published 10/9/06, updated 11/23/09

Does Chiropractic Work?

Notes from a science-minded massage therapist who gets asked about it every day

by Paul Ingraham, Vancouver, Canada MORE
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Credentials and qualifications

I am a writer and retired Registered Massage Therapist (unusually well-trained for a massage therapist, a 3000-hour program). I’m almost done with a Bachelor of Health Sciences degree. I am a peer reviewer for The Natural Standard, and a copyeditor for Science-Based Medicine. My most important qualification is more than a decade of workaholic post-graduate study, clinical experience, and constant conversations with readers from around the world, including many experts who have provided countless suggestions and criticisms.

For more information, see: Who Am I to Say? More information about my qualifications, credentials and professional experiences for my readers and customers.

A 2006 Gallup Poll found that chiropractic rated dead last among health professions with regard to ethics and honesty.1 Why? My clients are curious about the poor reputation of chiropractic, and confused about the nature of chiropractic.2 Often inspired by their own negative experiences, they ask me what I think.

This article is a survey of chiropractic controveries and issues that patients should be aware of.

I actually pay for chiropractic therapy myself on occasion, and I do recommend some chiropractic therapy to my patients. At the same time, I respect the judgement of many expert critics who believe that, “The concepts of chiropractic are not based on solid science and its therapeutic value has not been demonstrated beyond reasonable doubt.”3

“Does chiropractic work?” is the wrong question

The first thing one wants to know about any treatment — alternative or otherwise — is whether it works. Until that is decided, all talk of qualifications, regulation, and so on is just vacuous bureaucratese.
Dr. David Colquhoun, “Doctor Who? Deception by chiropractors”

And yet “chiropractic” is many things. Does chiropractic work for what? Does what kind of chiropractic treatment work? How much treatment?

Asking if “chiropractic works” is not specific enough to have a clear answer. It is not really a fair question to ask of chiropractic as a whole. But it is nevertheless the question that people ask, and so we have to deal with it as well as we can.

I believe it’s obvious that some chiropractic therapy does “work” in certain ways, for some people, some of the time. But the most important factor in the usefulness of chiropractic therapy is not the nature of chiropractic as a profession, but the skill and good sense of the particular chiropractor whose hands are on your neck. Ethical, intelligent practitioners of any helping profession will always deliver better care than less competent members of their own or any other profession. It’s important to Choose the Therapist, Not the Therapy. Consumers need to be aware of the issues to help them choose a chiropractor.

The best consumer guide to chiropractic therapy available, written by a chiropractor and America’s leading expert on pseudoscientific health care. If you want to know if chiropractic therapy “works,” stop reading my article and go get this book.

Am I qualified to criticize chiropractic?

No! And so I don’t. What I will do is summarize the issues in a readable way, and quote the experts who are qualified, and cite some of the same scientific evidence that they do. I’m just another health care professional, with no special knowledge or experience with chiropractic. Furthermore, I have no wish to re-invent the wheel: there are already many excellent books available on this topic (see the further reading section at the end of the article). This is a quick tour of the topic, not a tour de force.

Judging the value of chiropractic therapy is best left to the experts who have already done it, to the progressive chiropractors and critics from within the profession like Dr. Samuel Homola4 and Dr. Donald Murphy;5 progressive chiropractic regulatory agencies like the Chiropractors Registration Board of Victoria in Australia;6 activist physicians like Dr. Stephen Barrett,7 Dr. Stephen Novella,8 or the especially credible Dr. Edzard Ernst9 (who has such great experience with both medical science and alternative therapies); and science journalists like Simon Singh,10 who is in the news lately because he is being sued for libel by the British Chiropractic Association for comments he wrote in a column in The Guardian in 2005, in connection with his book, Trick or Treatment: The Undeniable Facts About Alternative Medicine.11

An introduction to chiropractic controversies

Whatever anyone thinks about chiropractic, there is an undeniable history of scientific controversies swirling around the profession, from it’s earliest days to the present. What are those controversies?

