Just a thought...you might want to look into getting a Myofascial Release done as well. If your back is out of wack...odds are it is your muscles pulling it that way. The Chiro will re-allign everything but the muscles will eventually start pulling again. With a Myofascial Release they basically feel for any trouble spots (small bumps in your muscles) and push on them basically as hard as they can until the bump goes away.
My Sister does it for family in her free time (is an OT...so she does have medically schooling to back it up) and everyone that she has done it to swears by it. Just be warned...depending on how bad your muscles are it will hurt like hell if they do it right. My sister brings tears to her Husbands eyes when she does it for him (he is a tractor mechanic...so he is hard on his back)...and he is a tough guy.
Just my .02
Edit...
http://en.wikipedia.org/wiki/Myofascial_Release