Until recently, it was common knowledge that knuckle cracking was not only annoying but also terrible for your joints. Several new studies have upended that idea, however. Some suggest it might serve as a good indicator that a joint is well lubricated.

Commenting on a recent study in PLOS One, Greg Kawchuk, lead researcher and professor of rehabilitation medicine at the University of Alberta, said, "Although speculative, we wonder if being able to crack ones joints is a sign that the joint is actually healthy and that the inability to do so could be a sign of joint problems to come."