Chiropractic Manipulation
Intervention
A Doctor of Chiropractic (DC) performs spinal manipulative therapy
ICD-10-PCS	9
MeSH	D026882

Alternative medical systems

Acupuncture · Anthroposophic medicine · Herbalism · Homeopathy · Naturopathy · Orthopathy · Osteopathy/Chiropractic
Traditional medicine
Chinese · Mongolian · Tibetan · Unani · Siddha · Ayurveda
NCCAM classifications
Whole medical systems · Mind-body interventions · Biologically based therapies · Manipulative therapy · Energy therapies
See also
Alternative medicine · Glossary · People
v t e

Chiropractic is a health care profession concerned with the diagnosis, treatment and prevention of disorders of the neuromusculoskeletal system and the effects of these disorders on general health.^[1] It is generally categorized as complementary and alternative medicine (CAM).^[2] Although chiropractors have many attributes of primary care providers, chiropractic has more of the attributes of a medical specialty like dentistry or podiatry.^[3]

The main chiropractic treatment technique involves manual therapy, including manipulation of the spine, other joints, and soft tissues; treatment also includes exercises and health and lifestyle counseling.^[4] Traditional chiropractic assumes that a vertebral subluxation interferes with the body's innate intelligence,^[5] a vitalistic notion ridiculed by the scientific and healthcare communities.^[6] A large number of chiropractors want to separate themselves from the traditional vitalistic concept of innate intelligence.^[7]

D.D. Palmer founded chiropractic in the 1890s, and his son B.J. Palmer helped to expand it in the early 20th century.^[8] It has two main groups: "straights", now the minority, emphasize vitalism, innate intelligence and spinal adjustments, and consider vertebral subluxations to be the cause of all disease; "mixers", the majority, are more open to mainstream views and conventional medical techniques, such as exercise, massage, and ice therapy.^[7]

Chiropractic is well established in the U.S., Canada and Australia^[9] and is the "third largest of the doctored health professions (behind only medicine and dentistry)".^[10] It overlaps with other manual-therapy professions, including massage therapy, osteopathy, and physical therapy.^[11] Most who seek chiropractic care do so for low back pain.^[12]

Throughout its history, chiropractic has been controversial.^[13][14] For most of its existence it has battled with mainstream medicine, sustained by pseudoscientific ideas such as subluxation and innate intelligence^[15] that are not based on solid science.^[16] Despite the consensus of public health professionals regarding the benefits of vaccination, among chiropractors there are significant disagreements over the subject,^[17] which has led to negative impacts on both public vaccination and mainstream acceptance of chiropractic.^[18] The American Medical Association called chiropractic an "unscientific cult"^[19] and boycotted it until losing an antitrust case in 1987.^[20] Chiropractic has developed a strong political base and sustained demand for services; in recent decades, it has gained more legitimacy and greater acceptance among medical physicians and health plans in the U.S.,^[20] and the principles of evidence-based medicine have been used to review research studies and generate practice guidelines.^[21]

Many studies of treatments used by chiropractors have been conducted, often with conflicting results.^[16][22] Manual therapies commonly used by chiropractors are effective for the treatment of low back pain,^[23][24] and might also be effective for the treatment of lumbar disc herniation with radiculopathy,^[25][26] neck pain,^[27] some forms of headache,^[28][29] and some extremity joint conditions.^[30][31] The efficacy and cost-effectiveness of maintenance chiropractic care are unknown.^[32]

Chiropractic care is generally safe when employed skillfully and appropriately.^[1] Spinal manipulation is frequently associated with mild to moderate adverse effects, with serious or fatal complications in rare cases.^[33][34] A systematic review found that the risk of death from manipulations to the neck outweighs the benefits.^[35]

Philosophy[link]

Chiropractic's early philosophy was rooted in vitalism, spiritual inspiration and rationalism. A philosophy based on deduction from irrefutable doctrine helped distinguish chiropractic from medicine, provided it with legal and political defenses against claims of practicing medicine without a license, and allowed chiropractors to establish themselves as an autonomous profession. This "straight" philosophy, taught to generations of chiropractors, rejects the inferential reasoning of the scientific method,^[37] and relies on deductions from vitalistic first principles rather than on the materialism of science.^[36]

However, most practitioners currently accept the importance of scientific research into chiropractic,^[37] and most practitioners are "mixers" who attempt to combine the materialistic reductionism of science with the metaphysics of their predecessors and with the holistic paradigm of wellness;^[36] a 2008 commentary proposed that chiropractic actively divorce itself from the straight philosophy as part of a campaign to eliminate untestable dogma and engage in critical thinking and evidence-based research.^[38]

Although a wide diversity of ideas currently exists among chiropractors,^[37] they share the belief that the spine and health are related in a fundamental way, and that this relationship is mediated through the nervous system.^[39] Chiropractors examine the biomechanics, structure and function of the spine, along with its effects on the musculoskeletal and nervous systems and what they believe to be its role in health and disease.^[40]

Chiropractic philosophy includes the following perspectives:^[36]

• Holism assumes that health is affected by everything in an individual's environment; some sources also include a spiritual or existential dimension.^[41] In contrast, reductionism in chiropractic reduces causes and cures of health problems to a single factor, vertebral subluxation.^[38]
• Conservatism considers the risks of clinical interventions when balancing them against their benefits. It emphasizes noninvasive treatment to minimize risk, and avoids surgery and medication.^[40]
• Homeostasis emphasizes the body's inherent self-healing abilities. Chiropractic's early notion of innate intelligence can be thought of as a metaphor for homeostasis.^[37]
• Straights tend to use an approach that focuses on the chiropractor's perspective and the treatment model, whereas mixers tend to focus on the patient and the patient's situation.^[36]

Straights and mixers[link]

Chiropractic is often described as two professions masquerading as one. Unlike the distinction between podiatry (a science-based profession for foot disorders) and foot reflexology (an unscientific philosophy which posits that many disorders arise from the feet), in chiropractic the two professions attempt to live under one roof,^[38] albeit with much tension between them.^[42]

