chiropractic [Gr.,=doing by hand], medical practice based on the theory that all disease results from a disruption of the functions of the nerves. The principal source of interference is thought to be displacement (or subluxation) of vertebrae of the spine, although other areas such as joints and muscle tissue may also be the sites of nerve interference. The method of treatment is by adjustment of displaced vertebrae. The chiropractor seeks to relieve the pressure on the nerves and thereby remove the cause of some specific ailment. Massage and manipulation by hand, exercise, and the application of heat, cold, and light are some of the healing techniques used.

The early chiropractors believed that psychic energy, a force beyond human understanding, flowed from the brain, through the nerves, to all parts of the body and that it was interference with this force that caused disease. In 1953 the theory was revised to state that the health of body tissues is controlled by nerve impulses, and that interference in the nerve impulses causes disease. Chiropractic was introduced in the United States by D. D. Palmer in 1895 and carried on by his son, Bartlett Joshua Palmer. There are institutions for training students in the profession of chiropractic, which has legal recognition in the United States and in many other parts of the world.