Spinal Manipulative Therapy
Spinal manipulative therapy uses various techniques to apply force to an area of the spine or to a joint. Massage or mobilization of soft tissue is used in techniques such as myofascial trigger point therapy, cross-friction massage, active release therapy and muscle stripping. Mechanical traction or the use of external resistance on an area of the spine or on an extremity may be used in certain people.
There are a number of traditional and scientific theories about the mechanism of action and potential health benefits of chiropractic and spinal manipulative therapy. However, the underlying effects of these therapies on the body are largely unknown.
Traditional hypotheses suggest that changes in normal relationships between the bones of the spine (vertebral bodies) or joints can result in health problems and that manipulation of these areas may correct these changes and improve function. There are more recent theories that nerve damage or compression, muscle spasm, soft-tissue adhesions or release of toxic chemicals from damaged soft tissues can be caused by abnormal spine or joint positioning, which can be improved with manipulation. Scientific research is limited in these areas.
Scientific studies in animals and humans report that abnormal positioning of the spine can alter the function of nerves coming from the spine and may alter heart rate and blood pressure. It is controversial whether spinal manipulative therapy affects the release of chemicals that influence pain and pleasure sensations, such as substance P and endorphins.