Straight chiropractors adhere to the philosophical principles set forth by D.D. and B.J. Palmer, and retain metaphysical definitions and vitalistic qualities. Straight chiropractors believe that vertebral subluxation leads to interference with an "innate intelligence" exerted via the human nervous system and is a primary underlying risk factor for many diseases. Straights view the medical diagnosis of patient complaints (which they consider to be the "secondary effects" of subluxations) to be unnecessary for chiropractic treatment. Thus, straight chiropractors are concerned primarily with the detection and correction of vertebral subluxation via adjustment and do not "mix" other types of therapies into their practice style.^[43]

Their philosophy and explanations are metaphysical in nature and they prefer to use traditional chiropractic lexicon terminology (i.e. perform spinal analysis, detect subluxation, correct with adjustment, etc.). They prefer to remain separate and distinct from mainstream health care. Although considered the minority group, "they have been able to transform their status as purists and heirs of the lineage into influence dramatically out of proportion to their numbers."^[7]

Mixer chiropractors "mix" diagnostic and treatment approaches from osteopathic, medical, and chiropractic viewpoints. Unlike straight chiropractors, mixers believe subluxation is one of many causes of disease, and they incorporate mainstream medical diagnostics and employ many treatments including conventional techniques of physical therapy such as exercise, massage, ice packs, and moist heat, along with nutritional supplements, acupuncture, homeopathy, herbal remedies, and biofeedback. Mixers tend to be open to mainstream medicine and are the majority group.^[7]

Although mixers are the majority group, many of them retain some belief in vertebral subluxation as shown in a 2003 survey of 1100 North American chiropractors, which found that 88% wanted to retain the term "vertebral subluxation complex", and that when asked to estimate the percent of disorders of internal organs (such as the heart, the lungs, or the stomach) that subluxation significantly contributes to, the mean response was 62%.^[44] Despite this finding, a 2008 survey of 6000 American chiropractors demonstrated that most chiropractors seem to believe that a subluxation-based clinical approach may be of limited utility for addressing visceral disorders, and greatly favored non-subluxation-based clinical approaches for such conditions.^[45][46]

Vertebral subluxation[link]

Palmer hypothesized that vertebral joint misalignments, which he termed vertebral subluxations, interfered with the body's function and its inborn (innate) ability to heal itself.^[5] D.D. Palmer repudiated his earlier theory that vertebral subluxations caused pinched nerves in the intervertebral spaces in favor of subluxations causing altered nerve vibration, either too tense or too slack, affecting the tone (health) of the end organ. D.D. Palmer, using a vitalistic approach, imbued the term subluxation with a metaphysical and philosophical meaning. He qualified this by noting that knowledge of innate intelligence was not essential to the competent practice of chiropractic.^[47] This concept was later expanded upon by his son, B.J. Palmer and was instrumental in providing the legal basis of differentiating chiropractic medicine from conventional medicine. In 1910, D.D. Palmer theorized that the nervous system controlled health:

"Physiologists divide nerve-fibers, which form the nerves, into two classes, afferent and efferent. Impressions are made on the peripheral afferent fiber-endings; these create sensations that are transmitted to the center of the nervous system. Efferent nerve-fibers carry impulses out from the center to their endings. Most of these go to muscles and are therefore called motor impulses; some are secretory and enter glands; a portion are inhibitory, their function being to restrain secretion. Thus, nerves carry impulses outward and sensations inward. The activity of these nerves, or rather their fibers, may become excited or allayed by impingement, the result being a modification of functionality—too much or not enough action—which is disease."^[48]

Vertebral subluxation, a core concept of traditional chiropractic, remains unsubstantiated and largely untested, and a debate about whether to keep it in the chiropractic paradigm has been ongoing for decades.^[6] In general, critics of traditional subluxation-based chiropractic (including chiropractors) are skeptical of its clinical value, dogmatic beliefs and metaphysical approach. While straight chiropractic still retains the traditional vitalistic construct espoused by the founders, evidence-based chiropractic suggests that a mechanistic view will allow chiropractic care to become integrated into the wider health care community.^[6] This is still a continuing source of debate within the chiropractic profession as well, with some schools of chiropractic still teaching the traditional/straight subluxation-based chiropractic, while others have moved towards an evidence-based chiropractic that rejects metaphysical foundings and limits itself to primarily neuromusculoskeletal conditions.^[49][50]

A 2003 survey of North American chiropractors found that 88% wanted to retain the term vertebral subluxation complex, and that when asked to estimate the percent of disorders of internal organs (such as the heart, the lungs, or the stomach) that subluxation significantly contributes to, the mean response was 62%.^[44] In 2005, the chiropractic subluxation was defined by the World Health Organization as "a lesion or dysfunction in a joint or motion segment in which alignment, movement integrity and/or physiological function are altered, although contact between joint surfaces remains intact. It is essentially a functional entity, which may influence biomechanical and neural integrity." This differs from the medical definition of subluxation as a significant structural displacement, which can be seen with static imaging techniques such as X-rays.^[1]

The 2008 book Trick or Treatment states "X-rays can reveal neither the subluxations nor the innate intelligence associated with chiropractic philosophy, because they do not exist."^[51] Attorney David Chapman-Smith, Secretary-General of the World Federation of Chiropractic, has stated that "Medical critics have asked how there can be a subluxation if it cannot be seen on x-ray. The answer is that the chiropractic subluxation is essentially a functional entity, not structural, and is therefore no more visible on static x-ray than a limp or headache or any other functional problem."^[52] The General Chiropractic Council, the statutory regulatory body for chiropractors in the United Kingdom, states that the chiropractic vertebral subluxation complex "is not supported by any clinical research evidence that would allow claims to be made that it is the cause of disease."^[53]

Scope of practice[link]

Therapeutic chairs at a chiropractic office in New Jersey.

