Effect of Subluxations
Slight subluxations may exist, because of the adaptation of surrounding parts and the slight play within the intervertebral foramen, without producing noticeable effect. They always, however, evidence a tendency to disease.
The majority of subluxations do produce disease, to some degree, and do so by impinging nerves. Impingement may be either by pressure against a nerve or ganglion or by constriction of a nerve where it passes through an intervertebral foramen; the former occurs in the case of the Cervical sympathetic, the sub-occipital nerves, and the sacral nerves; the latter is the commoner form in Dorsal and Lumbar regions of the spine. Probably the most positive constriction of a nerve which can occur within the body is to be found in rotation of Lumbar vertebrae; the body of the rotated vertebra encroaches upon the inferior nerve on the side opposite to the direction taken by the spinous process.
Either variety of impingement produces disease, morbid structure or function, by irritation of the nerve: light impingement irritates, heavy impingement partially or completely paralyzes, the nerve.