This “Ask Well” piece at the New York Times doesn’t explicitly address an asana practice, but name me someone who hasn’t had cracking and popping happen and I’ll point out to you someone who isn’t practicing asana properly. Part of the answer:
The crackling or popping sound you hear is known as crepitus. In some cases, it may be nothing more than bubbles of gas popping in your joints. It can also result from the cartilage in your knees losing their smoothness, causing bones and tissue to rub together noisily when you bend your legs.
“Crepitus is extremely common,” Dr. Stuart said. “Our joints make a lot of noise.”
If things hurt, it could be arthritis or a meniscus tear.
Merry Christmas, if that’s the case. Ugh.
Posted by Steve