Guys, I've tried some of the stretches from this article and I was wondering about the belly twist. Most times that I perform it, I get a cracking/popping noise in my lower back similar to cracking my knuckles. It never hurts(in fact it feels pretty good) but since I had back surgery last Fall I'm a little paranoid about these things. Anyways, I'd appreciate any thoughts as to whether or not this suggests that I stop using this kind of stretch. Thanks guys.
Here's the link to the article: