Following the Guidelines of Science: A Chiropractic Dilemma

Preamble: When my book Bonesetting, Chiropractic, and Cultism [full text] was published in 1963, renouncing chiropractic vertebral subluxation theory and recommending that chiropractic be developed as a subspecialty of medicine in the treatment of mechanical-type back pain, the chiropractic profession refused to acknowledge or review the book. I was labeled “an enemy of chiropractic.” If it had not been for the support I received from the science-based community, I might have had doubts about my mind set and my motives. Favorable reviews by members of the science-based community sustained me over the years; for that, I am deeply grateful. Today, still unheard by the chiropractic profession, the message of my Bonesetting book remains relevant in describing the problems of chiropractic. Although out of print, the entire book can be read online on


The Aftermath of Bonesetting, Chiropractic, and Cultism, 1963

In view of the absence of any extensive histories of chiropractic, this book has a place in medical collections and reference libraries. ─ Eric Meyerhoff, Director, The Medical Library Center of New York, N.Y.C., Library Journal, February 1, 1964

In regard to your recent application for membership in the American Chiropractic Association and insurance in the National Chiropractic Insurance Company, please be advised that the ACA membership committee has rejected your application. ─ H.W. Pruitt, D.C., Executive Secretary, American Chiropractic Association, May 17, 1965

I purchased your book some months ago on Bonesetting, Chiropractic, and Cultism. I found it to be a most intriguing and enlightening publication which has been of value to me in some of my own studies in medical anthropology. ─ James G. Roney, M.D., Ph.D., Stanford Research Institute, November 11, 1965

I was more impressed by your criticisms of chiropractic than by those of any other writer, since you are a practicing chiropractor. I think every candidate for chiropractic college should read your book, or at least every student in his first year. ─ Walter Wardwell, Ph.D., Professor of Sociology, University of Connecticut, August 26, 1976

Thank you for your book Bonesetting, Chiropractic, and Cultism. I found it well-written and most interesting. I have read quite a bit of material on the chiropractic controversy by authors on all sides of the issue. I rank your book among the very best. ─ William Jarvis, Ph.D., Associate Professor, Loma Linda University, October 22, 1976

I just re-read your chiropractic book and enjoyed it even more than I did five years ago. Your reasoning and predictions have held up remarkably. ─ Stephen Barrett, M.D., Lehigh Valley Committee Against Health Fraud, July 28, 1979

Unfortunately unknown to most chiropractors, and unavailable at many if not most chiropractic college libraries, Bonesetting, Chiropractic, and Cultism is must reading for chiropractic historians….Perhaps the profession will finally seek out this seer before his most dire predictions come to pass. ─ Joseph Keating, Ph.D., Professor, Palmer College of Chiropractic-West, Dynamic Chiropractic, January 3, 1990

Fifty years ago, you already expressed some of the things few dare write today! If chiropractic had had more people like you early on, it would be a respectable profession today. ─ Edzard Ernst, M.D., Ph.D., Professor, Peninsula Medical School, England, January 12, 2010

“…the Main Trouble with Chiropractic Is Chiropractic Itself.”
(Bonesetting, Chiropractic, and Cultism, 1963)

This morning, I saw an advertisement by a chiropractor who claims that he has had “great success” treating patients suffering from chronic illnesses and neuropathy. He treats patients by adjusting misaligned vertebrae to “relieve pressure on nerves and restore whole body wellness.”

Unfortunately, such advertisements are common and unchallenged, reflecting a theme typical of a pseudoscientific alternative healing method.

I don’t know of any reason to believe that adjusting a misaligned or “subluxated” vertebra to remove nerve interference will improve health or cure an organic ailment. If you follow the guidelines of science, the chiropractic vertebral subluxation theory appears to be a tenuous belief system, far removed from a legitimate theory based on accepted knowledge that can be studied or explained. When I was being taught subluxation theory in chiropractic college, the anatomy and physiology textbooks I studied led me to question subluxation theory. It quickly became apparent to me that the body’s organs are innervated primarily by autonomic nerve ganglia and plexuses located outside the spinal column, supplied largely by autonomic cranial and sacral nerves that pass through solid bony openings and by preganglionic spinal cord fibers. The very important vagus nerves traverse openings in the base of the skull and travel down to supply thoracic and abdominal organs. Overlapping autonomic nerve supply from many directions and sources, along with chemical, hormonal, and circulatory factors, assures function of the body’s organs, unaffected by a segmental dysfunction (subluxation) and independent of spinal nerves that are designed primarily to supply musculoskeletal structures. Spinal nerves are commonly compressed by disc herniation and osteophyte formation, affecting the peripheral and musculoskeletal structures they supply, but such “pinched nerves” have never been associated with ill health or organic disease.

