Chiropractic Care: an evidence-based evaluation

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Chiropractic Care: an evidence-based evaluation

I’ve had several questions from readers about my views on chiropractic care. It’s a topic I reviewed for my evidence-based book, Alternative Medicine: The options, the claims, the evidence, how to choose wisely, that was co-published and endorsed by the Christian Medical and Dental Associations (CMDA) as “medically reliable and biblically sound.”

Here’s an excerpt from our chapter on chiropractic care:
What It Is
Daniel David Palmer, the founder of chiropractic care, was a self-taught healer at a time — the 1890s — when science had yet to have a serious impact on medicine. The country doctor rode his horse and buggy from home to home, giving patients more loving comfort than meaningful treatment. Patent medicine remained popular, most of it so filled with alcohol that heavy users could forget their discomfort as long as there was another dose in the bottle. Bayer, the German pharmaceutical com- pany, was just starting to market two products that would become well known in the twentieth century: one was aspirin, and the other was heroin!
Palmer was a grocery store owner who had learned magnetic healing and mysticism. He also had the good sense to distrust much of contemporary medicine and was determined to find a way to heal others without using drugs. Spinal manipulation for the treatment of illness had been used in one form or another for centuries. Palmer developed a series of manipulative procedures that he believed would bring health to muscles, nerves, and organs that had gotten out of alignment. He named these procedures using the Greek words cheirios and prakticos, which translate to “done by hand,” or “manipulation.” Palmer called his method “chiropractic.” Chiropractors are recognized by the D.C. after their name, which stands for Doctor of Chiropractic.
The start of chiropractic goes back to deaf janitor Harvey Lillard in Davenport, Iowa. Lillard was said to have been in good health until one day, when he was doing heavy labor, he felt something go wrong with his back. He was instantly deaf and remained that way for the next seventeen years until he encountered Palmer.
Lillard, so the story goes, had a lump on his back that Palmer determined to be a displaced vertebra. He applied pressure according to his carefully con- ceived theory, and the vertebra slipped back into place. Immediately the janitor could hear.
The frequent retelling of this story has left many details very sketchy. It is uncertain how the janitor became a patient of Palmer (he was not a doctor). Nor is it clear why he would allow the grocery store owner to manipulate his spine. What matters is that this story became the basis for Palmer’s theories, theories he claimed were proven, at least to himself, when a second patient’s heart condition was eased through similar manipulation. His techniques are now called the Palmer
Method of chiropractic
The history of chiropractic is filled with divisiveness over what problems it relieves best and precisely how manipulations bring relief. Today the Palmer concept stresses that alignment of the spine assures good health. Misalignments, called “subluxations,” interfere with the body’s natural ability to heal itself and thus need to be corrected by spinal manipulation.
Palmer used the term “subluxation” in a meta-physical way. In his view, subluxations interfered with the flow through the body of Innate Intelligence (or spark of life or spirit). This energy was therefore a form of life energy, as used in Eastern medical systems. His son, Bartlett Joshua Palmer, claimed that subluxations were the cause of all disease. This led to a split between those loyal to both Palmers and chiropractors who sought a scientific basis for chiropractic. In the view of those seeking scientific explanations, subluxations are displaced vertebrae that somehow disrupt the flow of nerve impulses through the spine. These somehow cause pain and physical illness. However, the nature, location, and very existence of subluxations remain disputed, even by chiropractors.
Chiropractors typically use X-rays and their hands to determine where manipulation is needed. One form of manipulation is done quickly, using hand thrusts involving different amounts of force. The manipulation causes adjustments that usually are accompanied by a distinctive cracking noise. Another form of manipulation involves slower, gentler movements. With both, relief may be immediate, may require a number of visits, or may come after an initial period of increased discomfort.
The claims made for chiropractic vary, depending on which approach a therapist uses. Some chiroprac- tors treat only those conditions appropriate to their training. They strive to support clinical decisions with rigorous chiropractic studies that have revealed clear benefits. Other chiropractors claim they can cure almost any disease and seek to practice as the equivalent of primary care physicians. These chiropractors point out that their training involves significant numbers of science-based courses, which they claim gives them extensive medical knowledge.
Many chiropractors also function in the capacity of naturopaths — practitioners who resist the use of medicinal drugs and surgery and emphasize nutrition and natural approaches to healing. Critics of those taking this approach point out that after one hundred years their scope of practice is not defined clearly or on a scientific basis. One such critic, William T. Jarvis, has said that those chiropractors who distance themselves from conventional medicine fail to contribute “to the worldwide body of knowledge shared by the health sciences.”
Study Findings
Hundreds of studies have been conducted, leading to more than fifty reviews of the chiropractic research. Unfortunately, many of the earlier studies had significant methodological flaws that make it difficult to use their results.
Back pain is a leading cause of pain and disability and contributes hugely to health care costs and employees missing work. Chiropractic is most frequently sought for low back pain. More than fifty randomized controlled trials of chiropractic for low back pain have been conducted. A 2003 review of this evidence found that chiropractic was superior to control therapies and therapies known to be ineffective. Chiropractic was found to be no more or no less effective than more conventional interventions such as general practitioner care, physical therapy, use of painkillers, or bed rest. Similar results were obtained, whether the low back pain was acute or chronic.
However, several studies have found that while outcomes are similar, patient satisfaction is higher with chiropractic than with conventional back care. An interesting 2005 study found preliminary evidence that improved satisfaction itself may contribute to better relief from low back pain, at least in the short term.
Another common practice in chiropractic is manipulation of the cervical spine. This is carried out to relieve neck and shoulder pain, but also headaches and migraines. Supportive evidence for treating headaches is much less convincing, with about half the studies finding benefit and half not. A 2005 review of chiropractic manipulation for acute neck pain found only one randomized study, and that had no placebo group.
There is no compelling medical evidence that chiropractic is effective for other conditions such as asthma, allergies, or painful menstrual periods. Reports are similar for cancer. We have not seen any evidence that convinces us that chiropractic is appropriate for children.
Chiropractic manipulation is not without side effects. Manipulations of the lower spine are relatively safe, but cervical manipulation around the neck is controversial. Some neck arteries are particularly prone to injury when the head and neck are suddenly rotated in unusual ways. Such injuries can trigger stroke and are sometimes fatal. Some are concerned that cervical manipulation may randomly, though rarely, cause such serious injuries. Dozens of case reports have been published identifying a connection between cervical spine manipulation and stroke. Surveys have revealed hundreds of unreported cases of suspected connections, but this is not high-quality evidence of a connection.
The lack of any consistent pattern has led to much debate over whether the injury is caused by manipulation or just happens to occur around the same time. The risk, though very low, is serious, which is even more problematic given the lack of studies supporting neck manipulation.
In general, chiropractic is relatively low in risk, although about 12 percent of patients reported mild adverse effects. While this risk is not very high if the treatment is effective, it becomes highly problematic if manipulation is done for conditions for which it has not been shown to be beneficial. This is a particular problem with certain chiropractors who place less weight on the best scientific evidence available and more weight on Palmer’s metaphysical roots.
Given such variation among chiropractors, Jarvis recommends avoiding those who:

