Kinesiology is the scientific study of movement. Applied kinesiology (AK) is a bogus muscle-testing technique most commonly used by chiropractors but also by some others. It is neither scientific nor valid. It’s based on a delusion. One commenter said, “It is denounced as an absurd and dishonest parlour trick by anyone else who knows anything about it.”[i]
AK was originated by a chiropractor, George J. Goodheart, in 1964. He claimed that AK muscle testing could be used to evaluate[ii] nerve, vascular, and lymphatic systems; the body’s nutritional state; the flow of “energy” along “acupuncture meridians”; and “cerebro spinal fluid function.” There is no evidence for any of this.
Weaker muscle responses supposedly indicate illness in a corresponding body organ, or an allergy, or a nutritional deficiency. Numerous double-blind studies have evaluated AK and found it to be no better than chance guessing.
A 2013 double-blinded randomized study assessed the validity of AK [iii]by comparing the muscle strength of 51 subjects when holding test tubes containing saline to muscle strength when holding a solution of a toxin. Muscle strength was determined by subjective manual testing by two different AK practitioners and by the objective measurements of a dynamometer. It found that the results reported by the AK practitioners were no better than chance, and neither were the results of the dynamometer. It concluded that AK testing was unreliable and not replicable by different examiners, and there was no evidence that it worked any better than chance. They found that belief in AK did not influence results. They also reviewed the published literature and commented:
“The research published by the Applied Kinesiology field itself is not to be relied upon, and in the experimental studies that do meet accepted standards of science, Applied Kinesiology has not demonstrated that it is a useful or reliable diagnostic tool upon which health decisions can be based.”
Even integrative medicine guru Dr. Weil disapproves. His website[iv] says, “Dr. Weil believes that not even the best of applied kinesiology tests and diagnostic procedures has stood up to studies comparing them with standard medical techniques, and is unaware of any sound scientific evidence to support the claims made by AK practitioners.”
Many practitioners claim that AK can be used to diagnose allergies. I once attended a lecture by a chiropractor who swore by it. He would have the patient hold a sealed glass vial containing an allergen and would compare the muscle resistance in their arm when holding and not holding the vial. He found all manner of “allergies.” He described one patient he thought must be allergic to something in the workplace. He said, “I didn’t have a vial of Boeing, but I had him think about Boeing and that worked just as well.” He described all kinds of success stories with food allergies. He would have the patient avoid the offending food for a time; their symptoms would improve, and then they could start eating that food again. In describing how he became a chiropractor, he happened to mention that he had never been very good at science in school; that was the one thing in his lecture that I could believe.
Nambudripad’s Allergy Elimination Techniques (NAET)
He was practicing Nambudripad’s Allergy Elimination Techniques (NAET). Dr. Nambudripad was a student chiropractor and acupuncturist when she developed NAET. She blamed ADHD, ADD, autism, and migraine headaches on allergies and explained that allergies are caused by “repulsive electromagnetic fields between an individual and the object (allergen).” She claimed 95% of human ailments are caused by allergies to substances, emotions, or even colors. She claimed she could remove these blockages with acupressure or acupuncture. Her claims are pseudoscientific and have been debunked on Quackwatch[v] and by numerous professional allergy associations.
Acceptance by chiropractors
Despite the lack of evidence, AK is widely accepted by chiropractors and some other practitioners. A 2003 survey by the National Board of Chiropractic Examiners showed that AK was the 10th most frequently used chiropractic technique and was used by 37.6% of chiropractors. In a subsequent survey in 2009, they didn’t even ask about the use of AK or any of the subluxation-based “adjustive procedures” that might place chiropractic in an unfavorable light. There are no up-to-date statistics, but it is common knowledge that quite a few chiropractors still use AK.
One of my favorite skeptical stories involves AK. You can read about it in Ray Hyman’s article on ideomotor action[vi] on the Quackwatch website. A group of chiropractors agreed to a test in Dr. Wallace Sampson’s medical office. First, they demonstrated that they could distinguish between “good” sugar (glucose) and “bad” sugar (fructose) by putting a drop of sugar solution on the subject’s tongue and pushing their upraised arm down to a horizontal position. The chiropractors were able to reliably tell whether it was glucose or fructose based on how strongly the subject could resist the chiropractor’s pressure on their arm. Then they were re-tested under strict double-blind procedures with coded test tubes; no one in the room knew which sugar was in which test tube. Under those conditions, the chiropractors failed miserably; they couldn’t tell the sugars apart. But they still thought they could; never mind evidence and reality. The head chiropractor told Ray “You see, that is why we never do double-blind testing anymore. It never works!” At first Ray thought he was joking, but he wasn’t. The chiropractor was absolutely convinced that AK was valid; and if the test indicated otherwise, that could only mean that the scientific method was somehow defective. Belief can be stronger than reality.