Chiropractors, also known as doctors of chiropractic or chiropractic physicians^[54] in many jurisdictions,^[55] emphasize the conservative management of the neuromusculoskeletal system without the use of medicines or surgery,^[1] with special emphasis on the spine.^[56] Chiropractic combines aspects from mainstream and alternative medicine, and there is no agreement about how to define the profession: although chiropractors have many attributes of primary care providers, chiropractic has more of the attributes of a medical specialty like dentistry or podiatry.^[3]

It has been proposed that chiropractors specialize in nonsurgical spine care, instead of attempting to also treat other problems,^[3][38] but the more expansive view of chiropractic is still widespread.^[57] Mainstream health care and governmental organizations such as the World Health Organization consider chiropractic to be complementary and alternative medicine (CAM).^[2]

A 2008 study reported that 31% of surveyed chiropractors categorized chiropractic as CAM, 27% as integrated medicine, and 12% as mainstream medicine.^[58] Aligning with conventional medicine could give chiropractors more university affiliation and access to hospitals and long-term facilities; aligning with the CAM movement could bring more patients looking for nonmedical approaches.^[59]

Chiropractors use x-ray radiography to examine the bone structure of a patient.

The practice of chiropractic medicine involves a range of diagnostic methods including skeletal imaging, observational and tactile assessments, and orthopedic and neurological evaluation.^[1] A chiropractor may also refer a patient to an appropriate specialist, or co-manage with another health care provider.^[3] Common patient management involves spinal manipulation (SM) and other manual therapies to the joints and soft tissues, rehabilitative exercises, health promotion, electrical modalities, complementary procedures, and lifestyle counseling.^[4]

Chiropractors are not licensed to write medical prescriptions or perform major surgery in the U.S.,^[60] but that recently changed when New Mexico became the first state to allow "advanced practice" trained chiropractors the ability to prescribe certain medications.^[61][62] Their scope of practice varies by state, based on inconsistent views of chiropractic care: some states, such as Iowa, broadly allow treatment of "human ailments"; some, such as Delaware, use vague concepts such as "transition of nerve energy" to define scope of practice; others, such as New Jersey, specify a severely narrowed scope.^[63]

States also differ over whether chiropractors may conduct laboratory tests or diagnostic procedures, dispense dietary supplements, or use other therapies such as homeopathy and acupuncture; in Oregon they can become certified to perform minor surgery and to deliver children via natural childbirth.^[60] A 2003 survey of North American chiropractors found that a slight majority favored allowing them to write prescriptions for over-the-counter drugs.^[44]

A 2010 survey found 72% of Switzerland chiropractors judged the current allowance in Switzerland to prescribing nonprescription medication as an advantage for chiropractic treatment.^[64] A related field, veterinary chiropractic, applies manual therapies to animals and is recognized in a few U.S. states,^[65] but is not recognized by the American Chiropractic Association as being chiropractic.^[66]

A treatment table at a chiropractic office.

Chiropractic overlaps with several other manual-therapy professions, including massage therapy, osteopathy, physical therapy, and sports medicine.^[11][67] Chiropractic is autonomous and competitive with mainstream medicine,^[68] and osteopathy outside the U.S. remains primarily a manual medical system;^[69] physical therapists work alongside and cooperate with mainstream medicine, and osteopathic medicine in the U.S. has merged with the medical profession.^[68] Members distinguish these competing professions with rhetorical strategies that include claims that, compared to other professions, chiropractors heavily emphasize spinal manipulation, tend to use firmer manipulative techniques, and promote maintenance care; that osteopaths use a wider variety of treatment procedures; and that physical therapists emphasize machinery and exercise.^[11]

Treatment techniques[link]

Spinal manipulation, which chiropractors call "spinal adjustment" or "chiropractic adjustment", is the most common treatment used in chiropractic care.^[70] Spinal manipulation is a passive manual maneuver during which a three-joint complex is taken past the normal range of movement, but not so far as to dislocate or damage the joint. Its defining factor is a dynamic thrust, which is a sudden force that causes an audible release and attempts to increase a joint's range of motion.^[71]

Neck manipulations are high-velocity, short-lever thrusts with rotation beyond the physiological range of motion.^[35] High-velocity, low-amplitude spinal manipulation (HVLA-SM) thrusts have physiological effects that signal neural discharge from paraspinal muscle tissues, depending on duration and amplitude of the thrust are factors of the degree in paraspinal muscle spindles activation. Clinical skill in employing HVLA-SM thrusts depends on the ability of the practitioner to handle the duration and magnitude of the load.^[72] More generally, spinal manipulative therapy (SMT) describes techniques where the hands are used to manipulate, massage, mobilize, adjust, stimulate, apply traction to, or otherwise influence the spine and related tissues.^[71]

There are several schools of chiropractic adjustive techniques, although most chiropractors mix techniques from several schools. The following adjustive procedures were received by more than 10% of patients of licensed U.S. chiropractors in a 2003 survey:^[70] Diversified technique (full-spine manipulation, employing various techniques), extremity adjusting, Activator technique (which uses a spring-loaded tool to deliver precise adjustments to the spine), Thompson Technique (which relies on a drop table and detailed procedural protocols), Gonstead (which emphasizes evaluating the spine along with specific adjustment that avoids rotational vectors), Cox/flexion-distraction (a gentle, low-force adjusting procedure which mixes chiropractic with osteopathic principles and utilizes specialized adjusting tables with movable parts), adjustive instrument, Sacro-Occipital Technique (which models the spine as a torsion bar), Nimmo Receptor-Tonus Technique, Applied Kinesiology (which emphasises "muscle testing" as a diagnostic tool), and cranial.^[73] Medicine-assisted manipulation, such as manipulation under anesthesia, involves sedation or local anesthetic and is done by a team that includes an anesthesiologist; a 2008 systematic review did not find enough evidence to make recommendations about its use for chronic low back pain.^[74]

Many other procedures are used by chiropractors for treating the spine, other joints and tissues, and general health issues. The following procedures were received by more than one-third of patients of licensed U.S. chiropractors in a 2003 survey: Diversified technique (full-spine manipulation; mentioned in previous paragraph), physical fitness/exercise promotion, corrective or therapeutic exercise, ergonomic/postural advice, self-care strategies, activities of daily living, changing risky/unhealthy behaviors, nutritional/dietary recommendations, relaxation/stress reduction recommendations, ice pack/cryotherapy, extremity adjusting (also mentioned in previous paragraph), trigger point therapy, and disease prevention/early screening advice.^[70]

