EDITOR’S NOTE: Dr. Atwood, who would normally be scheduled to post today, is on vacation. Consequently, we are publishing the following guest post by Samuel Homola, D.C., a retired chiropractor who limited his practice to science-based methods and spoke out against the irrational and abusive practices of his colleagues. He is the author of Inside Chiropractic and Bonesetting, Chiropractic, and Cultism and co-author with Stephen Barrett of the skeptical Chirobase website, a division of Quackwatch) .

Daniel David Palmer, creator of the nebulous subluxation and father of chiropractic.

Daniel David Palmer, creator of the nebulous subluxation and father of chiropractic.

In 1895, Daniel David Palmer, a magnetic healer, announced that “95 percent of diseases are caused by displaced vertebrae; the remainder by luxations of other joints.” He opened the first chiropractic school in Davenport, Iowa—the Palmer Infirmary, which offered a three-week course of instruction.

In 1906, D.D. Palmer’s son, Bartlett Joshua Palmer, a 1902 graduate of the Palmer Infirmary, took over his father’s school. In 1924, claiming that “subluxation” of any vertebra would cause disease by compressing nerves in the intervertebral foramina, B.J. Palmer introduced the  “Neurocalometer,” a thermocouple device guaranteed to locate nerve-pinching vertebral subluxations. Chiropractors were told that if they did not use this “infallible” device to measure heat differentials on the skin over the spine, they could not competently locate and adjust a subluxation. But the Neurocalometer was not for sale. Chiropractors were forced to lease the instrument and then pay a monthly rent.

In the early 1930s, after nearly three decades of teaching that subluxations anywhere in the spine can cause disease, B.J. Palmer announced that he had found the one and only cause of disease: subluxation of the atlas. Palmer concluded that subluxation of a spinal vertebra below the axis was not possiblebecause vertebrae below that level were bound together by intervertebral discs and interlocking joints. Students at the Palmer School of Chiropractic were not permitted to adjust the spine below the axis until 1949 when full-spine techniques were once again included in the course of instruction.

B.J. Palmer’s “hole-in-one” (HIO) technique for adjusting the atlas and the axis remained popular among certain factions of the chiropractic profession. According to the 2005 edition of Job Analysis of Chiropractic, published by the National Board of Chiropractic Examines, 25.7% of practicing chiropractors include the “Palmer upper cervical/HIO” technique in their adjustive procedures.

The NUCCA club

Members of the National Upper Cervical Chiropractic Association (NUCCA) specialize in adjustment of the atlas, using the procedure as an exclusive treatment for a great variety of ailments. “The focus of the NUCCA work is the relationship between the upper cervical spine (neck) and its influence on the central nervous system and brain stem function. It is this relationship that affects every aspect of human function from the feeling sensations in your fingers to regulating hormones, controlling movement, and providing the ability to hear, see, think, and breathe.” The mission of NUCCA is defined as “Maximizing the human health potential as associated with the reduction of the Atlas Subluxation Complex (ASC).” (

With such a broad and inclusive definition, NUCCA practitioners adjust the atlas as a treatment for ailments ranging from allergies and ear infections to multiple sclerosis and epilepsy. (See here for a list of conditions treated by NUCCA practitioners.)

NUCCA procedures

In an effort to locate “minor and pain-free atlas subluxations” that allegedly cause “brainstem ischaemia” and compromise brainstem neural pathways, NUCCA practitioners commonly use these dubious procedures:

  • A supine leg-length check that reveals disparities in leg length when the head is turned left or right.
  • Use of thermography or infrared thermocouple devices to measure skin temperature over the cervical spine.
  • A postural analysis using the “NUCCA Anatometer” that requires standing on a platform apparatus that measures postural imbalance, pelvic distortion, head tilt, and unequal right and left leg weight bearing.
  • Three x-ray views of the atlas-axis area.
  • Use of a protractor to measure atlas alignment.

The patient is then placed in a side-posture position so that the heel of the hand (pisiform bone) or a machine stylus can be used to adjust the “misaligned” atlas.

NUCCA treatment of high blood pressure

The NUCCA approach to treating human ailments received unexpected support recently when a pilot study published in a legitimate medical journal suggested that correcting atlas misalignment would reduce early high blood pressure. A larger clinical study of the effect of upper cervical manipulation on Stage 1 hypertension will soon be done at the Palmer College of Chiropractic under a grant awarded by the National Center for Complementary and Alternative Medicine. “This project will replicate and expand upon a recent study published in the Journal of Human Hypertension, which found that a specific chiropractic technique known as National Upper Cervical Chiropractic Association (NUCCA) is effective in lowering high blood pressure within a small group of hypertensive patients. The study will involve eight weeks of chiropractic care in 155 patients. The clinical site for patient care will be at Palmer’s Davenport Campus.” (Chiropractic Economics, Chiropractic News, May 2008)

Views and opinions of a skeptic

I have never been convinced that manual therapy of any kind can produce a permanent reduction in blood pressure. Some forms of manual therapy can temporarily lower blood pressure while others may temporarily raise blood pressure. Tension relief or relaxation that occurs as a result of manual therapy may temporarily lower some forms of high blood pressure, but I don’t know of any way that neck manipulation can permanently reduce high blood pressure, which has many causes unrelated to the neck. Except in cases involving gross anatomical abnormality or injury to the upper cervical area, affecting vascular structures, there is no reason to believe that slight misalignment of the atlas would affect blood pressure, especially the minor, painless “subluxations” routinely adjusted by NUCCA upper cervical chiropractors

When I was in chiropractic school back in the early 1950s, I learned from Best & Taylor’s Physiological Basis of Medical Practice that compression of the carotid sinus at its bifurcation in the upper cervical area would cause a fall in blood pressure and heart rate by raising the pressure in the sinus, while pressure on the common carotid artery in the lower cervical area would raise arterial pressure and heart rate by reducing pressure within the carotid sinus. Such effects resulting from manual stimulation are, of course, temporary, and not a cure for essential hypertension or for high blood pressure caused by bad kidneys, diseased arteries, and other organic problems.