Delusions based on the ideomotor effect
In that same Quackwatch article, Ray Hyman explains how the ideomotor effect can fool chiropractors and scientists. Expectations translate into almost undetectable motor movements. Since the operator is not consciously aware that he moved, he attributes the movement to an external force, often one unknown to science. This can translate to delusions of grandeur or of persecution. Psychological forces come into play, allowing proponents to protect their beliefs by distorting, forgetting, or ignoring evidence.
AK practitioners think they are applying the same amount of force every time. But their belief systems fool them into subconsciously using less or more force. The patients believe they are consistently using the same amount of resistance, but if they know what to expect, they can subconsciously adjust their resistance. And there are parlor tricks that practitioners may use consciously or unconsciously, pressing down on slightly different sites on the arm or applying pressure at a slightly different angle. As Ray Hyman puts it “Knowing an allegedly harmful substance has been applied, the practitioner unconsciously presses a little harder and the patient unconsciously resists a bit less.”
It gets sillier and sillier. There is a picture on the Internet where a chiropractor is evaluating a child by testing the mother’s arm strength with the mother lying down while the child sits on her. And I heard about a layman who claimed to use AK to test people over the telephone and advise them about what supplements they should take.
Richard Feynman reminded us that the first principle of science is not to fool yourself – and you are the easiest person to fool. The only reliable way to keep from fooling ourselves is to rely on proper scientific testing with a control group.
The International College of Applied Kinesiology- USA (ICAK-USA)
AK even has its own professional organization, the International College of Applied Kinesiology- USA (ICAK-USA). When Stephen Barrett called AK “phony,” on Quackwatch,[vii] they protested and asked him to publish their rebuttal letter, which he did.[viii] It is far from convincing. It essentially says that AK was never intended to be used alone, and the negative studies were from people who weren’t doing true AK (this is the “no true Scotsman” logical fallacy). They claimed to have research on their website showing that AK was effective when properly used, but the page listing those studies no longer exists, if it ever did.
Other chiropractic delusions
The history of chiropractic is riddled with delusions. Its founder, D.D. Palmer, erroneously thought he could detect bones out of place in the spine and put them back, and he thought he had cured a deaf man by manipulating his back (although the man’s daughter later claimed he remained deaf until the day he died). Palmer’s son BJ imagined that he could feel the course of nerves under the skin with his fingers; his “nerve tracing” technique was taught for years before it was discarded.
True medical subluxations are partial dislocations of a joint that can be seen on x-rays; the chiropractic subluxation is a myth. To this day, many chiropractors have continued to diagnose “chiropractic subluxations.” They are inconsistent: different chiropractors disagree about which vertebra is subluxed. Once x-ray evidence had demonstrated the reality that there are not actually any bones out of place; they revised the definition of chiropractic subluxation, calling it “a complex of functional and/or structural and or pathological articular changes that compromise neural integrity and may influence organ system and general health.” In my opinion, that is so vague it amounts to an excuse for chiropractors to adjust the spines of anyone they want to treat.
Some chiropractors today reject the subluxation concept. In 2009, chiropractors reviewed the literature and published an article in the journal Chiropractic and Osteopathy.[ix] They found no evidence that the chiropractic subluxation was associated with any disease process or that it created any suboptimal health conditions. They concluded that “the subluxation construct has no valid clinical applicability.”
In 2010, the General Chiropractic Council of the UK offered this guidance to chiropractors: “The chiropractic vertebral subluxation complex is an historical concept but it remains a theoretical model. It is not supported by any clinical research evidence that would allow claims to be made that it is the cause of disease or health concerns.”
Some chiropractors continue to practice upper cervical chiropractic in the belief that adjusting the top cervical vertebra will correct subluxations throughout the spine. A clearly delusional chiropractor was a woman who thought she was practicing upper cervical chiropractic but was not actually touching the patient. When confronted with a video of her performance, she said, “My whole thing is that I’m touching.”[x] I still don’t know whether to laugh or cry.
The National Board of Chiropractic Examiner study mentioned above also showed that 41% of chiropractors used acupressure or meridian therapy, 39% used homeopathy, and 13% used acupuncture with needles. And it revealed that many chiropractors treat conditions they have no business treating, such as diabetes, cancer, heart attacks, and infantile colic.[xi]
AK is bogus, but it serves to illustrate the fallibility of human beliefs and the need for controlled scientific studies.
This article was originally published as a “Reality Is the Best Medicine” column in Skeptical Inquirer