Snap Crackle and Pop

While warming up, do you ever hear a “popping” noise in your joints (knees, shoulder, wrists)?  What does this sound mean?  Is it okay to continue working out?  Let’s explore this together.

“Popping” and “cracking” of the joints is normal and, in general, does not correlate to anything that is worrisome.  Physical Therapists never chase noise unless it is accompanied by pain, swelling and/or joint locking.

The exact reason for popping in the joints is not well understood.  One theory is that nitrogen gas bubbles escape the joint when it is being moved or manipulated, such as when you crack your knuckles.  When the joint reaches a certain range of motion, it allows air to escape and you hear the noise.  Another theory is that these sounds are caused by roughened joint surfaces rubbing against each other.  It is normal for the surfaces of our joints to get rough, and our bodies generally accommodate this over time.  Usually, the popping decreases as we continue to move because movement causes the synovial fluid in our joints to flow, providing lubrication.  If it does not go away once you are warmed up, often changing your position slightly can decrease the amount of friction between the joint surfaces.  For example, if you near popping in your knees or ankles when doing Footwork on the Reformer, try slightly internally or externally rotating at the hips to change your alignment.  Ideally, we want the kneecap over the second and third toes, but every body is different; sometimes all it takes is a slight adjustment to decrease or stop the sound.

This popping sound might also be caused by a tendon snapping over a bony prominence; for example, the biceps tendon on the bicipital groove of the humerus (upper arm bone) as we internally or externally rotate the arm.  In this case, warming up and/or stretching generally decreases the noise. 

Whatever the cause, these sounds alone do not signify pathologies, nor do they lead to future problems.  So as long as it’s just noise without any pain, swelling or joint locking, you can keep going!