Vertebral Subluxation - Critiques

Critiques

Edzard Ernst has stated that the "core concepts of chiropractic, subluxation and spinal manipulation, are not based on sound science."

An area of debate among chiropractors is whether "vertebral subluxation" is a metaphysical concept (as posited in B. J. Palmer's philosophy of chiropractic) or a real phenomenon.

In an article on vertebral subluxation, the chiropractic authors wrote:

"Subluxation syndrome is a legitimate, potentially testable, theoretical construct for which there is little experimental evidence. Acceptable as hypothesis, the widespread assertion of the clinical meaningfulness of this notion brings ridicule from the scientific and health care communities and confusion within the chiropractic profession. We believe that an evidence-orientation among chiropractors requires that we distinguish between subluxation dogma vs. subluxation as the potential focus of clinical research. We lament efforts to generate unity within the profession through consensus statements concerning subluxation dogma, and believe that cultural authority will continue to elude us so long as we assert dogma as though it were validated clinical theory."

Since its inception, the concept of vertebral subluxation has been a source of definitional debate. Tedd Koren, DC offers this explanation as a possible cause of the confusion:

The vertebral subluxation cannot be precisely defined because it is an abstraction, an intellectual construct used by chiropractors, chiropractic researchers, educators and others to explain the success of the chiropractic adjustment.

This is not a unique state of affairs, abstract entities populate many branches of science...

Subluxations, genes, gravity, the ego and life are all heuristic devices, "useful fictions" that are used to explain phenomenon that are far larger than our understanding. We use them as long as they work for us and discard or limit their application when they become unwieldy or unable to account for new observations...

Critics of chiropractic have incorrectly assumed that chiropractic is based on the theory or principle that vertebral subluxations cause "pinched" nerves that cause disease. They have it backwards. Chiropractic is based on the success of the spinal adjustment. The theory attempting to explain the success of the adjustment (nerve impingement, disease, subluxations) followed its clinical discovery.

Examples of such erroneous criticisms based on this straw man argument abound in the medical literature. Some examples: "The teachers, research workers and practitioners of medicine reject the so-called principle on which chiropractic is based and correctly and bluntly label it a fraud and hoax on the human race." "The basis of chiropractic is completely unscientific." The theory on which chiropractic is based, namely that a "subluxation" of a spinal vertebra presses on a nerve interfering with the passage of energy down that nerve causing disease to organs supplied by that nerve, and that chiropractic "adjustments" can alleviate the pressure thereby treating or preventing such disease. There is no scientific evidence for the validity of this theory."

To be fair, statements by some chiropractors have tended to perpetuate this misunderstanding: "Pressure on nerves causes irritation and tension with deranged functions as a result."

When chiropractors declare that "pinched nerves" "nerve impingement" "spinal fixations" or others mechanisms of action explain how subluxations affect the person and how chiropractic works they are making the same mistake medical critics make - assuming chiropractic is based on theory. Mechanisms and theories are useful tools, but their limitations should always be kept in mind.

Other chiropractors have declared its unproven status as an area that needs reform:

"Some may suggest that chiropractors should promote themselves as the experts in "correcting vertebral subluxation." However, the scientific literature has failed to demonstrate the very existence of the subluxation. Until and unless sound research published in credible journals demonstrates the existence and reliable identification of vertebral subluxation, and vertebral subluxation is found to be an important public health problem, society at large will not care about its correction. Thus, "subluxation correction" alone is not a viable option for chiropractic's future."

A Beth Israel Deaconess Medical Center article describes the mainstream understanding of vertebral subluxation theory:

Since its origin, chiropractic theory has based itself on "subluxations," or vertebrae that have shifted position in the spine. These subluxations are said to impede nerve outflow and cause disease in various organs. A chiropractic treatment is supposed to "put back in" these "popped out" vertebrae. For this reason, it is called an "adjustment."

However, no real evidence has ever been presented showing that a given chiropractic treatment alters the position of any vertebrae. In addition, there is as yet no real evidence that impairment of nerve outflow is a major contributor to common illnesses, or that spinal manipulation changes nerve outflow in such a way as to affect organ function.

In 2009, four scholarly chiropractors concluded that epidemiologic evidence does not support chiropractic's most fundamental theory. Since its inception, the vast majority of chiropractors have postulated that "subluxations" (misalignments) are the cause or underlying cause of ill health and can be corrected with spinal "adjustments." After searching the scientific literature, the chiropractic authors concluded:

"No supportive evidence is found for the chiropractic subluxation being associated with any disease process or of creating suboptimal health conditions requiring intervention. Regardless of popular appeal, this leaves the subluxation construct in the realm of unsupported speculation. This lack of supportive evidence suggests the subluxation construct has no valid clinical applicability."