Manipulation of the spine is the main technique in today's chiropractic adjustment, or treatment. Though its use has been documented from the time of the ancient Egyptians, spinal manipulation in an attempt to correct the theoretical vertebral subluxation is solely a chiropractic endeavor. Chiropractic's contribution to the field of manipulative therapies is the concept of applying a precise adjustment to a specific affected vertebra, as opposed to the generalized maneuvers of the early osteopaths. While some chiropractors adhere strictly to the use of only spinal manipulation in their adjustment, others include a broad range of methods directed at correcting the subluxation and/or just relieving musculoskeletal pain.
Some chiropractors specialize in treating specific musculoskeletal problems or sports injuries, or they may combine chiropractic with manipulation of the extremities, physiotherapy, nutrition, or exercises to increase spinal strength or improve overall health. Some also use other complementary and alternative methods as a part of a holistic treatment approach. However, chiropractors do not prescribe drugs; they believe this to be the province of conventional medicine, and that their role is to pursue drug-free alternative treatments. Depending on the country or state in which the Chiropractic school is located, some train in minor surgery. When indicated, the doctor of chiropractic consults with, co-manages, or refers to other health care providers.
Chiropractic was founded in 1895 by Daniel David Palmer, based on his assertion that all health problems could be prevented or treated using "adjustments" of the spine, and sometimes other joints, to correct what he termed "subluxations." He, and later his son, B.J. Palmer, proposed that subluxations were misaligned vertebrae which caused nerve compression that interfered with the transmission of what he named Innate Intelligence. This interference interrupted the proper flow of Innate Intelligence from "above, down, inside, and out" to the organ to which it traveled. As a result, the human body would experience "dis-ease" or disharmony which would result in loss of health. He compared this process to stepping on a hose that slowed the flow of water to a garden: if you take your foot off the hose, the flow returns to normal and the garden will flourish.
While the "pinched garden hose theory" has mostly been abandoned, it is still used in a modified form by some chiropractors to explain vertebral subluxation. However, the concept of the subluxation, which has marginal evidence, remains integral to typical chiropractic practice, and in 2003 90% of chiropractors believed the vertebral subluxation complex played a significant role in all or most diseases.
There is evidence that spinal manipulation is effective for the treatment of acute low back pain, tension headaches and some musculoskeletal issues, but not all studies support this conclusion. There are no objective controlled trials with definitive conclusions for or against chiropractic claims concerning other health benefits.
Today, there are 17 accredited chiropractic colleges in the USA and two in Canada, and an estimated 70,000 chiropractors in the USA, 5000 in Canada, 2500 in Australia, 1300 in the UK, and smaller numbers in about 50 other countries. In the USA and Canada, licensed individuals who practice chiropractic are commonly referred to as chiropractors, doctors of chiropractic, (DC) or chiropractic physicians.
There are four main groups of chiropractors: "traditional straights", "objective straights", "mixers", and "reform". All groups, except reform, treat patients using a subluxation-based system. Differences are based on the philosophy for adjusting, claims made about the effects of those adjustments, and various additional treatments provided along with the adjustment.
Chiropractic's approach to healthcare
According to Robert Mootz DC and Reed Phillips DC, Phd, although chiropractic has much in common with other health professions, its philosophical approach distinguishes it from modern medicine. Chiropractic philosophy involves what has been described as a "contextual, naturopathic approach" to health care. The traditional, "allopathic" or "medical" model considers disease as generally the result of some external influence, such as a toxin, a parasite, an allergen, or an infectious agent: the solution is to counter the perceived environmental factor (e.g., using an antibiotic for a bacterial infection). By contrast, the naturopathic approach considers that lowered "host resistance" is necessary for disease to occur, so the appropriate solution is to direct treatment to strengthen the host, regardless of the environment. In contemporary clinical practice, one can find elements of both naturopathic and allopathic philosophy among all types of providers. The degree to which a practitioner emphasizes different tenets of these philosophies is one factor that determines the manner in which they practice.
Chiropractic Perspectives That Reflect a Holistic Approach to Patient Care
- noninvasive, emphasizes patient's inherent recuperative abilities
- recognizes dynamics between lifestyle, environment, and health
- emphasizes understanding the cause of illness in an effort to eradicate, rather than palliate, associated symptoms
- recognizes the centrality of the nervous system and its intimate relationship with both the structural and regulatory capacities of the body
- appreciates the multifactorial nature of influences (structural, chemical, and psychological) on the nervous system
- balances the benefits against the risks of clinical interventions
- recognizes as imperative the need to monitor progress and effectiveness through appropriate diagnostic procedures
- prevents unnecessary barriers in the doctor-patient encounter
- emphasizes a patient-centered, hands-on approach intent on influencing function through structure
- strives toward early intervention, emphasizing timely diagnosis and treatment of functional, reversible conditions
Source:AHCPR Chapter 2 Chiropractic Belief Systems, Robert D. Mootz DC; Reed B. Phillips DC, PhD
Most patients who visit a chiropractor do so initially because of symptoms arising from musculoskeletal problems (especially low back and neck pain), although most chiropractors say they concern themselves with the overall health of the patient. According to a survey by the National Center for Complementary and Alternative Medicine, in 2002, chiropractic was the fourth (7.5%) most commonly used CAM therapy among adults in the USA. The profession has evolved so that treatment consists of hundreds of different techniques. The U.S. Department of Labor's Occupational Outlook Handbook said:
Because chiropractors emphasize the importance of healthy lifestyles and do not prescribe drugs or perform surgery, chiropractic care is appealing to many health-conscious Americans. Chiropractic treatment of the back, neck, extremities, and joints has become more accepted as a result of research and changing attitudes about alternative, noninvasive health care practices. Most DCs are self employed or work in small groups, employing chiropractic assistants as office staff and to perform therapeutic activities. They may also employ massage and physiotherapists as adjuncts to chiropractic care.
