I am often asked my opinion of chiropractic care. My usual answer (based on evidence) is that it can be somewhat helpful in the treatment of low back pain. That's it. Any further claims are complete and utter bullshit. Many chiropractors practice ethically, and recognize the correct scope of their abilities...many do not.
Adapted from RationalWiki
Chiropractic is the theory and practice of correction of "vertebral subluxation processes" to treat and cure disease. It was developed in the late 19th century, just before the development of modern medical education in the United States.
Chiropractors subscribe to the theory of "vertebral subluxation". This differs from the medical definition considerably. An orthopaedic (real) subluxation is a painful partial dislocation of a vertebral body. A "chiropractic subluxation" is an asymptomatic misalignment or a "vertebral subluxation complex" thought to be a cause of disease. The mechanism posited is usually the blocking of nerve impulses from spinal roots, or some such nonsense. Such a subluxation has never been proven to exist.
Lest you think that this unproved hypothesis has died away, in July 1996, the Association of Chiropractic Colleges issued a consensus statement that:
Chiropractic is concerned with the preservation and restoration of health, and focuses particular attention on the subluxation. A subluxation is a complex of functional and/or pathological articular changes that compromise neural integrity and may influence organ system function and general health.
This hypothesis has never been tested, and ignores significant anatomical reality, such as the fact that much of the nervous system does not pass through "subluxations" in any way. This especially applies to the autonomic nervous system that "influences organ system function".
According to the American Chiropractic Association:
The ACA Master Plan, ratified by the House of Delegates in June 1964 (Amended June 1979, June 1989, July 1994 and September 2000), and will govern future policies of ACA as quoted:
"With regard to the core chiropractic principle, which holds that the relationship between structure and function in the human body is a significant health factor and that such relationships between the spinal column and the nervous system are highly significant because the normal transmission and expression of nerve energy are essential to the restoration and maintenance of health.
That's basically a re-statement of subluxation theory without the "s" word. It's also patent bullshit.
So the chiropractors haven't given up the absurd theory behind their "profession"---but does it work despite the poor theory? After all, outcomes are what count.
For back pain, there is evidence that chiropractic therapy may be as effective back exercises plus anti-inflammatory medications. Chiropractic has also been found to be slightly more effective than simply handing a patient a book about back care. In some studies, chiropractic did cost more overall. Specifically, a study comparing outcomes of acute low back pain treated by orthopedic surgeons, primary care physicians (PCP), and chiropractors found similar outcomes, but less cost from PCPs.
While 50-60% of patients who seek chiropractic care do so for back or neck pain, a significant number are treated for other problems. There is no evidence to support the use of chiropractic outside the realm of minor musculoskeletal complaints. Chiropractors who make any claims beyond low back pain are either dishonest, ignorant, or both. There is some evidence that (rarely) chiropractic care can cause stroke, carotid artery dissection, and other life-threatening problems.
Chiropractic may have a place in the treatment of low back pain---or it may not. Chiropractors are basically glorified massage therapists---except many massage therapists have better training, and know the limits of their profession. Chiropractors who discourage real medical care, vaccinations, and medications, or sell herbs and other potions out of their offices should be ashamed of themselves.
But of course, they have no shame.