A 2010 study describing Belgium chiropractors and their patients found chiropractors in Belgium mostly focus on neuromusculoskeletal complaints in adult patients, with emphasis on the spine. The diversified technique is the most often applied technique at 93%, followed by the Activator mechanical-assisted technique at 41%.^[75] A 2009 study assessing chiropractic students giving or receiving spinal manipulations while attending a U.S. chiropractic college found Diversified, Gonstead, and upper cervical manipulations are frequently used methods.^[76]

Education, licensing, and regulation[link]

Chiropractors obtain a first professional degree in the field of chiropractic.^[77] Chiropractors often argue that this education is as good as or better than medical physicians', but most chiropractic training is confined to classrooms with much time spent learning theory, adjustment, and marketing.^[78] The curriculum content of North American chiropractic and medical colleges with regard to basic and clinical sciences has been more similar than not, both in the kinds of subjects offered and in the time assigned to each subject.^[79]

Accredited chiropractic programs in the U.S. require that applicants have 90 semester hours of undergraduate education with a grade point average of at least 3.0 on a 4.0 scale. Many programs require at least three years of undergraduate education, and more are requiring a bachelor's degree.^[80] Canada requires a minimum three years of undergraduate education for applicants, and at least 4200 instructional hours (or the equivalent) of full‐time chiropractic education for matriculation through an accredited chiropractic program.^[81]

Graduates of the Canadian Memorial Chiropractic College (CMCC) are formally recognized to have at least 7–8 years of university level education.^[82][83] The World Health Organization (WHO) guidelines suggest three major full-time educational paths culminating in either a DC, DCM, BSc, or MSc degree. Besides the full-time paths, they also suggest a conversion program for people with other health care education and limited training programs for regions where no legislation governs chiropractic.^[1]

Upon graduation, there may be a requirement to pass national, state, or provincial board examinations before being licensed to practice in a particular jurisdiction.^[84][85] Depending on the location, continuing education may be required to renew these licenses.^[86][87] Specialty training is available through part-time postgraduate education programs such as chiropractic orthopedics and sports chiropractic, and through full-time residency programs such as radiology or orthopedics.^[88]

Chiropractic is established in the U.S., Canada, and Australia, and is present to a lesser extent in many other countries.^[9] In the U.S., chiropractic schools are accredited through the Council on Chiropractic Education (CCE) while the General Chiropractic Council (GCC) is the statutory governmental body responsible for the regulation of chiropractic in the UK.^[89][90] The U.S. CCE requires a mixing curriculum, which means a straight-educated chiropractor may not be eligible for licensing in states requiring CCE accreditation.^[63]

CCEs in the U.S., Canada, Australia and Europe have joined to form CCE-International (CCE-I) as a model of accreditation standards with the goal of having credentials portable internationally.^[91] Today, there are 18 accredited Doctor of Chiropractic programs in the U.S.,^[92] 2 in Canada,^[93] 6 in Australasia,^[94] and 5 in Europe.^[95] All but one of the chiropractic colleges in the U.S. are privately funded, but in several other countries they are in government-sponsored universities and colleges.^[14]

Of the two chiropractic colleges in Canada, one is publicly funded (UQTR) and one is privately funded (CMCC). In 2005, CMCC was granted the privilege of offering a professional health care degree under the Post-secondary Education Choice and Excellence Act, which sets the program within the hierarchy of education in Canada as comparable to that of other primary contact health care professions such as medicine, dentistry and optometry.^[82][83] Chiropractic curricula in the U.S. have been criticized for failing to meet generally accepted standards of evidence-based medicine.^[96]

Regulatory colleges and chiropractic boards in the U.S., Canada, Mexico, and Australia are responsible for protecting the public, standards of practice, disciplinary issues, quality assurance and maintenance of competency.^[97][98] There are an estimated 49,000 chiropractors in the U.S. (2008),^[99] 6,500 in Canada (2010),^[100] 2,500 in Australia (2000),^[18] and 1,500 in the UK (2000).^[101]

A 2008 commentary proposed that the chiropractic profession actively regulate itself to combat abuse, fraud, and quackery, which are more prevalent in chiropractic than in other health care professions, violating the social contract between patients and physicians.^[38] A study of California disciplinary statistics during 1997–2000 reported 4.5 disciplinary actions per 1000 chiropractors per year, compared to 2.27 for MDs; the incident rate for fraud was 9 times greater among chiropractors (1.99 per 1000 chiropractors per year) than among MDs (0.20).^[102]

Utilization, satisfaction rates, and third-party coverage[link]

In the U.S., chiropractic is the largest alternative medical profession,^[7] and is the third largest doctored profession, behind medicine and dentistry.^[10] In the U.S., chiropractors perform over 90% of all manipulative treatments.^[103] The percentage of the population that utilizes chiropractic care at any given time generally falls into a range from 6% to 12% in the U.S. and Canada,^[12] with a global high of 20% in Alberta.^[104]

Chiropractors are the most common CAM providers for children and adolescents, who consume up to 14% of all visits to chiropractors.^[105] The vast majority who seek chiropractic care do so for relief from back and neck pain and other neuromusculoskeletal complaints;^[106] most do so specifically for low back pain. Practitioners such as chiropractors are often used as a complementary form of care to primary medical intervention.^[12]

Satisfaction rates are typically high for treatment of low back pain, with a 1998 U.S. survey reporting 83% of respondents satisfied or very satisfied with their care; quality of communication seems to be a consistent predictor of patient satisfaction with chiropractors.^[107] A 2011 consumer report survey found that the public considered chiropractic to outperform all other available back and neck pain treatments.^[108]

