Find one who meets your needs. The guy I was seeing would literally make up stuff to get me to come back for regular visits that I didn't really feel I needed. My "diagnoses" would some how miraculously fit what my insurance would allow. Hmmmm.
Personally I've found the best results for my needs from a friend who is a massage therapist. But I dont' generally have back problems per se so it is appropriate. Just like any doctor, if you dont' feel confident in what they are saying, then get a second opinion or evaluate if there really is a problem.