Apply the tip of the palpating finger to the nerve with a motion such that it crosses the path of the nerve at right angles back and forth. Meanwhile the probable path of the nerve must be kept in mind. As the finger crosses the nerve-path it makes steady and even pressure upon any structures passing beneath it. The motion of the hand is almost a rolling motion, the finger tip probing, as it were, for a tender spot. Tenderness--How Recognized The irritated condition of the nerve which has thus been rolled beneath the finger may be recognized in one of three ways; the patient may involuntarily flinch, betraying the hurt; or he may inform the palpater of the hurt; or the swollen, cord-like nerve may be felt. The two former are the reliable guides, while the latter is only occasionally possible. In children and in feeble-minded, insane, or mute adults, the first mentioned method must be relied upon entirely. Muscular contraction is the unconscious or reflex response to pain and often occurs independently of the intelligence or state of mind of the subject. Of all the three methods the one most commonly relied upon is the second--the statements of the patient. Instruction to Patient The patient should be informed of your intentions when palpation is begun and should be asked to answer every time you apply your finger, saying, “Yes,” if the spot is tender and, “No,” if not. He should speak promptly each time so as to avoid self-deception which might come with reasoning upon his sensations. Occasionally vary the steady rhythm of your movements by omitting one and note if the patient responds mechanically when you do not press. At times during the tracing, it is well to depart from the probable nerve-path and to touch again a point marked as tender, to see if the patient’s information may be relied upon. Whenever you leave the nerve-path his answer should be, “No,” immediately changing to, “Yes,” when you re-cross the tender line. Marking Tender Points At each tender point noted a small mark should be made with an eye-brow pencil or other grease-paint, which leaves a distinct but easily removable mark. These tender points should be noted and marked at intervals of about an inch. Connecting Line When the entire nerve-path has been traversed in this way, draw a line with the eye-brow pencil, passing through all the marks indicating points of tenderness. This line should be a sufficiently accurate rough outline of the nerve-path to make clear the spinal connection with the diseased area. The significance of this connection will be better understood when the section on Spino-Organic Connection has been studied. [Illustration: Fig. 6. Anterior half of completed nerve tracing.] Common Findings