Chiropractic does not have the same level of mainstream credibility as other healthcare professions. Public perception of chiropractic compares unfavorably with mainstream medicine with regard to ethics and honesty: in a 2006 Gallup Poll of U.S. adults, chiropractors rated last among seven health care professions for being very high or high in honesty and ethical standards, with 36% of poll respondents rating chiropractors very high or high; the corresponding ratings for the other professions ranged from 62% for dentists to 84% for nurses.^{[38][109][110]}

The 2008 book Trick or Treatment states chiropractors, especially in America, have a reputation for unnecessarily treating patients, and in many circumstances the focus seems to be put on economics instead of health care.^[51] Many chiropractors have sought to address their minor status within the U.S. medical community by attending practice-building seminars to assist chiropractors to persuade their patients of the efficacy of their treatments, increase their revenue, and boost their morale as unorthodox medical practitioners.^[111] Unsubstantiated claims about the efficacy of chiropractic have continued to be made by individual chiropractors and chiropractic associations.^[16]

The largest chiropractic associations in the U.S. and Canada distributed patient brochures which contained unsubstantiated claims.^[112] Sustained chiropractic care is promoted as a preventative tool, but unnecessary manipulation could present a risk to patients. Some chiropractors are concerned by the routine unjustified claims chiropractors have made.^[16] A 2010 questionnaire presented to UK chiropractors indicated only 45% of chiropractors disclosed with patients the serious risk associated with manipulation of the cervical spine as a direct consequence of the fear that the patient would refuse treatment despite knowing the moral responsibility.^[113]

Utilization of chiropractic care is sensitive to the costs incurred by the co-payment by the patient.^[2] The use of chiropractic declined from 9.9% of U.S. adults in 1997 to 7.4% in 2002; this was the largest relative decrease among CAM professions, which overall had a stable use rate.^[114] As of 2007 only 7% of the U.S. population is being reached by chiropractic.^[115] Employment of U.S. chiropractors is expected to increase 14% between 2006 and 2016, faster than the average for all occupations.^[99]

In the U.S., most states require insurers to cover chiropractic care, and most HMOs cover these services.^[105] In Canada, there is lack of coverage under the universal public health insurance system.^[116] In Australia, most private health insurance funds cover chiropractic care, and the federal government funds chiropractic care when the patient is referred by a medical practitioner.^[117]

History[link]

D.D. Palmer

Chiropractic was founded in 1895 by Daniel David (D.D.) Palmer in Davenport, Iowa. Palmer, a magnetic healer, hypothesized that manual manipulation of the spine could cure disease.^[118] The first chiropractic patient of D.D. Palmer was Harvey Lillard, a worker in the building where Palmer's office was located. He claimed that he had severely reduced hearing for 17 years, which started soon following a "pop" in his spine. A few days following his adjustment, Lillard claimed his hearing was almost completely restored.^[43]

Chiropractic competed with its predecessor osteopathy, another medical system based on magnetic healing and bonesetting; both systems were founded by charismatic midwesterners in opposition to the conventional medicine of the day, and both postulated that manipulation improved health.^[118] Although initially keeping chiropractic a family secret, in 1898 Palmer began teaching it to a few students at his new Palmer School of Chiropractic. One student, his son Bartlett Joshua (B.J.) Palmer, became committed to promoting chiropractic, took over the Palmer School in 1906, and rapidly expanded its enrollment.^[8]

Early chiropractors believed that all disease was caused by interruptions in the flow of innate intelligence, a vital nervous energy or life force that represented God's presence in man; chiropractic leaders often invoked religious imagery and moral traditions. D.D. and B.J. both seriously considered declaring chiropractic a religion, which might have provided legal protection under the U.S. constitution, but decided against it partly to avoid confusion with Christian Science.^[8][119] Early chiropractors also tapped into the Populist movement, emphasizing craft, hard work, competition, and advertisement, aligning themselves with the common man against intellectuals and trusts, among which they included the American Medical Association (AMA).^[8]

Chiropractic has seen considerable controversy and criticism.^[13][14] Although D.D. and B.J. were "straight" and disdained the use of instruments, some early chiropractors, whom B.J. scornfully called "mixers", advocated the use of instruments. In 1910 B.J. changed course and endorsed X-rays as necessary for diagnosis; this resulted in a significant exodus from the Palmer School of the more conservative faculty and students.^[8]

The mixer camp grew until by 1924 B.J. estimated that only 3,000 of the U.S.'s 25,000 chiropractors remained straight. That year, B.J.'s invention and promotion of the neurocalometer, a temperature-sensing device, was highly controversial among B.J.'s fellow straights. By the 1930s chiropractic was the largest alternative healing profession in the U.S.^[8]

The 2008 book Trick or Treatment states that in 1913 B.J. Palmer ran over his father, D.D. Palmer, at a homecoming parade for the Palmer School of Chiropractic in Davenport, Iowa. Weeks later D.D. Palmer died in Los Angeles. The official cause of death was recorded as typhoid. The book Trick or Treatment remarked "it seems more likely that his death was a direct result of injuries caused by his son."^[51]

Chiropractic historian Joseph C. Keating, Jr. has described the attempted patricide of D.D. Palmer as a "myth" and "absurd on its face" and cites an eyewitness who recalled that D.D. was not struck by B.J.'s car, but rather, had stumbled.^[120] He also says that "Joy Loban, DC, executor of D.D.'s estate, voluntarily withdrew a civil suit claiming damages against B.J. Palmer, and that several grand juries repeatedly refused to bring criminal charges against the son."^[120]

Chiropractors faced heavy opposition from organized medicine. Thousands of chiropractors were prosecuted for practicing medicine without a license, and D.D. and many other chiropractors were jailed. To defend against medical statutes B.J. argued that chiropractic was separate and distinct from medicine, asserting that chiropractors "analyzed" rather than "diagnosed", and "adjusted" subluxations rather than "treated" disease. B.J. cofounded the Universal Chiropractors' Association (UCA) to provide legal services to arrested chiropractors. Although the UCA won their first test case in Wisconsin in 1907, prosecutions instigated by state medical boards became increasingly common and in many cases were successful. In response, chiropractors conducted political campaigns to secure separate licensing statutes, eventually succeeding in all fifty states, from Kansas in 1913 through Louisiana in 1974.^[43]

