Injury Prevention

Ask Pete: “Can I Run If My Knees Are Popping?”

A popping sensation in your knee is probably nothing to worry about. Pete answers what the likely cause is and how to treat it.

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Question:

My right knee has started “popping” when I run. If I can run without much pain, am I risking injury by training? – Hugh

Answer:

The short answer is that while diagnosing a knee injury without in-person evaluation can be tricky, most “popping” is caused by tightness in a connective tissue called the patellar retinaculum, and most runners can safely reduce pain and keep training by incorporating short sessions of self-massage. Now for the long answer…

“Aren’t you worried running will ruin your knees?” runners are sometimes asked. 

No, we’re not. We’re worried that any injury that prevents us from running will ruin the fitness we’ve earned from weeks, months, years, and even decades of training. Plus, running strengthens your knees. It doesn’t hurt them. So stick that in your couch-surfing, Netflix-binging, toasted marshmallow butterscotch pie-eating, sedentary lifestyle, oh critic of my running addiction. But I digress.

Your knees are popping, and what’s more, you’re experiencing some pain and stiffness along with the popping. First things first: Relax.

While it’s conceivable that you have a more serious injury, it’s more likely that the popping is a symptom of patella femoral pain syndrome, better known as “runner’s knee”—a catchall phrase for pain on the front part of the knee.

But first let’s make sure this isn’t one of those serious conditions:

  1. Did you hear and/or feel a popping sensation at the pain’s outset, and did you happen to be performing a twisting motion when the injury occurred? If so, you might have a meniscus tear. You’ll want your doctor to check that out.
  2. Are you age 45-or-over, and do you have significant swelling and stiffness in your knee, especially in the morning or after sitting for a while? If so, you might want to get checked for osteoarthritis. Be aware the younger people can develop osteoarthritis, too.

If you answered, “No,” to both the above questions, then you probably have runner’s knee. And chances are good that your popping is being caused by tightness in your lateral and medial patellar retinacula, two bands of fibrous tissue located on the sides of your kneecap.

Knee anatomy, artwork
Photo: Getty Images

“Your retinacula get tight and cause patellar [knee] tracking issues,” says Mike Parkinson, a physical therapist, high school track coach, and former track star for UCLA. “That’s the cause of almost all knee popping.”

When your knee isn’t tracking correctly—that is, your kneecap isn’t sliding evenly as your knee flexes and extends—the result can be pain and inflammation. Many runners immediately think, “Cartilage damage!” But it’s often due to nerve issues associated with the patellar retinaculum itself. Parkinson suggests runners should massage the retinacula to loosen the tissue and to provide temporary relief from any pain they’re experiencing.

“I like to pull the kneecap over with my fingers either medially and laterally,” says Parkinson, “and then I like to get my thumb to the side of the kneecap, actually right underneath its edge, and rub up and down on the side of that kneecap to loosen the retinaculum.”

Of course, knee pain and improper tracking has also been linked to muscle imbalance, and Parkinson advises that any long-term approach to knee pain incorporate resistance-training exercises to strengthen the glutes, hip abductors and quadriceps.

I second this suggestion. I can’t count the number of times I resolved a painful knee issue in myself or the athletes I coach by attending to the quads and glutes. Here are a few exercises you can start with:

  • Crab Walk: Begin in a supine (face up) position, on hands and heels, with your butt a few inches off the ground. Now, alternately lift a combo of opposite hand and heel to move backward. This one’s tough, so you have permission to get out of sync.
  • Monster Walk: You’ll need a resistance band. Secure the band either above your knees or around your ankles. Then, starting with your feet hip-width apart and a slight bend in your knees, alternate legs as you step forward and out (at about 45°), mimicking the movement of Boris Karloff as Frankenstein in those old horror films.
  • Side Steps: With a resistance band around your ankles, start with your feet hip-width apart, knees slightly bent. Then step sideways until you feel significant resistance. Slide your other foot over to recreate your initial stance. Repeat. Reverse direction.
  • Hip Thrust: The most effective bodyweight glute exercise ever! Lie on your back, arms extended to your sides, heels close to your glutes. Now, lift your pelvis toward the sky, creating an upward-angled bridge from shoulders to knees.
  • Step Downs: Balance one foot on the edge of a platform or step. Hold the opposite leg, knee bent, extended in front of the platform/step. Lower your hips by bending your support leg to approximately 45°. Then return to your start position. Repeat. Switch legs.

You won’t want to crab walk too far to start, but do 5-10 reps of all the other exercises. If your popping and pain don’t get better—or if they get get worse—consider a visit to a health professional.

Otherwise, “Run, Forrest, Run!”

Have a question for Pete? Shoot us a note.

Pete Magill is a running coach, world-class runner, and author. As a coach, Magill has led his masters clubs to 19 USATF National Masters Championships in cross country and road racing and has worked with athletes of all ages and abilities. He holds multiple American and world age-group records and is a 5-time USA Masters Cross Country Runner of the Year. Magill is author of Fast 5K, SpeedRunnerBuild Your Running Body, and The Born Again Runner.