Chiropractic often involves many expensive but quick treatments,12 13 as well as marketing that some people consider to be aggressive and distasteful. Do chiropractors oversell their services?
The original “big idea” of chiropractic was that nearly any health problem can be cured by spinal manipulation. Today, many chiropractors still recommend chiropractic therapy for many problems beyond just low back and neck pain. Is this reasonable? Is there any scientific evidence that chiropractic therapy can prevent, help or cure a wide variety of diseases and ailments?
Adjustment of the neck could be a cause of severe injury and death. There are numerous class action lawsuits against chiropractors and chiropractic professional organizations for this reason.14 Is there a risk? Considering the stakes, is any risk acceptable? A large group of Canadian neurologists asks, “Is a headache worth dying for?”15

I’m not answering these questions here — I’m just asking them! And I’m pointing out that they have been asked (and answered) for decades. Many credible critics rule against chiropractic on all of these issues and several others.

And while you might think that all chiropractors would defend themselves against these accusations, that’s not even the case. In fact, many chiropractors are also critical of common chiropractic beliefs and practices. Thus, one of the most important things to understand about chiropractic is that it is a divided profession: there is significant controversy within the profession itself.

Chiropractic is a divided profession

The chiropractic profession was founded about a century ago by Daniel David Palmer. Chiropractic owes its existence to this one unusual man and his son — always referred to as “D.D.” and “B.J.” palmer — whose ideas remain the foundation of the profession today. Both DD and BJ were colourful characters, and were arguably marketing geniuses. DD in particular was known for his extravagant ego. Here’s an entertaining example of his flamboyant personal style:

I was the first to adjust the cause of disease .... The man who had the intellectual capacity to comprehend the displacement of the vertebrae; the mental abability to grasp the significance of nerve impingement; the power to conceive and discriminate between normal and abnormal positions; the foresight and wisdom to discern the outcome; the genius of originality to create such a unique science; the judgement needed for the occasion; the brain caliber of reasoning on this heretofore perplexing question — the cause of disease; the sense of touch required to discover a racked vertebra and the skill and tact to replace it, was the one destined to discover and develop the science which he named chiropractic.
Shall Chiropractic Survive?, by BJ Palmer

Wow. Clearly, DD’s arrogance was dialed up to 11.

According to DD Palmer, “A subluxated vertebra … is the cause of 95 percent of all diseases.”16 Those were big words, and indeed they have been called the “big idea” in chiropractic ever since. In 1966, a group of physicians damningly wrote, “In all the years that they have been talking about them, chiropractors have never been able to furnish proof of these mysterious subluxations which they alone are able to see. They may convince their clients, but never have they provided proof of their pretensions to men of science.”17

Today, some chiropractors reject subluxation theory:

Chiropractic, which celebrated its centennial in 1995, is a curious mixture of science and pseudoscience, sense and nonsense. Much of it is based on the theory that misaligned spinal bones produce nerve interference that causes disease. Many chiropractors claim that correcting these misalignments (“subluxations”) can restore health and that regular spinal adjustments are essential to maintain it.

Neither logic nor scientific evidence supports such a belief. Although spinal manipulation can relieve certain types of back pain, neck pain, and other musculoskeletal symptoms, there is no scientific evidence that it can restore or maintain health. As a result of expressing my opinion on this subject, I have been called a chiropractic heretic.

The chiropractic profession has little tolerance for dissension. Its nonsense remains unchallenged by its leaders and has not been denounced in its journals. In fact, many chiropractic journals continue to publish articles that attempt to justify subluxation theory. Although progress has been made, the profession still has one foot lightly planted in science and the other firmly rooted in cultism. Without appropriate criticism, the good in chiropractic will never be sifted out, and competent chiropractors will not receive the recognition they deserve.