The longstanding feud between chiropractors and medical doctors continued for decades. The AMA labeled chiropractic an "unscientific cult" in 1966,^[19] and until 1980 held that it was unethical for medical doctors to associate with "unscientific practitioners".^[121] This culminated in a landmark 1987 decision, Wilk v. AMA, in which the court found that the AMA had engaged in unreasonable restraint of trade and conspiracy, and which ended the AMA's de facto boycott of chiropractic.^[20] In 2008 and 2009, chiropractors, including the British Chiropractic Association, used libel lawsuits and threats of lawsuits against their critics,^[122] however, a libel case against science writer Simon Singh ended with the BCA withdrawing its suit in 2010.^[123][124]

Research to test chiropractic theories began in 1935 with the B.J. Palmer Research Clinic at the Palmer College of Chiropractic in Davenport, Iowa. The clinic was organized into two divisions—a medical division and a chiropractic division. The medical division contained all the standard medical tests of the time and was used to establish a medical diagnosis of a patient's condition before the patient received treatment. The chiropractic division administered the treatment which included passive therapies, chiropractic adjustments and physical rehabilitation for the various conditions diagnosed. Research continued in the B.J. Palmer research clinic until B.J. Palmer's death in 1961 and the results and findings of these patient cases were the substance of B.J. Palmer's publishing over this 30 year time-period.^[125]

Attempts to further test chiropractic theories by modern standards of research began in the 1970s. By the mid 1990s there was a growing scholarly interest in chiropractic, which helped efforts to improve service quality and establish clinical guidelines that recommended manual therapies for acute low back pain.^[43]

In recent decades chiropractic gained legitimacy and greater acceptance by medical physicians and health plans, and enjoyed a strong political base and sustained demand for services. However, its future seemed uncertain: as the number of practitioners grew, evidence-based medicine insisted on treatments with demonstrated value, managed care restricted payment, and competition grew from massage therapists and other health professions. The profession responded by marketing natural products and devices more aggressively, and by reaching deeper into alternative medicine and primary care.^[20]

Evidence basis[link]

The principles of evidence-based medicine have been used to review research studies and generate practice guidelines outlining professional standards that specify which chiropractic treatments are legitimate and perhaps reimbursable under managed care.^[21] Evidence-based guidelines are supported by one end of an ideological continuum among chiropractors; the other end employs antiscientific reasoning and makes unsubstantiated claims.^{[6][15][56][126]} A 2007 survey of Alberta chiropractors found that they do not consistently apply research in practice, which may have resulted from a lack of research education and skills.^[127] Continued education enhances the scientific knowledge of the practitioner.^[128]

Effectiveness[link]

Opinions differ as to the effectiveness of chiropractic treatments. Many controlled clinical studies of spinal manipulation have been conducted, but their results often disagree^[129] and they are typically of low methodological quality.^[130] A 2010 report found that manual therapies commonly used by chiropractors are effective for the treatment of low back pain, neck pain, some kinds of headaches and a number of extremity joint conditions.^[22]

A 2008 critical review found that with the possible exception of back pain, chiropractic manipulation has not been shown to be effective for any medical condition.^[16] Health claims made by chiropractors regarding use of manipulation for pediatric health conditions are supported by only low levels of scientific evidence^[105][131] that does not demonstrate clinically relevant benefits.^[132]

Most research has focused on spinal manipulation in general,^[133] rather than solely on chiropractic manipulation.^[21] A 2002 review of randomized clinical trials of spinal manipulation^[3] was criticized for not making this distinction;^[134] however, the review's authors stated that they did not consider this difference to be a significant point as research on spinal manipulation is equally useful regardless of which practitioner provides it.^[133]

There is a wide range of ways to measure treatment outcomes.^[135] Chiropractic care, like all medical treatment, benefits from the placebo response.^[136] It is difficult to construct a trustworthy placebo for clinical trials of spinal manipulative therapy (SMT), as experts often disagree about whether a proposed placebo actually has no effect.^[137] The efficacy of maintenance care in chiropractic is unknown.^[32]

Available evidence covers the following conditions:

• Low back pain. Specific guidelines concerning the treatment of nonspecific (i.e., unknown cause) low back pain remain inconsistent between countries.^[138] A 2011 Cochrane review found strong evidence that there is no clinically meaningful difference between spinal manipulation and other treatments for reducing pain and improving function for chronic low back pain.^[23] A 2010 Cochrane review found no current evidence to support or refute a clinically significant difference between the effects of combined chiropractic interventions and other interventions for chronic or mixed duration low back pain.^[139] A 2010 systematic review found that most studies suggest spinal manipulation achieves equivalent or superior improvement in pain and function when compared with other commonly used interventions for short, intermediate, and long-term follow-up.^[24] A 2008 review found strong evidence that SM is similar in effect to medical care with exercise.^[140] A 2008 literature synthesis found good evidence supporting SM for low back pain regardless of duration.^[141] A 2007 review found good evidence that SM is moderately effective for low back pain lasting more than 4 weeks.^[142] In 2007 the American College of Physicians and the American Pain Society recommended that clinicians consider the addition of spinal manipulation for patients who do not improve with self care options.^[143] Methods for formulating treatment guidelines for low back pain differ significantly between countries, casting some doubt on their reliability.^[138]

• Radiculopathy. There is no overall consensus on the effectiveness of manual therapies for radiculopathies. There is moderate quality evidence to support the use of spinal manipulation for the treatment of acute lumbar radiculopathy^[25] and acute lumbar disc herniation with associated radiculopathy.^[26] The evidence for chronic lumbar spine-related extremity symptoms and cervical spine-related extremity symptoms of any duration is low or very low and no evidence exists for the treatment of thoracic radiculopathy.^[25]

