According to ACA: (American Chiropractic Association)
Chiropractic is a health care profession that focuses on disorders of the musculoskeletal system and the nervous system, and the effects of these disorders on general health. Chiropractic care is used most often to treat neuromusculoskeletal complaints, including but not limited to back pain, neck pain, pain in the joints of the arms or legs, and headaches.
Doctors of Chiropractic – often referred to as chiropractors or chiropractic physicians – practice a drug-free, hands-on approach to health care that includes patient examination, diagnosis and treatment. Chiropractors have broad diagnostic skills and are also trained to recommend therapeutic and rehabilitative exercises, as well as to provide nutritional, dietary and lifestyle counseling.
The most common therapeutic procedure performed by doctors of chiropractic is known as “spinal manipulation,” also called “chiropractic adjustment.” The purpose of manipulation is to restore joint mobility by manually applying a controlled force into joints that have become hypo-mobile (or restricted in their movement) as a result of a tissue injury. Tissue injury can be caused by a single traumatic event, such as improper lifting of a heavy object, or through repetitive stresses, such as sitting in an awkward position with poor spinal posture for an extended period of time. In either case, injured tissues undergo physical and chemical changes that can cause inflammation, pain, and diminished function for the sufferer. Manipulation, or adjustment of the affected joint and tissues, restores mobility, thereby alleviating pain and muscle tightness, and allowing tissues to heal.
A BRIEF HISTORY OF CHIROPRACTIC
The first recorded chiropractic adjustment was performed on September 18, 1895, by Dr. Daniel David Palmer, a Canadian-born teacher and healer. Dr. Palmer was, at the time, studying the cause and effect of disease. His patient was Harvey Lillard, a janitor working in the same building as Dr. Palmer in Davenport, Iowa. Mr. Lillard, who had complained of hearing problems for over 17 years, allowed Dr. Palmer to examine his spine. Dr. Palmer discovered a "lump" on Mr. Lillard's back and suspected that a vertebra might be out of place, which he then repositioned the vertebra with a gentle thrust. After several such treatments, much of Mr. Lillard's hearing was restored.
Since Dr. Palmer's first chiropractic adjustment, the art and science of chiropractic has progressed significantly. Today, advanced diagnostic procedures, sophisticated equipment, scientific research, and the growing acceptance among other health care professionals makes chiropractic a popular health care choice.