This book denounces the cultism in chiropractic but supports the appropriate use of spinal manipulation and the research efforts required to solidify its scientific basis. If you are contemplating or receiving chiropractic care, it might help protect both your pocketbook and your health.
Inside Chiropractic, by Samuel Homola, pvii

This controversy between chiropractors themselves is highly relevant to the consumer. The profession is divided between chiropractors who still embrace subluxation theory (known as “straight” chiropractors), and those choose to limit their expertise and therapy to musculoskeletal health, especially spinal care (known as “mixers”).18 A chiropractic college instructor writes of this “well-known division between ‘straights’ and ‘mixers’” that “we are at risk of returning to the antiscientific and dogmatic traditions that we have worked so hard to shake off during the past several decades.”19

If you go to a chiropractor, you’d probably like to know what kind of a chiropractor is treating you, regardless of your own opinion about this controversy. Whether you prefer a “straight” or a “mixer,” you would probably prefer to know what sort of chiropractic therapy you are getting.

Unfortunately, it is difficult for patients to tell which is which.

Spinal manipulative therapy (SMT): Adjustment, manipulation and cracking of the spinal joints

The idea of “adjusting” the spine refers to many different manual therapies that wiggle, pop and otherwise manipulate spinal joints. The correct umbrella term for these treatments is “spinal manipulative therapy” or SMT. Expert opinions on SMT range widely, with some prominent medical scientists expressing strong concerns, primarily because its provenance in chiropractic subluxation theory is dubious, but also because whatever benefits it has are clearly not major, and there are serious risks, even including paralysis and death in the case of SMT for the joints of the neck. For more information about the risks of treating the neck, see What Happened To My Barber? Either atlantoaxial instability or vertebrobasilar insufficiency causes severe dizziness and vomiting after massage therapy, with lessons for health care consumers.

Despite all the controversy, there has been little high quality scientific research to determine whether or not SMT is safe and really works. Major reviews of that literature published in recent years came to underwhelming conclusions,20 21 and recent experiments continue to damn SMT with faint praise, showing that it works … a little.22 Thus, SMT fails the “impress me” test — it certainly isn’t working any miracles.

And yet spinal joint popping in particular is something that people crave, and most clinicians — including myself, and including skeptics like Dr. Homola — believe that some forms of SMT can be helpful to some of their patients, some of the time. There seems to be almost no doubt that there is something of therapeutic interest going on in SMT.

There is no definitive evidence that spinal manipulative therapy is more effective than other forms of treatment for patients with acute or chronic low-back pain. However, manual therapists know from experience that spinal manipulation is often more effective for providing immediate short-term relief for some types of back pain.

“Can Chiropractors and Evidence-Based Manual Therapists Work Together?”

Scratching the itch you can’t reach: why joint popping feels good and possibly relieves pain

Occasionally I recommend chiropractic therapy to my own patients. Sometimes I believe my clients need more skilful and direct stimulation of spinal joints than I can provide myself, and I believe that the scientific evidence shows that approriate spinal manipulation has the potential to help back pain in this way, with acceptable risks.

Many of my own clients have reported this kind of positive result from chiropractic treatment. I have experienced it myself on many occasions, and I have also observed many clients expressing relief and pleasure in response to incidental spinal “adjustments” — joint pops that occur in the course of doing massage therapy, little explosions as I glide up the spine.

Many people seem to feel that a happy spinal adjustment feels like “scratching an itch you can’t reach.” Why might that be?

Whatever you have been told before, and despite the availability of many explanations on the internet, the nature of joint popping is not well understood.23 It is firmly in that category of trivial mysteries for which there is simply no research funding, and as such it will probably remain unexplained for some time to come. We simply do not know.

Whatever a joint pop really is, it probably providees a novel sensory experience: a little blast of proprioceptive stimulation.24 Since all living systems seem to thrive on sensory input, and generally suffer without it, I speculate that a joint crack essentially feels like getting “unstuck,” and is analogous to finally getting to stretch your legs after getting off a long flight — which is not intended to trivialize it.

The strength of this idea is that it just isn’t claiming much: it both accounts for the extremely satisfying feeling that many people report, but without promising the moon. Indeed, it also seems consistent with another widely reported feature of SMT: the benefits often don’t last long! Soon the “itch” needs to be “scratched” again. It also could explain why the benefits of SMT are so variable and uncertain: it is highly dependent on many factors. For instance, whether a joint crack feels “refreshing” to you depends on how you feel about the whole idea of joint cracking.

