Chiropractic is the largest, non-drug, non-surgical health care profession in the United States with over 21 million visits made to chiropractors every year. Chiropractic treatment is based on the relationship between the muscles, nerves joints of the spine, and the extremities. Chiropractors perform manual treatment of the joints called adjustments, as well as soft-tissue treatment to the muscles, fascia and ligaments to restore normal function. They also use exercise for rehabilitation and sports conditioning, as well as nutritional and other lifestyle advice in a holistic approach to health and healing.
What occurs in the spine and extremities that is treatable with manual techniques? There are three common areas of stress: physical stressors (for example sitting, or sport injuries which cause gradual or acute joint and muscle injury); emotional stressors (unresolved or repetitive emotional reactions which cause reactive muscle tension); and chemical stressors (poor nutrition, pollution which reduce the healing capacity of the body and can also cause reactive muscle and nerve tension). These can cause the heavily innervated joints of the spine and the extremities to lose their normal range of motion and, in turn, change the function of the muscles attached to the spine and the nerves that carry information to and from the spine.
This complex of changes is called a manipulable lesion or joint dysfunction. The dysfunction can affect the health of the entire body. When there is lack of motion in a joint, or too much motion, adhesions and scar tissue can form in the ligaments and capsule of the joint to stabilize it. This can be the first step in developing degenerative joint disease. Adhesions and scar tissue can form in the muscles that attach to the spine or in the extremities, causing muscle weakness, atrophy and pain. Lack of motion can cause inflammation where the nerve roots exit, and can cause pain, numbness and weakness in an extremity, such as sciatica or cervical nerve root syndromes. Tension in the joints and muscles of the upper back and neck can cause both muscular and nerve mediated headaches from the upper cervical spine.
How do adjustments stop this process? There are many types of chiropractic adjustments (over 97 different named techniques). But all techniques seek to remove spinal joint dysfunction and its effects. Chiropractors find areas of abnormal motion through specific palpation and movement tests. Many adjustments apply a “high velocity, low amplitude” force with the doctors’ hands or an instrument.
This can correct the range of motion, muscle and nerve dysfunction as follows: the adjustment can mechanically “break up” restriction in motion in a specific direction to normalize spinal joint function. The adjustment can neurologically release overactive muscles as it affects the “golgi tendon organs” in the muscles. (These golgi tendons are activated with sudden increases in tension, such as the high velocity adjustment. They cause the muscle to relax in response to any sudden increase in tension.)
Finally, there are two types of nerves that innervate the spine and extremity joints: pain-sensitive nerve receptors (“nociceptors”) and motion sensitive receptors (“mechanoreceptors”). By applying motion to the joints through adjustment, the mechanoreceptors are stimulated, which inhibits the nociceptors, thus reducing pain. This also releases reactive muscle tension caused by pain, and the reduced tension normalizes the joint motion. Thus, chiropractic adjustments can restore range of motion, relieve pain, normalize nerve function, and correct the joint dysfunction.