Tweetmy chiropractor informed me that it is ok that u crack ure back as long as u dont do it often. what ull end up doing is loosing ure muscles and tendens or whatever is ther that holds up ure next and ull be more subseptible to headaches and and neck aches especially if ure at the comp for many hours. chiropractors adjust ure back and the crackin is just a gas being released from the joints