I did it in front of my PT this morning, and she said “Don’t do that” and I asked why. She said it’s bad for your joints and ligaments and muscles. I said “Thanks for the anecdotal evidence”. I didn’t get much else out of her about joint cracking. I feel better after I crack my joints too, so it feels like a necessity. Since we’re all worried about our future, I don’t want to have arthritis in my neck and back in a few years.