Chiropractic is a form of therapeutic manipulation that primarily treats skeletal and muscular problems (Hansen and Triano 2000). Once highly criticized and even alienated from the allopathic medical community, chiropractic now has gained greater acceptance in both the mainstream medical establishment and the eyes of the public. Today, chiropractic is the third largest independent health profession in the Western world; the United States alone is home to 52,000 licensed chiropractors who collectively see over 20 million patients a year (Redwood 1996).

Spinal manipulation, the basis of chiropractic care, has been practiced throughout the world for thousands of years. Hippocrates and Galen, the famous Greek and Roman physicians, used such hands-on treatments to reposition the spine, thereby treating a wide range of maladies (Redwood 1996). In 1895 in Davenport, Iowa, Daniel Palmer reportedly cured a man of back pain and deafness by pressing on a protruding vertebra, thus establishing the form of chiropractic now practiced in the U.S. Around the turn of the 20^th century, alternative modes of healing, including homeopathy, osteopathy, herbal medicine, and magnetic healing, also were widely utilized (Hansen and Triano 2000). The emerging medical professionals viewed chiropractic and these alternative modalities with a mixture of skepticism and ridicule. This early history, coupled with disagreement among chiropractors about the physiologic principles and scope of practice, continued to divide the profession until fairly recently (Hansen and Triano 2000; Kaptchuk and Eisenberg 1998).

Conventional physicians were so opposed to chiropractic that the American Medical Association (AMA) actually staged a boycott, forbidding its members to refer patients to chiropractors or accept referrals from them. For decades, medical schools taught that chiropractic was harmful or, at best, worthless. The relationship between the two professions changed in 1990, when the U.S. Supreme Court ruled that the AMA's boycott represented an anti-trust violation for engaging in a conspiracy to contain and eliminate the chiropractic profession. The AMA was ordered to reverse its historic ban on inter-professional cooperation with chiropractic doctors and to publish the court's findings in the Journal of the American Medical Association (JAMA) (Redwood 1996). As a result of this ruling and the development of high quality chiropractic research, professional cooperation began to improve, and today Medicare and most health insurance companies cover chiropractic (Hansen and Triano 2000). This change of events reflects what increasingly large numbers of the population already believe: that chiropractic is a safe and effective modality for a range of health problems (Redwood 1996).

Chiropractic is based on the principle that vertebral subluxations, or joint dysfunctions, interfere with nerve transmission and disturb normal body function (Ofman 1999). The definition of subluxations has been expanded beyond the original concept of vertebral malposition to include mechanical impediments that affect mobility, posture, blood flow, and muscle tone (Kaptchuk and Eisenberg 1998). However, there are two opinions among chiropractors regarding the proper role of the chiropractor. The primary difference between the two groups is the degree to which chiropractors should focus on symptom relief. Traditionalist or "straight" chiropractors see their approach as being subluxation-based rather than symptom-driven, and largely confine their role to analyzing the spine for subluxations and then manually adjusting the subluxated vertebrae (Redwood 1996).

Both groups agree that spinal adjusting is the paramount feature of chiropractic practice, and that advising patients on exercise and natural diet is appropriately within the chiropractor's scope. Broad-scope modernists seek to treat both the cause and the symptom, contending that patient care is in some instances enhanced by such adjuncts as electrical physical therapy modalities, hands-on muscle therapies, acupuncture, and nutritional regimes including supplementation with vitamins, minerals, and herbs (Redwood 1996).

Chiropractors employ a wide range of spinal adjustments, including moving a joint to the end point of its range of motion, isolating it by applying localized pressure, and then thrusting it into a new position. These adjustments may alleviate stress and inflammation; improve the function of the affected muscles, joints, ligaments, and nerves; reduce pain; relax muscle spasm; and restore range of motion. Chiropractors also assert that adjustments can transmit nerve impulses along the autonomic nerve pathways, thus in some cases restoring proper function of the internal organs and promoting the body's own healing abilities, its "innate intelligence" (Redwood 1996).

The initial visit to a chiropractor is similar in many respects to a typical doctor's visit. The chiropractor takes the patient's complete medical history and checks the vital signs, such as height, weight, blood pressure, pulse, temperature, and respiratory rate. The chiropractor then conducts a detailed examination of the spine and related structures to determine the severity of the problem. Other tests, such as blood and urine sampling, radiograph, MRI, and CT scan, may also be recommended (Hansen and Triano 2000). The initial and subsequent visits are likely to include high velocity, low amplitude thrusts or, when appropriate, low force adjustments, and continual reevaluation of the presenting problem. If inflammation or muscle spasms are present, the chiropractor may employ ultrasound, electric stimulation, vibration, stretching exercises, moist heat, cold packs, or massage before or after spinal adjustments (Hansen and Triano 2000; Kaptchuk and Eisenberg 1998). Recommendations for bed rest, corrective exercise, fitness, nutrition, and stress management may also be made.