The fear of spinal adjustment

Unfortunately, many people are not comfortable with having their spinal joints “cracked” or manipulated.

This is one of those “there are two kinds of people in the world” things: some people crave spinal joint cracking, expertly applied or otherwise, and to others it seems like fingernails on a chalkboard. My wife, for instance, wants at least one spine-cracking hug per day, and clearly becomes impatient when it has been too long since the last one! Other people would view such a hug as an alarming assault — people with such anxiety about spinal joint popping typically have never been to chiropractor and never will, or they take a dim view of what happened to them when they reluctantly tried it.

“I will never let a chiropractor touch me again” is just as common a patient report as “I have to get adjusted at least once a month.”

Clearly, those who find joint cracking to be unpleasant are not good candidates for “scratching the itch” with a nice round of lumbar facet joint explosions! You know who you are, and you don’t really need to be reading this: chiropractic is certainly not going to work for you!

Notes

Gallup poll: Americans have low opinion of chiropractors' honesty and ethics. ChiroWeb.com. 2006. Return to text.
Homola. Archives of Family Medicine. 1998. Chiropractic is a puzzling profession because, according to Sam Homola, a chiropractor himself, it “is one of the most controversial and poorly defined healthcare professions with recognition and licensure … it has the confusing image of a back specialty capable of treating a broad scope of health problems.” Return to text.
Ernst. Journal of Pain and Symptom Management. 2008. Return to text.
Samuel Homola, Doctor of Chiropractic, is a second-generation chiropractor who has dedicated himself to defining the proper limits on chiropractic and to educating consumers and professionals about the field. He is hardly the only critic of his own profession, but he is probably the most famous and widely read. His 1963 book, Bonesetting, Chiropractic, and Cultism, supported the appropriate use of spinal manipulation to treat some spinal pain but renounced the common chiropractic dogma that spinal adjustment is a panacea. I strongly recommend his 1999 book Inside Chiropractic: A Patient’s Guide. It provides an incisive look at chiropractic’s history, benefits, and shortcomings. Return to text.
How Can Chiropractic Become a Respected Mainstream Profession? The Example of Podiatry. Murphy et al. 2008. Dr. Murphy is one of five research-oriented chiropractors that have bared their profession’s shortcomings in a 2008 article that calls for “dramatic changes” and states that chiropractic “finds itself in a situation in which it is rated dead last amongst healthcare professions with regard to ethics and honesty.” This readable document is an excellent survey of the problems with the chiropractic profession. Return to text.
In 2008, THE CRBV proposed new standards that attack common chiropractic beliefs and practices, particularly in the case of treating children. Although perhaps not obviously “fightin’ words” to the general public, within the world of therapy the CRBV’s proposal is a strong attack on the philosophical foundations of subluxation-based chiropractic: “There is currently an overwhelming lack of good quality scientific evidence to support the use of spinal manipulation in the treatment of [disease]. Non-indicated, unreliable and invalid diagnostic tools, instruments or methods and unnecessary diagnostic imaging procedures are to be avoided.” The draft document goes on to condemn unnecessary X-ray examination, especially for children, and the use of surface electromyography (SEMG) or thermography for diagnosis. These common diagnostic methods are described as “innappropriate.” I think that such opinions are both credible, given the source, and of great concern. And this CRBV is hardly the only chiropractic regulator responding to a need to clamp down on such pratices — it is just a good recent example. Return to text.
Dr. Stephen Barrett, a retired psychiatrist, is America’s most prominent scientific medicine activist. (I am pleased to know Dr. Barrett a little bit myself, having exchanged several notes with him over the years, and spoken with him at some length on the phone on one occasion.) In addition to founding the prominent websites QuackWatch and Chirobase, Dr. Barrett operates 23 websites in all; edits Consumer Health Digest (a weekly electronic newsletter); is medical editor of Prometheus Books; and has been a peer-review panelist for several top medical journals. He has written more than 2,000 articles and delivered more than 300 talks at colleges, universities, medical schools, and professional meetings. His dozens of books include The Health Robbers: A close look at quackery in America and seven editions of the college textbook Consumer Health: A guide to intelligent decisions. Return to text.