Despite increasing educational requirements for enrollment in a chiropractic college and inclusion of adjunctive treatment methods in chiropractic care, the basic principles of chiropractic have not changed much, persisting largely because of their simplicity in attracting and educating patients. Locating a “subluxation” in the spine and then pointing to a nerve chart linking the subluxation to an organ or a disease process rarely fails to impress a prospective patient. Adjusting the spine to produce a pop that signals correction of an alleged subluxation, or simply telling the patient that a subluxation has been corrected, is a powerful form of suggestion that produces a placebo effect.

Clinging to the theory that gave the chiropractic profession birth and independence, chiropractic associations and state laws continue to define chiropractic as a method of adjusting vertebral subluxations to restore and maintain health, guided by a modified version of vertebral subluxation theory (“vertebral subluxation complex”) to justify a broad scope of practice. A 2010 publication of the National Board of Chiropractic Examiners (NBCE), Practice Analysis of Chiropractic, states that “The specific focus of chiropractic practice is known as the chiropractic subluxation or joint dysfunction. A subluxation is a health concern that manifests in the skeletal joints, and, through complex anatomical and physiologic relationships, affects the nervous system and may lead to reduced function, disability, or illness.” This definition of chiropractic is in keeping with a paradigm formulated by the Association of Chiropractic Colleges (ACC) in 1996, signed by 16 North American chiropractic college presidents: “Chiropractic is concerned with the preservation and restoration of health, and focuses particular attention on the subluxation.”

Such subluxations have never been proven to exist. A review of web sites and advertisements sponsored by recent graduates of chiropractic colleges, however, reveals that subluxation-based chiropractic care is still very much in vogue. A 2011 study reported that “Despite the controversies and paucity of evidence the term subluxation is still found often within the chiropractic curricula of most North American chiropractic programs.” (Mirtz & Perle. The prevalence of the term subluxation in North American English-Language Doctor of Chiropractic programs. Chiropractic and Manual Therapies. 2011;19:14)

Many students enrolling in chiropractic colleges today have undergraduate degrees. How can a chiropractor with a bachelor’s or master’s degree in science subscribe to what appears to be a scientifically indefensible subluxation theory?

Critical Thinking vs. Pseudoscience

Many people with a good education profess support for views based on a belief system, especially in the areas of healing and religion. I suspect that some advocates of pseudoscience are not capable of critical thinking and are simply products of the most persuasive voice they hear. An inherent ability to reason and think independently may be more important than an academic degree in the makeup of a science-based skeptic. In my own profession as a chiropractor, I was often amazed to see chiropractors with advanced academic degrees touting vertebral subluxation theory. While some of these practitioners were undoubtedly marketing a belief system for economic reasons, fully aware of the impropriety of their actions, it appeared to me that some of them were well-meaning but misinformed or simply did not understand what they had been taught.

In 1998, the year of my retirement, the January issue of the American Medical Association’s Archives of Family Medicine published my article, “Finding a Good Chiropractor,” designed to help family physicians distinguish between the good and the bad in the use of manipulation by chiropractors. My book Inside Chiropractic, A Patient’s Guide, was published by Prometheus Books in 1999. I explained why I thought the chiropractic subluxation theory was false. I supported use of generic spinal manipulation as a modality in the treatment of some types of back pain. Unlike homeopathy and some other dubious healing methods that have no value whatsoever beyond a placebo effect, spinal manipulation as a form of manual therapy has some plausible basis for relieving back pain and restoring mobility.