The frequency of visits is tailored to the needs of the individual patient. A typical course of care might involve two to five visits per week for one to two weeks, followed by one to two visits per week for two to three weeks. The frequency of visits generally decreases until the problem is resolved (Hansen and Triano 2000); occasionally, a chiropractor may recommend monthly maintenance or some other maintenance schedule to prevent recurrence of spinal problems (Rupert 2000). When appropriate, the chiropractor may refer the patient to a neurologist, a neurosurgeon, an orthopedic surgeon, an internist, or to other conventional or complementary medical specialists (Redwood 1996).

Ninety-five percent of chiropractic visits are for musculoskeletal disorders and injuries that result in headaches and lower back, neck, leg, or arm pain (Hansen and Triano 2000). Such disorders and injuries are the major cause of chronic health problems, long-term disability, and healthcare visits, and a major cause of short-term disability and the use of prescription and non-prescription pain-relief drugs (Manga 2000).

Spinal manipulation is one of the most extensively studied modalities in alternative medicine (Lauretti 1997). Over 40 controlled trials have shown it to be especially effective for back pain, the second most common ailment for which patients seek alternative therapy. Research also shows that chiropractic can improve function and provide a faster recovery from back pain than other modalities. In two studies that compared patient satisfaction with treatment provided by chiropractors, orthopedists, and primary care physicians, patients reported greater satisfaction with chiropractic than the other modalities (Ofman 1999).

In addition, randomized, controlled trials have demonstrated that people with chronic tension headaches and migraines experience longer-term improvement and fewer side effects with chiropractic care than with pharmaceutical intervention (Boline et al. 1995; Nelson et al. 1998), that shoulder girdle problems are helped by chiropractic manipulation of the neck, upper back, and shoulder (Winters et al. 1997), and that chiropractic is effective for treating infantile colic (Wiberg et al. 1999). Research has also suggested that head and neck adjustment may have beneficial effects in treating otitis media (Fallon 1997).

Case reports and anecdotal information suggest that chiropractic may also be a helpful adjunct for arthritis, chronic fatigue syndrome, hypertension, menopause, menstrual disorders, periodic leg movement syndrome, pregnancy and childbirth concerns, premenstrual syndrome, rheumatoid arthritis, sprains, tendonitis, tenosynovitis, vision disorders, and temporomandibular joint disorder (TMJ) (Hansen and Triano 2000).

Chiropractic may be useful as a preventive therapy, as well; research indicates that chiropractors are more involved in health promotion and prevention education than conventional physicians (Manga 2000).

Studies indicate that chiropractic is generally safer than medication for treatment of pain (Gottlieb 1997). Side effects and adverse events are not common, although some patients may experience minor aches, muscle fatigue, and stiffness for a few days following manipulation. Although extremely rare, individual cases of stroke and spinal cord damage have been reported from neck manipulation, at a rate of less than 1 per one-million treatments (Hansen and Triano 2000). The risk of severe neurological complications, such as cauda equina syndrome, is 1 per 100 million spinal manipulations (Ofman 1999).

Contraindications to chiropractic include fractures, bone tumors, bone and joint infections, and acute cauda equina syndrome (Redwood 1996). Those with acute myelopathy, advanced osteoporosis, cancer, congenital or acquired deformities, undiagnosed or progressive neurological deficits, and vertebral-basilar syndrome, should not receive chiropractic in the area of the problem (Hansen and Triano 2000). Patients with a history of hypertension and those receiving heparin therapy, should be monitored closely while receiving chiropractic treatments (Plaugher and Bachman 1993). Dislocations, acute rheumatoid arthritis, ankylosing spondylitis, acute juvenile avascular necrosis, and unstable osodontoideum are also contraindications for chiropractic care (Redwood 1996).

There are 16 chiropractic schools in the U.S. accredited by the Council on Chiropractic Education (Hansen and Triano 2000), along with two schools in Canada and more than a dozen overseas. A chiropractic degree requires approximately the same number of total educational hours as a medical degree. After completing at least two years of regular college study, those seeking a chiropractic degree must complete a four- or five-year program that includes basic sciences, clinical experience, and standard, as well as structural (spinal) and functional (nervous system), diagnoses (Redwood 1996). Graduates must pass rigorous examinations administered by the National Board of Chiropractic Examiners. All 50 states license chiropractors and regulate the integrity of their practice, education, and clinical experience (Hansen and Triano 2000).

For more information, contact the American Chiropractic Association in Arlington, VA 800-986-4636 or on the Web at www.amerchiro.org or the International Chiropractors Association in Arlington, VA 800-423-4690 or on the Web at www.chiropractic.org. You can also review an outline of or order the Agency for Health Care Policy and Research's monograph on chiropractic training, practice, and research on the Web at www.ahcpr.gov/clinic/chiropr.htm.

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