Primary Mis-alignment
When the spine miss-aligns, it does so as a unit. All the segments of the spine lose their proper orientation to the gravitational field. It is the top of the spine involving the joints between the head and first vertebra of the neck (C1), and the joint between C1 and C2 that keeps the spine in its miss-aligned state.
Spinal miss-alignment usually causes the head to rotate on the C1 vertebra and laterally tilt to one side (termed “head tilt”). The C1 vertebra slips to one side, moves off the horizontal plane, and usually rotates in the transverse plane. The lower neck also rotates and forms an acute angle with the C1 plane line. The effect of the 10 – 15 pound head tilting off the center of gravity causes the spine to curve underneath the head. This curving of the spine supports the uneven weight of the head tilting to one side, and brings the eyes level with the horizon. There are neurological factors that maintain the misalignment as well.