It's not her job skills -- Dr. Robert Szabo says Johnson is an excellent nurse -- but rather her incessant knuckle-cracking that makes him want to strangle her. So when his colleague Dr. Robert Boutin, a radiologist at UC Davis, asked him to collaborate on a knuckle-cracking study, Szabo jumped at the chance. What causes the crackBeyond the good and bad of knuckle-cracking, Boutin and Szabo wanted to know what exactly is going on inside a joint that's being cracked. The mythology behind knuckle-crackingSo if knuckle-cracking doesn't appear to be bad for you, how did it develop such a bad rap? He thinks he might have a clue, based on the passionate response he received when he published his own knuckle-cracking study last year.

Source: CNN August 18, 2016 11:48 UTC