Speaking Out Against Nonsense

I wrote many articles critical of chiropractic and subluxation theory. The biggest splash of all came when the April 2001 online edition of Medscape General Medicine published my article “Is the Chiropractic Subluxation Theory a Threat to Public Health?” previously published in the winter 2001 issue of Scientific Review of Alternative Medicine. I was inundated with hate mail. A spokesperson for the American Chiropractic Association described my article as “outdated and inaccurate” and asked Medscape to remove the article from their website. In September of 2005, Clinical Orthopaedics and Related Research, a leading peer-reviewed journal for orthopedic surgeons, published my article “Chiropractic: History and Overview of Theories and Methods,” a review that took a critical look at chiropractic based on subluxation theory.

Apparently reflecting the views of the majority, chiropractic associations have not renounced subluxation theory. Failure of the chiropractic profession to make the changes needed in the curriculum of chiropractic colleges to define the practice of chiropractic as a properly-limited specialty has kept the profession marginalized and mired in pseudoscience. Development of chiropractic as a physical-treatment method sans subluxation theory would lead to appropriate legal definitions of chiropractic. But the simplicity of chiropractic subluxation theory and its public appeal may make it difficult to change state laws in order to eliminate judiciary support for “adjusting vertebral subluxations to restore and maintain health.” If subluxation theory is not rejected by a chiropractic majority that is supported by public opinion, subluxation-based chiropractic will be perpetuated along with homeopathy, acupuncture, naturopathy, naprapathy, and other questionable but legally licensed alternative healing methods.

(Three states allow licensing of an MD or a DO as a homeopathic physician, but many states allow licensed health-care providers such as chiropractors and naturopaths to use homeopathic remedies. Forty-four states and the District of Columbia license practitioners of acupuncture and oriental medicine, all of which is considered to be within the scope of practice of most health-care providers, especially chiropractors. Naturopathic physicians are licensed in 16 states, the District of Columbia, and the U.S. territories of Puerto Rico and the Virgin Islands. Naprapathy, founded in the early 1900s by a chiropractor, advocates manipulation of joints and muscles to correct problems alleged to be caused by connective tissue disorders. Naprapathic physicians are licensed only in Illinois and New Mexico. There appears to be no shortage of practitioners who practice “alternative medicine,” which seems to be gaining public acceptance under the label of “complementary” or “integrative” medicine, reflecting public demand for nonsensical care along with conventional medical care.)

It has been estimated that “Chiropractors perform about 90 percent of manipulation in the United States” (The Appropriateness of Manipulation and Mobilization of the Cervical Spine, RAND, 1996). With the public equating use of manipulation with chiropractic care, manipulation in general has been stigmatized by its association with chiropractic subluxation theory. Increasing use of spinal manipulation by physical therapists and orthopedic manual therapists, however, offers opportunity to bypass questionable chiropractic care when seeking appropriate treatment with spinal manipulation. Credible research, most often conducted by physical therapists, offers support for use of manipulation as part of the treatment armamentarium of physical medicine.

Critics of chiropractic should take care not to include appropriate use of generic spinal manipulation in their criticism of chiropractic manipulation based on subluxation theory. As I have said many times, manipulation used to relieve pain and restore mobility is not the same as a chiropractic adjustment used to “restore and maintain health.” An asymptomatic and undetectable chiropractic subluxation alleged to affect general health is not the same as an orthopedic subluxation, a partial dislocation that can cause musculoskeletal symptoms. Generic spinal manipulation as a form of manual therapy (and the word “subluxation”) existed long before the development of chiropractic in 1895. Hippocrates, in describing methods of reducing “dislocations” in the spine (On the Articulations), noted that “luxations and subluxations take place in different degrees.”

Choosing between Chiropractic School and Physical Therapy School

While there are undoubtedly some chiropractors who use spinal manipulation appropriately and do a good job treating mechanical-type neck and back pain, I would not recommend that anyone enroll in a chiropractic school where there might be indoctrination in a belief system that is rejected by the scientific community and shaded by societal suspicion. Some chiropractic colleges are less subluxation-centered than others but may embrace controversial alternative healing methods. A properly limited chiropractor who might be a graduate of one of the better chiropractic schools, and who is aware of his or her limitations, would be forced to endure the nonsense and the competition of licensed unscientific alternative healers and subluxation-based chiropractors who set the standards, ostracizing nonbelievers and alienating the cooperation of mainstream health-care professionals.

