I spent 43 years in private practice as a “science-based” chiropractor and a critic of the chiropractic vertebral subluxation theory. I am often asked how I justified practicing as a chiropractor while renouncing the basic tenets of chiropractic. My answer has always been: I was able to offer manipulation in combination with physical therapy modalities as a treatment for mechanical-type back pain—a service that was not readily available in physiotherapy or in any other sub-specialty of medicine.

If I had it to do over again, however, I would study physical therapy rather than chiropractic. Considering the controversy that continues to surround the practice of chiropractic, I would not recommend that anyone spend the time, effort, and money required to earn a degree in chiropractic. Physical therapy, which is now beginning to include spinal manipulation in its treatment armamentarium, may offer better opportunity for those interested in manual therapy. Properly-limited, science-based chiropractors are now essentially competing with physical therapists who use manual therapy. Unfortunately, only a few chiropractors have renounced the vertebral subluxation theory, making it difficult to find a “good chiropractor.” I consider physical therapy to be more progressive and more evidence based. For this reason, I generally recommend the manipulative services of a physical therapist rather than a chiropractor.

There are some science-based chiropractors who use manipulation appropriately, but until the chiropractic profession abandons the implausible vertebral subluxation theory and is defined according to standards dictated by anatomy, physiology, and neurology, I would not describe it as a science-based profession.

Heretics and science-based chiropractors

After my second year in chiropractic college, I came to the conclusion that the chiropractic subluxation theory was not a credible construct. In an effort to separate the good from the bad in the use of manipulation by chiropractors, I published my book Bonesetting, Chiropractic, and Cultism in 1963, renouncing the chiropractic vertebral subluxation theory and suggesting that chiropractors should limit their use of spinal manipulation to treatment of back pain. Over the years, I wrote many articles critical of chiropractic, always suggesting that the definition of chiropractic be changed in chiropractic colleges and state laws so that the next generation of chiropractors would be properly limited. Science-based chiropractors could be separated from their subluxation-based counterparts under a new degree, such as a “Doctor of Chiropractic Therapy” (DCT) or a “Chiropractic Manual Therapist” (CMT). I suggested that it would not be necessary for chiropractors to practice as “doctors”—they could practice as therapists offering non-surgical, drug-free treatment for back pain and related musculoskeletal problems, a new specialty combining use of manipulation with physical therapy modalities. Needless to say, this change never occurred and I was labeled a “chiropractic heretic”—or worse—by my colleagues.

Today, the educational requirements for obtaining a degree in chiropractic have improved. Most chiropractic college applicants now have undergraduate degrees. But the basic definition of chiropractic has not changed. As currently defined by the North American Association of Chiropractic Colleges, “Chiropractic is concerned with the preservation and restoration of health, and focuses particular attention on the subluxation,” indicating that the majority of chiropractors may still adhere to a basic version of the subluxation theory. Few chiropractic college graduates may be able or willing to abandon a belief system they must depend upon for an income.

Filling a need for manual therapy

At the present time, spinal manipulation is still not as readily available in medical practice as it should be, leaving an opening for the services of a good─albeit rare─science-based chiropractor who combines manipulation with physical therapy modalities. But it would be necessary for such a chiropractor to openly renounce the chiropractic vertebral subluxation theory (more of a belief than a theory) and publicly state that his or her practice is limited to care of musculoskeletal problems. Unfortunately, as indicated by the paradigm of the North American Association of Chiropractic Colleges, such chiropractors may be in the minority, even among recent graduates─at least in the United States.

High-velocity, low-amplitude (thrust type) spinal manipulation is not yet commonly used by physical therapists. For this reason, orthopedists and neurologists who are familiar with manual medicine are often willing to refer back-pain patients to a good chiropractor for manipulation as well as to steer patients away from subluxation-based chiropractors. Physicians can often locate good chiropractors by reading their office notes and by talking with their patients.

Most cases of back pain are self limiting, and spinal manipulation is not often more effective than other physical treatment modalities in affecting the final outcome. But in many cases, appropriate spinal manipulation may provide more immediate symptomatic relief than other forms of therapy. And in special cases, thrust-type manipulation may be the best way to restore mobility in spines stiffened by post-traumatic adhesions or locked by muscle spasm and binding vertebral joints. For this reason, benefit may outweigh risk when manipulation is used appropriately in the treatment of carefully selected cases of mechanical-type back pain. But there is no evidence to indicate that upper neck manipulation provides more benefit than risk, considering the risk of damage to vertebrobasilar arteries.

Use of manipulation combined with instruction, massage, physical therapy, and rehabilitation may be the best way to relieve mechanical back pain and keep the patient mobile until recovery is complete—provided, of course, that treatment is based on a correct diagnosis. A science-based chiropractor who works in concert with a patient’s physician can often provide such a treatment regimen—as opposed to solo subluxation-based chiropractors whose primary concerns are locating and correcting vertebral subluxations.

