The origin of chiropractic medicine comes from the belief that all diseases are caused by spinal mis-alignments. Yes, it it hokey. Heck, they call the whole thing 'chiropractic', when the word is obviously an adjective. It's because chiropractors can't say chiropraccy. Invented by Daniel David (D. D.) Palmer in 1895 when he cured someone's deafness by realigning a vertebra. He also believed in magnetic healing, phrenology, vitalism, Mesmerism, and spiritualism.
I have the sinking feeling that most chiropractic doctors are those that couldn't get into standard medical schools, but didn't let that stop them from trying to help people.
On the other hand, the quack practice of chiropractic has been around for so long, I'm sure they've actually have gotten pretty good at reducing back pain through trial and error.
It's interesting to note that the only reason normal doctors aren't up in arms against this pseudoscience-based health care practice is because of legal action against the American Medical Association for unreasonable restraint of trade.
Don't assail me with anecdotes about how chiropractic cured your back pain. I'm just pointing out that it has no rational, scientific basis. I think if enough people moved enough spines around randomly, while still undergoing conventional therapies, at least some of their back pain will stop.
Remember, if alternative medicine actually worked, it would be called conventional medicine.