• Whiplash and other neck pain. There is no overall consensus on the effectiveness of manual therapies for neck pain.^[144] A 2011 systematic review concluded that thoracic spine manipulation may provide short-term improvement in patients with acute or subacute mechanical neck pain; although the body of literature is still weak.^[145] A 2010 Cochrane review found low evidence that manipulation was more effective than a control for neck pain, and moderate evidence that cervical manipulation and mobilisation produced similar effects on pain, function and patient satisfaction.^[27] A 2010 systematic review found low level evidence that suggests chiropractic care improves cervical range of motion and pain in the management of whiplash.^[146] A 2009 systematic review of controlled clinical trials found no evidence that chiropractic spinal manipulation is effective for whiplash injury.^[147] A 2008 review found evidence that suggests that manual therapy and exercise are more effective than alternative strategies for patients with neck pain.^[148] A 2007 review found that spinal manipulation and mobilization are effective for neck pain.^[144] A 2005 review found evidence supporting spinal mobilization, and limited evidence supporting spinal manipulation for whiplash.^[149]

• Headache. There is no overall consensus on the effectiveness of manual therapies for headaches. Of two systematic reviews published in 2011, one found evidence that spinal manipulation might be as effective as propranolol or topiramate in the prevention of migraine headaches,^[28] the other concluded that evidence does not support the use of spinal manipulation for the treatment of migraine headaches.^[150] A 2004 Cochrane review found evidence that suggests spinal manipulation may be effective for migraine, tension headache and cervicogenic headache.^[29] A 2006 review found inconclusive evidence supporting manual therapies for tension headache.^[151] A 2005 review found that spinal manipulation showed a trend toward benefit in the treatment of tension headache, but the evidence was weak.^[152]

• Extremity conditions. A 2011 systematic review and meta-analysis concluded that the addition of manual mobilizations to an exercise program for the treatment of knee osteoarthritis resulted in better pain relief then a supervised exercise program alone and suggested that manual therapists consider adding manual mobilisation to optimise supervised active exercise programs.^[153] There is silver level evidence that manual therapy is more effective than exercise for the treatment of hip osteoarthritis, however this evidence could be considered to be inconclusive.^[154] A 2008 systematic review found that the addition of cervical spine mobilization to a treatment regimen for lateral epicondylosis (tennis elbow) resulted in significantly better pain relief and functional improvements in both the short and long-term.^[155] There is a small amount of research into the efficacy of chiropractic treatment for upper limbs,^[156] limited to low level evidence supporting chiropractic management of shoulder pain^[31] and limited or fair evidence supporting chiropractic management of leg conditions.^[30]

• Other. A 2012 systematic review found insufficient low bias evidence to support the use of spinal manipulation as a therapy for the treatment of hypertension.^[157] A systematic review in 2011 found moderate evidence to support the use of manual therapy for cervicogenic dizziness.^[158] There is very weak evidence for chiropractic care for adult scoliosis (curved or rotated spine)^[159] and no scientific data for idiopathic adolescent scoliosis.^[160] A 2007 systematic review found that few studies of chiropractic care for nonmusculoskeletal conditions are available, and they are typically not of high quality; it also found that the entire clinical encounter of chiropractic care (as opposed to just SM) provides benefit to patients with cervicogenic dizziness, and that the evidence from reviews is negative, or too weak to draw conclusions, for a wide variety of other nonmusculoskeletal conditions, including ADHD/learning disabilities, dizziness, high blood pressure, and vision conditions.^[161] Other reviews have found no evidence of significant benefit for asthma,^[162] baby colic,^[131][163] bedwetting,^[164] carpal tunnel syndrome,^[165] fibromyalgia,^[166] gastrointestinal disorders,^[167] kinetic imbalance due to suboccipital strain (KISS) in infants,^[131][168] menstrual cramps,^[169] or pelvic and back pain during pregnancy.^[170]

Safety[link]

Chiropractic care in general is safe when employed skillfully and appropriately. Manipulation is regarded as relatively safe, but as with all therapeutic interventions, complications can arise, and it has known adverse effects, risks and contraindications. Absolute contraindications to spinal manipulative therapy are conditions that should not be manipulated; these contraindications include rheumatoid arthritis and conditions known to result in unstable joints.^[1]

Relative contraindications are conditions where increased risk is acceptable in some situations and where low-force and soft-tissue techniques are treatments of choice; these contraindications include osteoporosis.^[1] Although most contraindications apply only to manipulation of the affected region, some neurological signs indicate referral to emergency medical services; these include sudden and severe headache or neck pain unlike that previously experienced.^[34]

Spinal manipulation is associated with frequent, mild and temporary adverse effects,^[33][34] including new or worsening pain or stiffness in the affected region.^[171] They have been estimated to occur in 33% to 61% of patients, and frequently occur within an hour of treatment and disappear within 24 to 48 hours;^[172] adverse reactions appear to be more common following manipulation than mobilization.^[173] Chiropractors are more commonly associated with serious manipulation related adverse effects than other professionals.^[35]

Rarely,^[1] spinal manipulation, particularly on the upper spine, can also result in complications that can lead to permanent disability or death; these can occur in adults^[33] and children.^[174] Estimates vary widely for the incidence of these complications,^[172] and the actual incidence is unknown, due to high levels of underreporting and to the difficulty of linking manipulation to adverse effects such as stroke.^[33] Adverse effects are poorly reported in recent studies investigating chiropractic manipulations.^[175] Estimates for serious adverse events vary from 5 strokes in 100,000 manipulations to 1.46 serious adverse events in 10,000,000 manipulations and 2.68 deaths in 10,000,000 manipulations.^[172]

Several case reports show temporal associations between interventions and potentially serious complications. Vertebrobasilar artery stroke is statistically associated with chiropractic services in persons under 45 years of age, but it is similarly associated with general practitioner services, suggesting that these associations are likely explained by preexisting conditions.^[148][176] Weak to moderately strong evidence supports causation (as opposed to statistical association) between cervical manipulative therapy and vertebrobasilar artery stroke.^[177]

The published medical literature contains reports of 26 deaths since 1934 following chiropractic manipulations and many more seem to remain unpublished. Many chiropractors claim that, the association between chiropractic therapy and arterial dissection is not proven. However, the causality between chiropratic neck manipulation beyond the normal range of motion and vascular accidents is probable^[35] or definite.^[178]