Separating the good from the bad

Since the vertebral subluxation theory continues to form the foundation of chiropractic, it seems unlikely that the chiropractic profession will ever abandon the belief that adjusting spinal joints will restore and maintain health. Many chiropractors who say that they reject D.D. Palmer’s subluxation theory simply come up with new terminology that identifies some kind of vertebral joint “dysfunction” that allegedly affects the nervous system, thus interfering with the body’s ability to heal itself. Failure of chiropractic colleges to reject such views and make the changes needed to develop chiropractic into a musculoskeletal back-pain specialty (with commensurate changes in state laws) may simply allow chiropractic to continue as an alternative healing method, such as homeopathy or acupuncture, permitting its practitioners to treat the gamut of human ailments as “primary care providers.” It may then be necessary to depend primarily upon physical therapists for appropriate use of manipulation based on credible research. Chiropractors who can no longer tolerate the controversy associated with chiropractic can retrain as physical therapists, making good use of their training in the use of manipulation. Forty-three states now grant physical therapists direct access to patients; that is, referral from a physician is not needed.

Although I am a critic of chiropractic, I would not hesitate to offer support to a good science-based chiropractor who has separated himself or herself from the herd by expressing views that oppose the implausible treatment methods that are so prevalent among chiropractors. When I was in practice as a chiropractor, I felt an obligation to speak out so that friends, patients, and health-care professionals would not assume that my approach represented chiropractic in general. I worried that a patient who was pleased with my services might assume that treatment by any other chiropractor would be the same. Unfortunately, chiropractic treatment based on the implausible vertebral subluxation theory may be so inconsistent that treatment for any condition may range from an atlas adjustment to a sacral adjustment, all purported to be effective in improving health by removing “nerve interference.” So far, apparently reluctant to bite the hand that feeds them, chiropractic associations in the United States have failed to publicly renounce the vertebral subluxation theory or to condemn the multitude of dubious treatment methods based on subluxation theory.

Today, chiropractic treatment in America is like Forrest Gump’s box of chocolates: “You never know what you’re gonna get.”

Why the chiropractic vertebral subluxation theory is implausible

Scientific consensus does not support the theory that nerve interference caused by vertebral misalignment is a cause of organic disease. Spinal nerves primarily supply musculoskeletal structures. Organ function is governed by the autonomic nervous system in concert with psychic, chemical, hormonal, and circulatory factors.

The vagus nerve is an autonomic (parasympathetic) cranial nerve that originates in the brain stem and passes down through the neck and thorax to the abdomen to supply organs along its path. Preganglionic autonomic fibers, which pass through spinal segments from T1 thru L2, terminate in sympathetic trunk and splanchnic ganglia located outside the spinal column. Autonomic cranial and sacral nerves pass through solid bony openings.

The vagus nerve along with autonomic ganglia and nerve plexuses provide overlapping sympathetic and parasympathetic nerve supply from many directions to assure continued function of the body’s organs, independent of spinal nerves. This is why a transverse spinal cord injury at the C4 or C5 level can paralyze musculoskeletal structures from the neck down while involuntary functions of organs continue. With this fail-safe mechanism in place, I don’t know of any reason to believe that slight misalignment of a single vertebra or an undetectable “vertebral subluxation complex” can be a cause of organic disease as suggested by the chiropractic vertebral subluxation theory.

Spinal nerves are commonly compressed by bony spurs and herniated discs. Even the most severe compression of a spinal nerve, which may cripple the supplied musculoskeletal structures, does not cause organic disease. The sphincter muscles involved in voluntary control of bladder and bowel functions are supplied primarily by spinal nerves and sympathetic fibers that are well protected in their passage through the solid bony openings that form the sacral foramina.

When there is disc protrusion into the spinal canal, or when there is a space-occupying mass in the spinal canal compressing cauda equina spinal nerves that travel down (from the conus medullaris at the lower border of the 2nd lumbar vertebra where the spinal cord ends) to exit lumbar and sacral foramina, loss of voluntary control of bladder and bowel muscles (most commonly urinary retention) signals a medical emergency that requires the immediate attention of a neurosurgeon.

Implausible theory fosters implausible treatment methods

The implausibility of the chiropractic vertebral subluxation theory does not provide a foundation for a consistent, replicable treatment method. As a result, vertebral subluxation theory has fostered the development of a great variety of antithetical chiropractic treatment methods designed to “remove nerve interference,” many of which do not involve use of hands-on manipulation—such as healing touch or use of a spring-loaded stylus to tap vertebrae into alignment. Such treatment methods are unrelated to legitimate use of manual manipulation in the treatment of back pain and related musculoskeletal problems.

The chiropractic (undetectable) “vertebral subluxation complex” is not the same as a true vertebral misalignment, a true vertebral subluxation, or any one of a number of joint problems that cause mechanical-type symptoms (which can often be relieved by manipulating the spine) but are not alleged to be a cause of visceral disease.

Proper treatment hinges on a proper diagnosis, which, in my opinion, is never a “vertebral subluxation complex.”


  • Samuel Homola is a retired chiropractor who has been expressing his views about the benefits of appropriate use of spinal manipulation (as opposed to use of such treatment based on chiropractic subluxation theory) since publication of his book Bonesetting, Chiropractic, and Cultism in 1963. He retired from private practice in 1998. His 15 published books include Inside Chiropractic, published by Prometheus Books in 1999.

Posted by Sam Homola

Samuel Homola is a retired chiropractor who has been expressing his views about the benefits of appropriate use of spinal manipulation (as opposed to use of such treatment based on chiropractic subluxation theory) since publication of his book Bonesetting, Chiropractic, and Cultism in 1963. He retired from private practice in 1998. His 15 published books include Inside Chiropractic, published by Prometheus Books in 1999.