Chiropractics and massage therapy in conjunction. Gotta relax the muscles and put the discs back in alignment manually. Fixing one without the other will keep the problems reoccurring.
Backs don't just "go out" suddenly, from nowhere. It seems like they do, but really the problem has been building up without being noticed, then you just turn your head, move your arm or stand up and BAM you have terrible pain! The one small action only was the was the final trigger on a problem that has been building.