Chiropractors, like other primary care providers, sometimes employ diagnostic imaging techniques such as X-rays and CT scans that rely on ionizing radiation.^[179] Although there is no clear evidence for the practice, some chiropractors may still X-ray a patient several times a year.^[51] Research suggests that most chiropractors in Canada are taught and follow stringent radiography guidelines,^[180] which were developed to reduce unnecessary radiography.^[179]

Risk-benefit[link]

A 2010 systematic review stated that there is no good evidence to assume that neck manipulation is an effective treatment for any medical condition and suggested a precautionary principle in healthcare for chiropractic intervention even if a causality with vertebral artery dissection after neck manipulation were merely a remote possibility.^[35] The same review concluded that the risk of death from manipulations to the neck outweighs the benefits.^[35] Chiropractors have criticized this conclusion, claiming that the author did not evaluate the potential benefits of spinal manipulation.^[181]

Professor Edzard Ernst of the University of Exeter stated "This detail was not the subject of my review. I do, however, refer to such evaluations and should add that a report recently commissioned by the General Chiropractic Council did not support many of the outlandish claims made by many chiropractors across the world."^[181] A 2009 review evaluating maintenance chiropractic care found that spinal manipulation is routinely associated with considerable harm and no compelling evidence exists to indicate that it adequately prevents symptoms or diseases, thus the risk-benefit is not evidently favorable.^[182]

A 2008 summary found that the best evidence suggests that chiropractic care is a useful therapy for subjects with neck or low-back pain for which the risks of serious adverse events should be considered negligible.^[183] A 2007 systematic review found that with uncertain efficacy and definite risks, the risk-benefit balance of spinal manipulation can't be positive.^[33] A 2006 systematic review of systematic reviews found the risk-benefit balance does not favor spinal manipulation over other treatments like physical therapy.^[129]

Cost-effectiveness[link]

A 2012 systematic review suggested that the use of spine manipulation in clinical practice is a cost-effective treatment when used alone or in combination with other treatment approaches.^[184] A 2011 systematic review found evidence supporting the cost-effectiveness of using spinal manipulation for the treatment of sub-acute or chronic low back pain; the results for acute low back pain were inconsistent.^[185] A 2006 qualitative review found that the research literature suggests that chiropractic obtains at least comparable outcomes to alternatives with potential cost savings.^[186]

A 2006 systematic cost-effectiveness review found that the reported cost-effectiveness of chiropractic manipulation in the United Kingdom compared favorably with other treatments for back pain, but that reports were based on data from clinical trials without sham controls and that the specific cost-effectiveness of the treatment (as opposed to non-specific effects) remains uncertain.^[187] A 2005 systematic review of economic evaluations of conservative treatments for low back pain found that significant quality problems in available studies meant that definite conclusions could not be drawn about the most cost-effective intervention.^[188] The cost-effectiveness of maintenance chiropractic care is unknown.^[32]

Public health[link]

Some chiropractors oppose vaccination and water fluoridation, which are common public health practices.^[38] Within the chiropractic community there are significant disagreements about vaccination,^[17][18] one of the most cost-effective public health interventions available.^[189] Most chiropractic writings on vaccination focus on its negative aspects,^[17] claiming that it is hazardous, ineffective, and unnecessary. Some chiropractors have embraced vaccination, but a significant portion of the profession rejects it, as original chiropractic philosophy traces diseases to causes in the spine and states that vaccines interfere with healing.^[18]

The extent to which anti-vaccination views sustain the current chiropractic profession is uncertain.^[17] The American Chiropractic Association and the International Chiropractors Association support individual exemptions to compulsory vaccination laws, and a 1995 survey of U.S. chiropractors found that about a third believed there was no scientific proof that immunization prevents disease.^[18] The Canadian Chiropractic Association supports vaccination;^[17] a survey in Alberta in 2002 found that 25% of chiropractors advised patients for, and 27% against, vaccinating themselves or their children.^[190]

Early opposition to water fluoridation included chiropractors, some of whom continue to oppose it as being incompatible with chiropractic philosophy and an infringement of personal freedom. Other chiropractors have actively promoted fluoridation, and several chiropractic organizations have endorsed scientific principles of public health.^[191]

In addition to traditional chiropractic opposition to water fluoridation and vaccination, chiropractors' attempts to establish a positive reputation for their public health role are also compromised by their reputation for recommending repetitive life-long chiropractic treatment.^[38]

Controversy and criticism[link]

Throughout its history chiropractic has been the subject of internal and external controversy and criticism.^[7][192] According to Daniel D. Palmer, the founder of chiropractic, subluxation is the sole cause of disease and manipulation is the cure for all diseases of the human race.^[16] A critical evaluation stated "Chiropractic is rooted in mystical concepts. This led to an internal conflict within the chiropractic profession, which continues today."^[16] Chiropractors, including D.D. Palmer, were jailed for practicing medicine without a license.^[16] For most of its existence, chiropractic has battled with mainstream medicine, sustained by antiscientific and pseudoscientific ideas such as subluxation.^[43] Chiropractic has been controversial, though to a lesser extent than in past years.^[193]

Chiropractic authors have stated that fraud, abuse and quackery are more prevalent in chiropractic than in other health care professions.^[38] Unsubstantiated claims about the efficacy of chiropractic have continued to be made by individual chiropractors and chiropractic associations. The core concept of traditional chiropractic, vertebral subluxation, is not based on sound science. The biomechanical listing systems taught in chiropractic college technique offerings have been criticized as inaccurate, inadequate and invalid.^[194] A critical evaluation found that research has not demonstrated that spinal manipulation, the main treatment method employed by chiropractors, is effective for any medical condition, with the possible exception of treatment for back pain.,^[16] whereas, another review found manual therapies in general to be effective for back pain, neck pain, some forms of headaches and some extremity joint conditions.^[22] Although rare,^[1] spinal manipulation, particularly on the upper spine, can also result in complications that can lead to permanent disability or death; these can occur in adults^[33] and children.^[174]

References[link]