Dr. Stephen Novella is an academic neurologist on full-time faculty at Yale University School of Medicine. That in itself would be career enough for me, but Dr. Novella is almost frighteningly productive above and beyond his professional duties at Yale. He is the co-founder and President of the New England Skeptical Society, Associate Editor of The Scientific Review of Alternative Medicine, a contributing editor of QuackWatch, author and contributor to numerous columns, blogs and podcasts, most notably the popular podcast Skeptic’s Guide to the Universe, which has many tens of thousands of listeners and is my own favourite podcast. Return to text.
Dr. Edzard Ernst possesses a rare mixture of significant expertise and experience with both scientific and so-called “alternative” medicine, and consequently has become one of the most interesting and credible experts on the subject. He qualified as a physician in Germany in 1978 where he also completed his MD and PhD theses, but has also received training in acupuncture, homoeopathy, massage therapy and spinal manipulation. His experience and research have made him one the most credible and interesting critics of alternative medicine in general, and chiropractic in particular, along with science journalist co-author Simon Singh (see below). His 2008 interview in New Scientist is an interesting introduction (see Bond). Dr. Ernst has published more than 40 books — including the current book Trick or Treatment, and last year (right up my alley) Complementary therapies for pain management — and in excess of 1000 articles in the peer-reviewed medical literature and has been given visiting professorships in Canada and the US. His work has been awarded with 13 scientific prizes. Return to text.
Simon Lehna Singh, MBE, is an Indian-British author of Punjabi background, who has specialised in writing about mathematical and scientific topics in an accessible manner. Most recently and relevant to this article and this website, Mr. Singh wrote Trick or Treatment with prominent scientist co-author Dr. Edzard Ernst (just mentioned above). Mr. Singh’s written works also include Fermat's Last Theorem (about one of the most difficult problems in mathematics), The Code Book (about cryptography and its history) and Big Bang (about the Big Bang theory and the origins of the universe). He has also produced documentaries and works for television to accompany his books, is a trustee of NESTA, the National Museum of Science and Industry.Return to text.
Simon Singh’s legal battle with the British Chiropractic Association is a good example of why I increasingly avoid criticizing chiropractors directly myself. Instead I simply refer SaveYourself.ca readers to more prominent critics who are backed by organizations and lots of academic credibility. Mr. Singh, however, is “just” a science writer fighting for the right to free speech and scientific analysis, and can use all the public support he can get: please see the Sense About Science campaign page “Sign up now to keep the libel laws out of science!” and join the Facebook group For Simon Singh and Free Speech — Against the BCA Libel Claim Return to text.
Don't Pay or Contract in Advance for Chiropractic Visits at a "Discount" Price. Barrett. 2009. In this short article, Dr. Barrett describes a range of chiropractic over-prescription practices. The bottom line is that, “Even if chiropractic treatment can legitimately help a problem, it is not possible to know in advance that a large specified number of visits will be needed.” See the next note for an example of chiropractic over-prescription. I have encountered substantial chiropractic over-prescription and “contracts” for excessive chiropractic therapy repeatedly in my own career. Return to text.
For example, consider the case of Gertrude West, a retired attorney, who sought help for knee pain from chiropractor Donald Harte in Marin County, California. Harte advised West to have intensive care for “subluxation degeneration” of her spine, and West signed 100 visits with a discount for advance payment but severe penalties for discontinuing. After 49 visits over a 4-month period, she concluded that she was not being helped and asked that payment for the unused visits be refunded. When Harte refused, she sued him. A trial judge ruled that West had been misled and the penalty clause was “unconscionable,” and this was upheld by a small claims appeals court in the spring of 2009. Return to text.
Do a Google search for “class action lawsuit chiropractic.” Return to text.
