The nervous system is the control system of your body. The job of the brain is to monitor, run, and control the functions in your body, and it uses the spinal cord and nerves of the body as its communication lines.
As long as the brain and nervous system are able to communicate with the body without any interference, then the body can function at a higher level.
Your brain is protected by your skull, and the spinal cord is protected by your spine. The spine is composed of twenty-four moving bones called vertebrae, and each vertebra contributes protection of the spinal cord. When a vertebra loses its ability to move properly, or its alignment relative to the other vertebrae is altered, it places abnormal stress on the spinal joints, ligaments, muscles, and discs (cushions between vertebrae).
Between each vertebra, a pair of nerves branches off the spinal cord. These nerves go directly to the muscles in the spine, arms, and legs. The spinal nerves also connect to a major part of the nervous system that controls the function of the internal organs, blood vessels, and glands of the body.
When pressure is applies to these nerves, function is disrupted resulting in pain and numbness to any body part connected to that nerve pathway.
Dr. Chung Ha Suh of the University of Colorado showed that even a small pressure (about the weight of a dime) on a nerve can reduce the function of the nerve by 60 percent and that the nerve will start to degenerate if the pressure is sustained for three hours. (1)
Dr. Bland of the University of Vermont School of Medicine, demonstrated that the removal of nerve pressure in the neck and upper back discs resulted in pain reduction of the lower back. (2)
(1) Dr. Ch.H.Shu, University of Colorado Project, Effects of Compression on Spinal Nerve Roots.
(2) Disorders of the Cervical Spine : Diagnosis and Medical Management by John H. Bland,1987