Greetings. I'm not sure... I crack my joints because I feel pain there like my fingers hurt due to problems with fine motor skills so I crack my fingers a lot. My legs also crack a lot because I have some knee/tibia problem so they crack all the time. I don't really crack my fingers or anything for anxiety reasons. I'm not obsessed about it. If you crack your fingers (as an example) because you believe that if you don't, your bones would fall off (as an example) then that would be OCD. It depends why you do so in my opinion.