Overview: Chiropractic is a health care discipline that focuses on the relationship between musculoskeletal structure (primarily the spine) and body function (as coordinated by the nervous system), and how this relationship affects the preservation and restoration of health. The broad term "spinal manipulative therapy" incorporates all types of manual techniques, including chiropractic.
History: Spinal manipulation was used medicinally as early as 2700 B.C. in ancient Chinese medicine. Hippocrates and Galen used manipulative techniques, and the word "chiropractic" is derived from Greek chiropraktikos, meaning "effective treatment by hand."
In the late 1800s, David Daniel Palmer systematized the principles upon which modern chiropractic is based, suggesting that abnormal nerve function is the primary cause of disorders, and recommending adjustment of the spine as an effective therapy. The Palmer School of Chiropractic opened in 1895, and one-third of students were physicians. Acceptance of Palmer's principles in the medical community varied, and some early chiropractors were imprisoned (including Palmer himself). A schism between chiropractors and medical doctors persisted, and between 1977-1987, an antitrust lawsuit was brought against the American Medical Association for systematic bias against the chiropractic profession (which was ultimately successful).
Divisions existed within the chiropractic community as well, and during the early 20th century, two schools of thought emerged: One group ("straights") asserted that subluxation is the underlying cause of disease. A second group ("mixers") worked in a multidisciplinary setting with physicians, and accepted other pathophysiologic theories of disease. Two different chiropractic associations were founded between 1920-1926 reflecting this division: the International Chiropractic Association (ICA) and the American Chiropractic Association (ACA), respectively.
In 1972, chiropractic treatment became reimbursable by Medicare. In 1974, nationally recognized standards were adopted by the Council on Chiropractic Education (CCE), and were recognized by the U.S. Department of Education. All U.S. chiropractic colleges achieved accreditation by the CCE by 1975. Currently, all 50 U.S. states have statutes recognizing and regulating the practice of chiropractic.
Currently: In the United States, chiropractors are the most frequently used non-physician primary health providers, after dentists (1;2). There are more than 60,000 licensed American chiropractors (3), a number expected to reach 100,000 by 2010 (4). Almost 80% of all visits to chiropractors are for musculoskeletal complaints (5), and more than 40% are for back pain (6). In 1999, 11% of adults and more than 30% of patients with low back pain visited a chiropractor (7). For two-thirds of patients, a chiropractor was the only provider seen for these complaints (8).
The cost effectiveness of chiropractic care remains controversial and is not clearly established (9-12).
Techniques: There are more than 100 distinct chiropractic and spinal manipulative adjusting techniques, and there is variability between practitioners. Some approaches use highly specialized tables or hand-held equipment. Techniques that are widely taught in chiropractic schools include: Diversified, Extremity Adjusting, Activator, Gonstead, Cox Flexion-Distraction, and Thompson. Other techniques are taught on chiropractic campuses outside of the established curriculum, and many are taught in seminars that are not sanctioned as a part of the established chiropractic curriculum. Categories of therapeutic approaches include the following:
Manipulation: A primary chiropractic therapeutic application that involves applying a specific amount of force vectored through a specific plane of motion of a spinal or peripheral joint, in order to reduce joint restriction and facilitate normal range of motion. Long-lever manipulation uses the femur, shoulder, head, or pelvis to affect larger sections of the spine in a non-specific manner. Specific short lever, dynamic thrusts utilize a specific contact on a transverse spinous process of vertebra, muscle, or ligament. Point pressure manipulation includes the gouging or manual stimulation of specific points without attempting to actually massage a muscle or move a joint.
Mechanical traction: A technique that incorporates the use of an external system of applied resistance to facilitate joint decompression of the spine or extremity. Manual traction is often performed on a segment of the spine without attempting to mobilize the joint through a specific passive movement.
Massage/soft tissue mobilization: A category of soft tissue therapeutic techniques used to reduce muscle spasm, soreness, or tightness. These procedures are directed at the subcutaneous, muscular, or tendinous tissues and do not result in significant joint movement. Example techniques include myofascial trigger point therapy, cross friction massage, active release therapy, muscle stripping, and rolfing. Mobilization or articulation technique uses slow rhythmic movements rather than quick sharp thrusts, and may be performed within the passive range of motion of the spine.
Electrical muscle stimulation (EMS)/interferential therapy: A therapeutic modality using two medium-frequency currents that intersect. The intersecting current is believed by some practitioners to reduce muscle spasm and pain.
Diathermy: A technique that uses high-frequency electrical currents to produce specific "thermal" effects.
Ultrasound: A technique that uses high-frequency sound waves with the goal of producing "micromassage" and "deep tissue heat."
Cryotherapy: A technique that uses ice therapy or icepacks for control of joint pain and inflammation.
Hydroculator packs: A technique that uses therapeutic heat application.
Rehabilitation/exercise prescription: Exercise-based programs designed to improve function (rehabilitation programs) are sometimes used as part of an overall management strategy.
Dietary counseling/nutritional support: Weight modulation and dietary change may be recommended as part of an overall management strategy.
Health promotion/preventative services: Chiropractors often provide health promotion and prevention services, including an emphasis on exercise, adjustment/manipulation, dietary advice, vitamins, and relaxation.
Diagnostic procedures: Chiropractors use a number of diagnostic imaging tests, including x-ray, computerized tomography (CT) scans, magnetic resonance imaging (MRI), and thermography.
Chiropractic adjustment, chiropractic manipulation, chiropractic manipulative therapy, chiropractic spinal manipulation, manual physiotherapy, manual therapy, spinal adjustive manipulation, spinal manipulation, spinal manipulative therapy, SMT.
Not included in this review: Osteopathic manipulative therapy, mobilization, mobilization therapy, physical therapy. Traction is a physical modality used primarily in physical therapy, and is inconsistently utilized in chiropractic offices.