Persons interested in studying manipulative therapy would be best served by going for a Doctor of Physical Therapy (DPT) degree that would allow interaction with the scientific community in researching and performing manual therapy without the stigma associated with chiropractic. At the present time, 47 states and the District of Columbia permit direct access to services provided by physical therapists, allowing private practice that fits in with mainstream health care.

All things considered, with the status and the future of chiropractic in doubt, I would not think that any well informed person following the guidelines of science today would choose to be a Doctor of Chiropractic rather than a Doctor of Physical Therapy.

When confronted with two courses of action I jot down on a piece of paper all the arguments in favor of each one─then on the opposite aside I write all the arguments against each one. Then by weighing the arguments pro and con and canceling them out, one against the other, I take the course indicated by what remains.

─ Benjamin Franklin, circa 1732


Samuel Homola is a retired chiropractor whose practice was limited to care of back pain and related musculoskeletal problems. He is a co-host of and the author of 15 books, including Inside Chiropractic, edited by Stephen Barrett, M.D., medical editor for Prometheus Books.


Posted in: Chiropractic

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13 thoughts on “Following the Guidelines of Science: A Chiropractic Dilemma

  1. windriven says:

    A fine piece on which to end the week. The emperor has no clothes but Sam Homola points to a fine haberdashery just down the block.

  2. DevoutCatalyst says:

    Sam, you look dapper. Thanks for putting the text online, used copies of your book sell for quite a bit these days.

  3. Janet says:

    Thanks for answering a question (why be a chiropractor when you can be a PT in the same amount of time?) I keep posing here and elsewhere. Your advice to go for the DPT and be a real and contributing health care professional is rational and I cannot imagine what any aspiring chiropractor could have against it–except a desire to “integrate” other sorts of quackery into his or her “practice”.

    One thing I like about PT is that the rx for the therapy comes from the MD who has looked at the problem first with an eye to the real “whole patient” (as opposed to the “holistic” nonsense gambit). Also, I don’t have to waste a lot of time trying to find the one chiro in town who operates on your principles instead of the “anything goes” that (based on signs in windows and websites) approach of most of them.

    Does anyone know if there is a parallel in the development of optometry as an adjunct to?ophthalmology? Did optometrists start out doing something other than screening and lens rx?

  4. pharmavixen says:

    Thank you, Sam, for clarifying the divide between chiropractic practice and physio. I have friends who swear by their chiropractors, and out of concern for their vertebral arteries I say to them, don’t let your chiro crack your neck. But I have hesitated to decry all chiropractors as quacks, as some of my evidence-based medicine friends like to do, because many of the practices described by my chiro-visiting friends sounds just like physiotherapy.

    You also make excellent points about how some people with a science education will embrace pseudoscience. As someone who studied for a bachelor of science in the 1980s and graduate school more recently, I have observed that it’s possible for students to achieve very high levels academically without critical thinking, if they have a good work ethic, a decent memory, and a knack for problem-solving, like the sort of people who are good at chess. If they continue to progress up the academic ladder, you’d think they’d eventually acquire a more profound understanding of the conceptual underpinnings of what they are studying. But not necessarily, hence the Linus Pauling disgrace-your-legacy-as-a-Nobel-laureate phenomenon.

  5. Adam Rufa says:

    Dr. Homola,

    Thank you for laying out this issue so well. I commend you for taking the risk of speaking out against your own profession. I am sure it has been a difficult road at times.


    The days are past (mostly) where PTs are given a “prescription” from the MD. It is true that despite our ability to see patients via direct access, most of the time patients still see a physician first. However, the appropriateness of treatment and the details of the treatment are the responsibility of the PT.

    We are also trained well in differential diagnosis and as a whole are very good at differentiating between MSK and non MSK problems. With that being said, I for one greatly value my collaborations with MDs and feel that a team approach often leads to the best outcomes.

