Abstract
The purpose of this study was to obtain a more complete understanding of how two particular adjustment techniques effect forces and moments on the atlas and axis vertebrae. The main objective was to provide a clear and logical mathematical understanding of each technique using basic concepts and principles of physics. In order to meet this objective, emphasis has been placed on sound theoretical argument as it applies to this problem.A generalized static analysis of two particular techniques was performed: (I) the side posture method and (II) the knee-chest method. It is very difficult to apply forces that are primarily aligned in the direction of any fulcrum moment, and therefore rotational motion. Thus, static analysis of Technique I revealed an inherent inefficiency in this approach.The primary reason Technique II was favorable (from a mathematical standpoint) was that it allowed application of forces at large angles relative to all three principle axes of rotation. This was shown to maximize efficiency, producing significant moments about the dens for all rotational degrees of freedom.