Q: When I bend my knees in yoga poses I hear a crackling sound. I also hear this sound when I am climbing stairs. It doesn’t hurt but the noise seems pretty loud and I am embarrassed others can hear it. What causes this sound?
A: What you are describing is called crepitus and it is a common problem in the knee. Although there are many reasons a knee might make sounds, the fact that you have said this does not cause you pain reduces the likelihood that this is a serious problem, but you still might want to get it checked out by your doctor. He or she can rule out more serious problems and also recommend treatment that can lesson this problem.
One reason that knees make a sound can be from a condition known as chondromalacia patella. Your patella is your knee cap and this bone is embedded in the tendon of your quadriceps muscle so that your knee joint can move more freely without binding. The patella is lined with cartilage which can be damaged and become rough, thus grating against the front of the knee joint and making this noise.
The condition is more common in women and can be brought on by overuse of the knee. Certain sports can also make it more likely to develop this problem. Some people are prone to this condition is they have an alignment problem in the knee that causes the patella to rub on the lower part of the femur bone instead of gliding across it. Muscular imbalance in the muscles that stabilize the knee can bring on this issue. In addition, injury to the knee can also make knee crepitus more likely.
In your yoga it is important that you pay attention to the alignment of you knee in your poses. Make sure that you are keeping your knee in a bend no greater than 90 degrees in weight bearing poses. This will mean that your knee and ankle line up so that your shin is a perpendicular line to the floor. You should also make sure to watch out for poses that bend your knee strongly when not weight bearing such as the lotus pose or king of pigeon where the knee is folded. These can add a twisting motion to the knee and often result in worsening knee issues.
If you feel discomfort in your knee in any pose then come out of the position. In addition to your yoga, you may want to do exercises that strengthen the muscles that support you knee. Strengthening the quadriceps, especially the vastus medialis (near the inside of your lower leg) will help your kneecap track more properly. You will also want to strengthen your hamstrings and your calf muscles. With a strongly supported knee you may find your noisy knees become quieter.
As far as people around you hearing you knee, well you may not be able to become a ninja right now, but don’t worry. Knee noise is common so they probably thought it was their knees.