Movement
I have said, but have not sufficiently emphasized the command, that the shoulders must be dropped loosely forward. Let me add that just before the movement is given the head should be allowed to sag downward and the muscles to become relaxed. This movement given with stiff shoulders and upraised head becomes a push.
The desired movement is a throwing movement.
Force is released from both shoulders at once, concentrated at the same instant by a slight shifting forward of the elbows, and strikes the spinous process as one force, which is the resultant of the two meeting at the wrist of contact hand and being united there. The two arms use the contact hand as a passive instrument for driving the vertebra.
The objective point, the distance to which the movement is mentally thrown at the instant of delivery, should be the center of mass of the vertebra, varying according to the section of the spine.
Contact Point
The exact contact point of hand with vertebra varies. If the vertebra is to be moved toward the right the pisiform rests against (not upon) the left side of the spinous; if toward the left and inferior, against the right side and just above, in the notch between it and the next superior process. The rule is to so place hand that the spinous process is between the pisiform and the direction to which movement is given.
On the hand the contact may be said to vary, according to the direction of subluxation and position of adjuster, so as to describe a circle around the pisiform in the course of the various changes of position necessary to the use of this movement. No error could be greater than to attempt to use always the same face of the pisiform and to adapt the position of hands and arms to this end, when any face or aspect of the little bone is equally good with any other.