  6. tgobbi says:

    Over the years I’ve developed tremendous respect for Sam Homola. We’ve not met but there have been email exchanges from time to time and I’m pleased to say that we’re in agreement about what chiropractic is and what it isn’t. (Well, maybe my views are somewhat more extreme than his, but that’s just a matter of quantity – not quality. My respect stems from at least two areas: his insider’s view of a shamefully and unapologetically pseudoscientific, and potentially dangerous, faux healthcare modality; and his resolute courage in facing up to his adamantly pro-status quo colleagues/opponents/detractors.

    I believe it’s clear to anyone who has read my comments on this forum that my opinion of chiropractic is less than favorable (BIG understatement). I’ve bantered back and forth with numerous true-believer DCs over the past three decades and have encountered numerous ad hominem attacks directed at Sam. Generally this arises when I quote or cite his criticisms of the pseudoscientific aspects of the field. At the very least his critics dismiss him as “not really a chiropractor,” in my opinion an impeachment of his refusing to adhere to the “cause.” Indeed this says more about his critics than it does of him.

    What’s really distressing is that Sam began his crusade many years ago at a time when there still may have been a modicum of hope that chiropractic could have been saved from itself. Alas, he preached not only to deaf ears, but to ears attached to profoundly antagonistic fanatics who were bound to retain the status quo at any cost. They tenaciously clung, and continue to do so, to a need to separate themselves from the science-based medical mainstream for no reason other than to hold onto being different. Pessimistically I must say that I think the time for reform has come and gone and that the only hope is for chiropractic to collapse from the weight of its own insularity, parochialism and stubbornness – much like what happened to the Soviet Union.

  7. Quill says:

    I add my thanks to Dr. Homola and also think this is a fine article and a concise piece to recommend to people who don’t understand chiropractic or encounter it for the first time.

    Also thanks for posting your book online. I’d not seen it there until now and am very happy to not only read it again but also recommend it to people who want to know what chiro was like in its infancy (ha!) and what it looks like now that it is still in its infancy. ;-)

  8. moderation says:

    Thanks for an article to which I can refer friends with questions about chiropractic practice.

  9. brian888 says:

    Here’s my story: As a young man trying to sort out a career, I happened upon Chiropractic and it had a real appeal to me. Luckily I tend to do a lot of researching things before making important decisions and so I looked very closely at chiropractic. I visited several of their colleges, interviewed and observed 4-5 practicing chiropractors, and read what I could find. This was at a time just before the internet was so robust and so it was hard to find too much objective information on the subject. What I learned from my analysis made me come to the difficult decision that I was about to launch myself into something that was filled with charlatans and nonsense. The final straw that made me finally come to the conclusion to leave it all behind was a book called “Chiropractic: the Victim’s Perspective” by George Magner. After that, I understood that dogma and lies on which chiropractic was built and continues to depend upon. This process of discovery is also what led me to begin critical thinking/ skepticism, and it has benefited me immensely ever since. I saw that I would very likely be quite unhappy had I continued with my plans in chiropractic. As the author suggests, I ended up getting my DPT (12 yrs ago now). The now standard doctoral-level education of physical therapists will slowly erode the supply of would-be “doctors” who previously sought the chiropractic path as one of the only viable means to achieve this status that they so desire due to their family and societal desires to be recognized. Physical Therapy is vastly superior to Chiropractic as far as education and as a profession. But physio too has some traditional practices which it needs to drop, and even with the strong push towards EBM has still been slow to jettison some unproven therapies (ultrasound, etc.). But still, to any young person contemplating the two careers, I’d strongly suggest you look into chiropractic and not buy the propaganda that is so prevalent. Sites like this and will lead you to a much improved understanding of the truth behind pseudoscience like chiropractic. And thank you to men like Dr. Homola, Dr. Jarvis, Dr. Barrett, and Dr. Novella!

  10. Sam Homola says:

    Thanks. The positive comments received in response to my article make it all worthwhile!


  11. gbove says:

    Hey Sam — All over, great stuff here. But you should know the emerging literature! Call me, 207 590 8949.

  12. The Dave says:

    Instead of requesting a personal call, why don’t you share it out in the open right here in the comments, so we can all benefit from “the emerging literature”?

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