Is a quick, but fairly gentle, movement of both hands together, so that the head is rocked still further backward at the instant an anteriorly directed force is applied to the prominent transverse. The result is rotation of the vertebra—unless there be a loose articulation in the Cervicals which gives way under the force applied to the head.
THE EDGE CONTACT
(“Point 2 Contact”—“Knife Move.”)
Name
This movement has various names. The name “Point 2 Contact” is handed down from the days when Palmer used three contact points and three moves and designated the middle of the ulnar side of the fifth metacarpal bone as “Point 2.” The name “Edge Contact” was applied later, during the improvements in its technic when the hooking of the thumbs stiffened its efficiency and made it very valuable. It has since been rediscovered (though in constant use) and re-named “Knife Move.”
Uses
A movement which uses the spinous process as a lever and is applicable to D 2, 3, or 4, and to any Dorsal or Lumbar from D 8 down, when posterior, postero-superior, or postero-inferior. It does not correct rotation except insofar as the shape of articular processes may aid an anteriorly directed move in rotating the vertebra.
Some Chiropractors have used the Edge Contact in the Cervicals but this is always improper, as it is practically impossible in some, and difficult in all, cases to cover only one spinous process when the head is resting on its side.
Fig. 27. The edge contact in Lumbar region.