommended stretching out your hamstrings, another neglected area for runners, most of whom tend to be quad-dominant.

There's a lot going on with runner's knee, but it all boils down to fairly simple prevention and treatment techniques. Dr. Pandya summed it up for us: "If runners don't overtrain, and then spend five to 10 minutes a couple times a week working on their core and on flexibility, that'll go a long way in terms of preventing runner's knee from happening."