I've been a bonecracker for a number of years now (I'm 24), doing fingers,
toes, wrists, neck, whatever. I also practice cracking my back (usually
before and after sleeping, and on and off during the day). Sometimes it
produces just a slight pop, but sometimes it sounds like a timber snapping
(without pain... just the really intense relief sensation). I've done what
little research I could on the subject, and have found that it is not the
same phenomenon as finger-cracking (apparently backbone cracking is
ligaments snapping over bones, yes?), and am wondering what kinds of
physiological effects this practice might curse me with. Though it feels
good and makes me comfy, I've got these nasty visions of doing it sometime
and becoming paralyzed... =P