There is no such thing as alternative medicine
What do you call alternative medicine that works? Medicine.
Chiropractors and acupuncturists are quacks. Both have done a remarkable job misrepresenting and marketing themselves so that they seem legitimate. I don't know about the USA, but over here chiropractic is taught in some universities, which should be to their eternal shame. They should know that if they let these charlatans into their campus, they will pay a price in their credibility.
There is no anatomical basis to their "subluxation" theory impinging nerves and causing illness. Take an X-ray of someone with a claimed chiropractic subluxation, and their spines may very well appear normal. On the other hand, take an X-ray of someone with REAL subluxation (an "orthopaedic" subluxation) and you may very well find them with none of the diseases chiropractors assign to such subluxations.
I completely repudiate their claims of spinal manipulation curing asthma, irritable bowel syndrome, heart disease, high blood pressure, and so on. It is unmitigated BS.