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. The most common therapeutic procedure performed by a Chiropractor is known as "spinal manipulation," also called "chiropractic adjustment." The purpose of manipulation is to restore joint mobility by applying a controlled force into joints that have become restricted in their movement often as a result of a tissue injury. Such injuries can be caused by a single traumatic event, such a fall or road traffic accident, 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. The Chiropractic adjustment administered to the affected joint and tissues, restores mobility, thereby alleviating pain and muscle tightness, and allowing tissues to heal.