Why Do My Knees Pop And Crack At The Gym?

By Ann Wendel

Knee pain and "noisy" knees are two common reasons that patients often go see a physical therapist. Popping or cracking, and in some cases pain while or after performing knee-dominant movements like split squats, leave them wondering if they should be concerned. The answer, as with so many other things in life, is that it depends.

The technical term for popping is crepitus, and there are a number of reasons that the knees may pop.

Sometimes the popping and cracking is not cause for concern. The knees often pop when bending and straightening, especially during weight bearing activities such as stairs or squats. The popping is usually not painful, and is caused by bursting nitrogen bubbles in the synovial fluid when force is applied to the joint. The technical term for this is cavitation, and it is what happens when you pop your knuckles.

Image source: http://www.mdguidelines.com/patella-chondromalaciaIn other instances, the popping noise can come from the joint. The cartilage on the ends of the femur, the tibia, and/or the patella (knee cap) can wear down, and this degeneration of the cartilage causes rough spots which may pop or crack with movement. Many times this isn’t painful; but, sometimes it is. With advanced osteoarthritis, many patients complain of pain, as they have lost the cushioning of cartilage and often feel bone rubbing on bone.

When the cartilage on the undersurface of the patella (knee cap) degenerates, it is referred to as chondromalacia patella. This can be the source of popping noises as you bend and straighten the knee, since the patella is rough and doesn’t glide in its track.

In some people it is very loud but not painful, and in others it only makes a little bit of noise, but is painful. Pain may not occur every day.

Most cases of chondromalacia develop over time; but, some people are born with natural anatomic variations that make them more prone to developing it. In some cases, the issue can be brought on by a trauma to the knee, such as a fall on the patella, where the cartilage is bruised or chipped.

Another possible cause of popping in the knee is a tear in the meniscus, the cartilage that cushions the joint. The tear can happen as a result of a sudden twist, or it can happen because of degeneration of the cartilage over time.

Noisy Knees GGS Pic 2Patients often complain of "locking" in the knee with a meniscus tear, and sometimes there is associated swelling. Pain is often felt at the joint line, between the femur and tibia, in contrast to the pain felt under the kneecap in chondromalacia.

It’s impossible to tell what is truly causing a person's knee symptoms without an examination. If you have popping and cracking, but you don't have an injury or swelling and don't experience locking of the knee, my best recommendation is to see a physical therapist who can evaluate your knee and watch you perform some movements, like a squat, a split squat, and a step up. A physical therapist an make recommendations based on their observations, in order to keep you doing the things you love to do.

Treatment may include mobility exercises, specific strengthening for weak muscles around the hip, and manual therapy. We will work with you to develop a plan to reach your goals. You can locate a physical therapist via the American Physical Therapist Association website.

Note from GGS: We strongly recommend including injury prevention strategies in your training program to address mobility, stability, and overall movement.

Want to learn how to get the results you've always wanted — without extreme diet or exercise?

Sign up for this FREE 5-Day course and you'll learn:

  • How to set yourself up for success (not failure) from the beginning
  • Why meal plans don't work (and what to do instead)
  • Why more exercise isn't better (and what to do instead)
  • How to overcome two major roadblocks concerning your hunger and cravings
  • The "secret sauce" for long-lasting, life-changing results — even when you're busy, injured, or unmotivated
Get started today

Top 5 Secrets to Get Better Results in Less Time

Women are tired of spending hours in the gym without seeing the results they want. Fortunately, no matter your goal, we can help. Strength gain, muscle gain, fat loss, more energy—we've got you (and your goals) covered.

This free course includes videos, downloadable tools & resources, and podcast version so you can learn on the go.

About the author:  Ann Wendel

Ann Wendel is an internationally-recognized women's health Physical Therapist (PT), a Certified Athletic Trainer (ATC), and a Certified Myofascial Trigger Point Therapist (CMTPT). In addition to owning and operating Prana Physical Therapy in Alexandria, VA, Ann writes, travels, speaks, and consults with other physical therapists and business owners. You can connect with Ann on Facebook and Twitter.

More Resources

envelope-oclosechevron-upchevron-downbookmark-otwitterfacebookchainbars linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram