To move an Atlas so disposed that its one side is posterior while the whole vertebra is laterally displaced in the same direction; to move, for instance, an Atlas R. P.
Have patient lying on back in position C with head projecting beyond bench and supported by adjuster’s knee.
Placing of Hands
Place the first three fingers of one hand under the most laterally prominent transverse so as to hold it firm, first placing the first finger carefully just behind and against the end of that transverse and then reinforcing it with the second and third fingers, slightly tensed, and resting their tips on the lamina close underneath the occipital bone.
Next place the other hand so that the thumb rests firmly upon the patient’s jaw and the first finger extends backward along the lower margin of the occipital bone.
To complete the position rotate the head gently toward the side of the laterally prominent Atlas, until it rests, face toward the side, and is supported by the three fingers of the one hand and the heel and wrist of the same hand. It will be noted that when the head is rotated the first finger of supporting hand slips to a position directly upon the tip of the transverse process and the other two take its place against the posterior aspect of the tip of the transverse. The Atlas now rests with its intertransverse line almost vertically upward from supporting fingers, which hold it against further rotation.
Movement
When the neck muscles have been thoroughly relaxed by slight and gentle movement, throw the upper elbow sharply away from your body, which has the effect of transmitting force through the thumb to the jaw and sharply rotating the head still further, loosening its articulation with the now firmly held Atlas. The condyloid joints thus loosened tend to settle into their proper relations, the weight of the head causing it to slip downward—laterally upon the Atlas.