Hello. I'm 14 I have a habit of playing with my knuckles. I move them from right to left with my fingers making my bones crack where my knuckles are. I feel that since I do this my bones are getting weaker, now I think my fingers are being affected by this act. My mom has told my Doctor for a long time since, this habit has gone for a very long time. My knuckles now have a distinctive color. Anyways when I ever do a grip I can never go longer because the front side of my elbo begins to feel ticklish inside and weak. It's weird because, I still have lots of strength.