Does chiropractics really heal or is it all just quackery?

Not logical. Chiro offers a strenuous massage which frequently feels very good. It cannot diagnosis anything, and offers no cure for anything. To be fair, most chiros are educated a schools of chiropractory at which place the professor tells them this stuff works. Would they doubt such an authority figure? And it is lucrative.
Two schools. Newer chiropractors see themselves as elite allied health professionals focused on real musculoskeletal medicine and reject the obvious untruths of the past. Yet a friend of mine who is a dc but works as a security guard was told on entering school that to make a living, a dc must knowingly add some health fraud. Let's wish the scientific dc's the best and be hopeful.