Whatever effect neck manipulation might have on blood pressure, the claim by chiropractic NUCCA “upper cervical specialists” that they can lower blood pressure by correcting minor misalignments of the atlas to relieve “brain stem ischaemia” and to normalize brainstem neural pathways is too implausible to be taken seriously. When the atlas is freely movable and is not locked by painful disease or injury, its resting place, which is determined by the anatomical structure of the articulating surfaces of the occiput, the atlas, and the axis, cannot be changed. NUCCA chiropractors may simply measure structural asymmetry to determine if the atlas is misaligned. Since there are no intervertebral discs and no interlocking joints in the articulation of the atlas with the occiput and the axis, the atlas will move when manipulated, as it does in everyday head movement, but the atlas always returns to its anatomically dictated resting place, as determined by ligamentous constraints and the contours of joint surfaces. Even when there is atlanto-occipital fixation or atlanto-axial fixation, there is no reason to believe that the brain stem would be affected if injury has not occurred and there is no anatomical deformity.

In my 43 years of practice as a chiropractor, I was never able to determine that manipulation of the spine ever permanently changed the position of the atlas or any other vertebra that is freely movable.

The NUCCA chiropractor who examined and treated the patients who participated in the study published in the Journal of Human Hypertension (Atlas vertebra realignment and achievement of arterial pressure goal in hypertensive patients: a pilot study. Vol. 21, No. 5, 2007) determined alone that he had located and corrected “atlas misalignment” in otherwise healthy patients who had misalignment as indicated by imbalances detected in a supine leg length check and by other questionable operator-dependent assessments such as measuring pelvic distortion and cervical skin temperature. A “NUCCA Anatometer” was used to measure “postural asymmetries.” The treating chiropractor, who has been using the NUCCA technique for 50 years, provided both sham procedure and real treatment in this “double blind placebo-controlled” study. He believes that the atlas vertebra is the “fuse box to the body,” and that when the atlas is misaligned as little as half a millimeter bad things happen to the body. (WebMD Medical News, March 16, 2007)

Obviously, it would be difficult or impossible for a dedicated non-blinded NUCCA practitioner to provide sham intervention to one group and real treatment to another group without transmitting his belief to the patient, possibly triggering a placebo effect in the treatment group.  X-ray measurements performed by one person might be influenced by patient positioning and by the prejudice of the investigator. An attempt to replicate the findings of such a flawed pilot study with another study done in a chiropractic college using similar procedures would certainly raise questions. Short term treatment for fluctuating blood pressures in patients with Stage 1 hypertension (pressures less than 159/99 mm of Hg, with no known cause) would be difficult to evaluate.  The conclusion that “restoration of Atlas alignment is associated with marked and sustained reductions in BP” after eight weeks of weekly upper neck manipulation begs for another explanation.

Examining claims that chiropractic manipulation can lower blood pressure, a study published in a 2002 issue of Journal of Hypertension (Treatment of Hypertension with Alternative Therapies Study: a randomized clinical trial. Vol. 29, No. 10) concluded that “For patients with high normal blood pressure or Stage 1 hypertension, chiropractic spinal manipulation in conjunction with a dietary modification program offered no advantage in lowering either diastolic or systolic blood pressure compared to diet alone.”

The minor atlas subluxations routinely found by NUCCA chiropractors have not been proven to be significant. I would be surprised if a legitimate properly controlled study offered proof that upper neck manipulation would permanently lower blood pressure that has an organic origin. The claim by NUCCA practitioners that a painless slightly misaligned atlas is a cause of high blood pressure does not have enough supporting evidence to warrant the risk of manipulating the necks of patients suffering from high blood pressure, risking injury to vertebrobasilar arteries.

The findings of the questionable and controversial study in the Journal of Human Hypertension, offering support for contentions that correcting a minor atlas misalignment will lower blood pressure, are being extrapolated by NUCCA chiropractors to prove that upper cervical chiropractic is an effective treatment for organic ailments. According to the chiropractor who participated in the blood pressure study, “…high blood pressure is far from the only thing an Atlas misalignment causes.” (WebMD Medical News, March 16, 2007)

Although the NUCCA blood pressure study did note that “The mechanism as to why this improvement in BP occurs is unknown and cannot be determined by this study,” the study itself reads like a chiropractic promotional piece. For example, the study states that “What is clear is that misalignment of the Atlas vertebra can be determined by assessment of the alignment of the pelvic crests,” adding that “…pain was not present in any of the patients randomized in this study.” Such statements may be used by chiropractors to support treatment of a variety of human ailments, based on measurement of common but insignificant vertebral misalignment or on harmless structural deviations from normal.



  • 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.