Chiropractic: Science or Pseudoscience?

By Jacob Burgess


When is it appropriate to deem a practice as pseudoscientific? Philosophers and scientists in the past have struggled to come up with a theory that can accurately condemn pseudoscientific practices as unscientific without ruling out other clearly scientific practices in the process. Theories such as the verifiability and falsifiability criterion have been proposed, but these theories have been met with a considerable amount of criticism. In his paper “Why Astrology Is A Pseudoscience,” Paul R. Thagard proposes his own principle of demarcation. He claims that in order for a theory or discipline to be deemed pseudoscientific, it must fail under the following criteria:


  1. [The theory] has been less progressive than alternative theories

over a long period of time, and faces many unsolved problems;

  1. but the community of practitioners makes little attempt to develop the theory towards solutions of the problems, shows no concern for attempts to evaluate the theory in relation to others, and is selective in considering confirmations and disconfirmations.


I believe these criteria are sufficient to condemn chiropractic as a pseudoscience, but before we examine the practice under Thagard’s principle of demarcation, it is necessary to give a brief synopsis of the history and ideas behind chiropractic.


Daniel David Palmer founded chiropractic in the year 1895 in Davenport, Iowa. Palmer theorized that all disease was the result of interruptions in the body’s “innate intelligence”, which is a vitalistic life force that represents God’s presence in humanity. Our innate intelligence, Palmer claimed, is what allows the body to heal itself. Through the realigning of vertebral joints (which interrupt our innate intelligence when out of place), the body can be cured of virtually all diseases. Palmer termed these vertebral joint misalignments “vertebral subluxations” and proposed the spinal manipulation theory (SMT) as a method of treatment.


Although vertebral subluxation remains a core concept in traditional chiropractic, the community of practitioners has become divided. Those who still adhere to the traditional principles of chiropractic are known as “straight” chiropractors, and those who use treatments and techniques from other areas of alternative and modern medicine are known as “mixer” chiropractors. Many mixer chiropractors still believe subluxation to be a large contributing factor to poor health, but they are often open to other possible causes of disease and will sometimes use conventional treatments such as stretching, massaging, exercise, and other physical therapy techniques. Some mixer chiropractors will also use techniques from different areas of alternative medicine, including acupuncture, homeopathy, herbal remedies, and nutritional supplements.


Now let us examine chiropractic under Thagard’s demarcation principle. While some chiropractors are skeptical of the many dogmatic elements within the practice, a 2003 survey of 1100 North American chiropractors found that 88% wanted to retain the term “vertebral subluxation” and 62% believed that subluxation was a major contributing factor to internal organ disorders. This is problematic if chiropractic is to be considered a scientific practice, as there is virtually no scientific evidence supporting the effect vertebral subluxation has on internal organs. D. D. Palmer initially defined vertebral subluxation as follows:


“A (sub)luxation of a joint, to a Chiropractor, means pressure on nerves, abnormal functions creating a lesion in some portion of the body, either in its action, or makeup.”


Subluxation was initially believed to be a partial dislocation of the bones. This was shown to be erroneous when x-rays were invented, but instead of abandoning the theory, chiropractors simply redefined it as “a complex of functional and/or structural and/or pathological articular changes that compromise neural integrity and may influence organ system function and general health.” This differs greatly from the medical definition of subluxation as a significant displacement that can be detected using x-rays. The fact that the majority of chiropractors refuse to dismiss the concept of subluxation despite a significant amount of evidence refuting their claims demonstrates that the theory has been less progressive than alternative theories. Thus, chiropractic fails under Thagard’s first criterion.


While some practitioners utilize techniques from other medical practices, the majority of chiropractors still use techniques that are not based in scientific evidence. There is a lack of evidence to demonstrate that chiropractic is an effective treatment for any kind of medical condition (with the exception of particular kinds of back pain). There are many alternative techniques used by physical therapists that have been proven to have positive results for conditions chiropractors attempt to treat, and yet chiropractors continue to employ unscientific methods to patients suffering from these conditions. Furthermore, chiropractic research has often been accused of being distinctly biased. Therefore, chiropractic fails under Thagard’s second criterion.


According to Thagard’s principle of demarcation, we can now appropriately deem chiropractic a pseudoscience. Chiropractic fails to provide solutions to medical conditions that are more effective than mainstream medical treatments, and the majority of its practitioners appear to be utterly obstinate in their positions on vertebral subluxation.


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