Statement of Concern to the Canadian Public from Canadian Neurologists Regarding the Debilitating and Fatal Damage Manipulation of the Neck May Cause to the Nervous System. Neck911.com. 2009. Return to text.
Palmer. The Science, Art and Philosophy of Chiropractic. 1910. Return to text.
College of Physicians and Surgeons of the Province of Quebec. The scientific brief against chiropractic. The New Physician, Sept 1966. Yes, this an old source! However, “men of science” (and women) remain unconvinced. The spirit of this statement is just as valid as it was more than forty years ago. Return to text.
Biggs et al. Journal of the Canadian Chiropractic Association. 1997. Less than 19 percent of Canadian chiropractors “reject traditional chiropractic philosophy as espoused by D.D. and B.J. Palmer and emphasize the scientific validation of chiropractic concepts and methods.” Return to text.
Keating. Journal of the Canadian Chiropractic Association. 2001. From the text: “… despite all of these genuinely progressive steps, the chiropractic profession here in North America may be slipping backwards. I perceive that we are at risk of returning to the antiscientific and dogmatic traditions that we have worked so hard to shake off during the past several decades. This apparently unrecognized reversion to the uncritical and unskeptical tendencies of early day chiropractic has everything to do with politics and economics and nothing to do with science. For more than a century chiropractors have fended off the efforts of organized, political medicine to ‘contain and eliminate’ this profession. In the process, deep rifts have formed among chiropractors. I’m not speaking here merely of the well-known division between ‘straights’ and ‘mixers,’ but more importantly about the chasm between those who would see chiropractic progress as a scientific healing art and those who are committed to old-time biotheology and ‘phoooolosophy.’ Today, chiropractors are hungry, one might even say desperate, for unity. It is this deeply felt yearning for unity, I believe, which places the scientific integrity of the profession at risk. We are at risk of accepting dogma and pseudoscience and ambiguous platitudes in order to come together.” Return to text.
Assendelft et al. Annals of Internal Medicine. 2003. This Cochrane review came to the underwhelming conclusion that “there is no evidence that spinal manipulative therapy is superior to other standard treatments for patients with acute or chronic low back pain.” It also performed no worse, though, and was more effective than fake interventions. Return to text.
Bronfort et al. Spine. 2004. This large and complex review comes to no firm, simple conclusions. It presents tentative evidence that some kinds of SMT are probably effective under some conditions. <#comments#> Return to text.
Jüni et al. Annals of the Rheumatic Diseases. 2009. In this reasonably good test of SMT, researchers took a hundred patients with nasty, fresh cases of low back pain, and delivered half of them into the care of chiropractors, and the other half into “standard care” — advice and ordinary pain medications, namely. Note that it has often been argued that SMT is best for acute low back pain, not chronic, so this is right in chiropractic’s strike zone: if there is anything special, anything even remotely impressive about SMT, it should have done rather well in this contest. It should actually pretty much pull out a can of whupass on “advice and meds.” It didn’t.

SMT and standard care did equally well — or equally poorly, if you prefer. All the patients had the same experience that pretty much everyone with chronic back pain has. The researchers found that “SMT is unlikely to result in relevant early pain reduction in patients with acute low back pain.” Return to text.
For many years now I have been looking forward to getting around to writing an article all about this. Unfortunately, I have not yet made the time. Meanwhile, suffice it to say that the dominant theory of joint popping depends on the concept of “cavitation” — the rapid formation and explosive collapse of bubbles in a liquid due to pressure changes. The theory is full of holes and doesn’t begin to explain many features of joint popping, in particular the “recharge” phenomenon, wherein joints that supposedly cavitated nicely just a moment ago need to be left alone for seconds, minutes or hours before they can cavitate again. Also, the cavitation hypothesis does not explain why there is such significant variation between individuals and between joints. It is, in short, almost certainly wrong or incomplete. Return to text.
Proprioception is the sense of position and movement. See The Sixth Sense. Return to text.