American Medical Association (AMA)
In 1997, the following statement was adopted as policy of the AMA after a report on a number of alternative therapies:
Specifically about chiropractic it said,
"Manipulation has been shown to have a reasonably good degree of efficacy in ameliorating back pain, headache, and similar musculoskeletal complaints." In 1992, the AMA issued this statement:
"It is ethical for a physician to associate professionally with chiropractors provided that the physician believes that such association is in the best interests of his or her patient. A physician may refer a patient for diagnostic or therapeutic services to a chiropractor permitted by law to furnish such services whenever the physician believes that this may benefit his or her patient. Physicians may also ethically teach in recognized schools of chiropractic. (V, VI)"
Federation of Chiropractic Licensing Boards
The FCLB is a conglomeration of all 50 US state licensing boards and the District of Columbia. It also includes several Canadian provinces and US territories. Its stated purpose is to protect the public and to serve the member boards by promoting excellence in chiropractic regulation.
Each state has a regulatory board that is appointed by its Governor. The board's responsibilities include:
- to investigate consumer complaints;
- to oversee the general application of health care laws;
- to help update and develop regulations which better define appropriate conduct by professionals and clarify what the consumer may expect;
- to continually review required credentials for doctors to practice safely, effectively, and ethically;
- to apply appropriate disciplinary action or retraining to doctors who may have broken the public trust through violation of statute or regulation;
- to function in the global regulatory community to assist other professions or jurisdictions affected by chiropractic.
The requirements to enter licensed chiropractic practice are defined by laws and regulations designed to protect the public's health, safety and welfare.
The public may contact the licensing board in each jurisdiction to determine the status of the doctor's license. The Federation also maintains an on-line, international databank, known as CIN-BAD. This databank carries information on public actions by chiropractic regulatory agencies related to licenses of individual practitioners. It also lists doctors prohibited from receiving Medicare reimbursement due to federal sanctions imposed by U.S. Department of Health & Human Services. Members of the public may use a query form to request a search of the database.
Practice styles and schools of thought
Contemporary chiropractic can be divided into several approaches to patient care: all are based on non-invasive, non-medication approaches, with many based on the use of manipulation as a treatment for mechanical musculoskeletal dysfunction of the spine and extremities. Most chiropractors advertise themselves as primary care doctors, and consider themselves part of "alternative health care", but there can be large differences between practitioners. The differences between straights and mixers are reflected in multiple national practice associations, but most chiropractors are not members of any national organization.
Traditional Straight chiropractors are the oldest movement; they adhere to the tenets, set forth by DD and BJ Palmer, that vertebral subluxation leads to interference of the human nervous system and is a primary underlying risk factor for almost any disease. Straights view the diagnosis of patient complaints, which they consider to be "secondary effects", to be unnecessary for treatment. Instead, patients are typically screened for "red flags" of serious disease, and treated based on a practitioner's preferred chiropractic technique. This stance against diagnosing has been a source of contention between mixers and straights, because accreditation standards mandate that differential diagnosis be taught in all chiropractic programs so that patient care is safe and relevant to their complaints. Additionally, several state chiropractic licensing boards mandate that patient complaints be diagnosed before receiving care. The most popular national association for traditional straights is the International Chiropractors Association (ICA).
Mixing chiropractors are an early offshoot of the straight movement. This branch originated from naturopathic, osteopathic, medical, and even chiropractic doctors who attended the Palmer College of Chiropractic and then re-organized the treatment system to include more diagnostic and treatment approaches. They eventually split from the traditional straight group and formed various other chiropractic schools including the National College of Chiropractic. Their treatments may include naturopathic remedies, physical therapy devices, or other CAM methods. While still subluxation based, mixers also treat problems associated with both the spine and extremities, including musculoskeletal issues such as pain and decreased range of motion. Mixers describe vertebral subluxations as a form of joint dysfunction or osteoarthritis. Diagnosis is made after ruling out other known disorders and noting general signs of mechanical dysfunction in the spine. They tend to be members of the American Chiropractic Association, and all the major groups in Europe are also in membership of the European Chiropractors Union.
Objective Straight chiropractors  are a recent off-shoot of the traditional straights and are a minority. This group is differentiated from traditional straights mainly by the claims made. While traditional straights claimed that chiropractic adjustments are a plausible treatment for a wide range of diseases, objective straights only focus on the correction of chiropractic vertebral subluxations. Like traditional straights, objective straights typically do not diagnose patient complaints. They also don't refer to other professionals, but do encourage their patients "to see a medical physician if they indicate that they want to be treated for the symptoms they are experiencing or if they would like a medical diagnosis to determine the cause of their symptoms".  Most objective straights limit treatment to spinal adjustments; they tend to be members of the Federation of Straight Chiropractic Organization (FSCO) and the World Chiropractic Alliance (WCA).
Reform chiropractors, also a minority group, are primarily mixers who advocate the use of manipulation as a treatment for osteoarthritis and other musculoskeletal conditions. They do not subscribe to Palmer philosophy or the vertebral subluxation theory. Instead they recommend the use of palpation and manipulation to identify and treat painful joints which may contain adhesions. This group is very similar in practice to mixer chiropractors, though they tend not to use CAMs.