  • appear overconfident or cultist in their zeal for chiropractic care;
  • disparage regular medicine as jealously antichiropractic;
  • criticize prescription drugs or surgery in an ideological manner;
  • attack immunization, fluoridation, pasteurization, or other public health practices;
  • X-ray all of their patients or routinely use full- spine X-rays; or
  • use scare tactics, such as claiming that the failure to undergo chiropractic care could lead to serious problems in the future.

Obviously, care should be taken in choosing one’s chiropractor.
Chiropractors differ in their scientific foundations and spiritual beliefs. Some openly promote New Age and shamanistic approaches to health and healing and disdain well-supported vaccinations and promote sales of unsupported remedies (see pp. 83–84).
Other chiropractors take a scientific approach to their profession and practice according to evidence-based guidelines.
The Christian Chiropractic Association is to be highly commended for separating New Age beliefs and practices from the scientifically based aspects of chiropractic.
Chiropractic can be a legitimate intervention, bringing welcome relief for specific muscular and skeletal conditions. Although many chiropractors claim it is also more cost-effective than conventional medicine, economic studies have found the opposite. Individual visits to chiropractors cost less, but usually more visits are recommended, and treatment is often continued for longer periods.
A New England Journal of Medicine study found that different treatment approaches for back pain were equally effective. However, primary care physicians offered the least expensive regimen, with chiropractic care being the most expensive option, costing even more than orthopedic surgery.
Treatment Categories
Conventional Medicine

  • To relieve acute and chronic low back pain (75% – 100% confidence that the therapy is potentially beneficial and the potential benefits outweigh the risks)
  • To treat some other musculoskeletal conditions (50% – 74% confidence that the therapy is potentially beneficial)


  • To relieve headaches and migraines (25% – 49% confidence that the therapy is potentially beneficial)
  • To relieve neck and shoulder pain (0% – 24% confidence that the therapy is of no benefit or potentially harmful, but the risks may outweigh the potential benefits)

Scientifically Unproven

  • To treat medical diseases or as preventive medicine (75% – 100% confidence that the therapy is of no benefit or potentially harmful)

What about chiropractic care in children? You can read my blog on the topic, “Alternative Medicine and Children – Part 2 – Chiropractic for Children” here.

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