Subluxation
As has been previously stated by no means all concussions of forces produce subluxation. (All subluxations, however, are produced by concussion of forces.) It may be added that not all subluxations impinge nerves and that when they do not so encroach upon nerve tissue they produce no noticeable effect after the first temporary soreness has disappeared.
Every subluxation, however, evidences a tendency to disease. Once moved from its normal position and the poise and symmetry of the body disturbed, there are influences which tend more readily to affect the same vertebra. The subluxated vertebra is more easily disturbed by jars, strains, etc., than the normal one because such jars are less regularly distributed to all its parts. A reflex muscular tension due to other and more pronounced subluxations and their disease effects may in turn increase the slight deviations throughout the spine, rendering them in their turn capable of producing disease. When the spine or any part of it has lost its perfect regularity disease is made possible, if not a fact at once. The average number of subluxations in each individual is about nine and one-third. Of this number probably not more than one-third (though no accurate figures are available) are actually productive of conditions nameable as disease at any given time. Discrimination between those which do, and those which do not, produce discoverable symptoms in a given case is a matter which requires a nice technical skill and perfect judgment.