A good illustration of the value of speed may be taken from a pile of stakes bound together by a cord. If a man with a hammer desires to remove the center stake of the group, and attempts to do so with a slow pushing movement, the result is a change of position of many stakes, which adhere to the center stake and to each other. If, on the contrary, he strikes a sharp, quick blow with his hammer, meeting squarely the center of balance of the one stake, it will fly straight from its position leaving the others unmoved. This is exactly what we desire to accomplish with an adjustment. By the speed of the movement we expect to move _one_ vertebra before adhesion or the contraction of muscles or inelasticity of ligaments can diffuse the force. Close Contact In order to accomplish the transmitted shock it would seem wisest, at first thought, to draw back the hand and strike the vertebra sharply. On the contrary, it has been found advisable to place the hand carefully in _close_ and _immediate contact_ with the vertebra to be adjusted. Nature herself shows us the way in the delicate shock-transmitting mechanism of the tympanum. Also the hand of the adjuster will cover much more than merely the spinous or transverse process which is used as a lever and to which it is desired to transmit the shock, unless carefully placed so that only a _small portion_ is in contact; by such a contact diffusion of the shock is prevented and its efficiency within a limited area is increased. A carpenter wishing to countersink a nail places in contact with the nail head a small instrument called a countersink, which he then strikes sharply with a hammer. The contact hand of the adjuster represents the countersink and is used by the two arms as a passive instrument for transmitting shock. The close contact of the hand, which remains passive, renders the adjustment much less painful to the patient than it would otherwise be, and one of the prime objects in the mind of the adjuster should be the minimizing of pain inflicted, by any means which does not lessen the resulting benefit. Also any drawing back of the hand before the movement warns the patient and tends to induce involuntary muscular contraction which interferes with adjustment. Relaxation In an adjustment it is necessary to overcome two kinds of resistance--the passive resistance of inertia, of ligaments, or of superincumbent weight, and the active resistance of muscular contraction. It is important that both forms be minimized. The first may be lessened through the position of the patient’s body; he is placed so that the vertebra to be adjusted is in the freest possible position. The second is reduced to the least possible quantity, amounting to no more than muscle tonus, by using two methods: (a) Oral Suggestion, and (b) Muscular Suggestion. Oral Suggestion