Technic and Practice of Chiropractic. Joy Maxwell Loban
nerves mentioned as traceable, only such as are irritated and consequently swollen and tender, can be followed. If a nerve is very heavily impinged, especially if the impingement be chronic, it is partially or wholly paralyzed and not traceable. If the heavy impingement be acute, or if there be a light impingement serving as a mechanical irritant, nerve-tracing is a real aid to diagnosis.
Proportion of Cases with Traceable Nerves
About one-half of all the cases which visit Chiropractors for adjustment are susceptible of nerve-tracing. In the remaining half it is absolutely impossible to acquire any information in this way. Of the half who are at all susceptible, it is possible in perhaps four-fifths of all cases to secure some accurate or reliable information.
The patient in whom all accessible nerves seem tender to light palpation is hyperesthetic and unavailable for tracing.
In the usual case one or two nerves will be found easily traceable, while the rest exhibit no tenderness on pressure. Such a case furnishes the most reliable information securable by this method and the tender nerves may be considered as lightly or acutely impinged.
Preconception of Nerves Essential
Knowledge of the anatomy of the nervous system is a part of the necessary equipment of the Chiropractor who would trace nerves and this knowledge should be so thorough as to enable the palpater to recognize each tender line found as an anatomically described nerve-path or an error on his part. The examiner must know the paths of all nerves and be able to predict from the first tender points discovered the probable course which the tenderness will follow, so as to direct his search along that probable path.
He must be able to detect unconscious deception on the part of the patient through his knowledge of the anatomical impossibility of the apparent tracing. For instance, if for any reason he may appear to have traced a nerve upward beside the spinal column from D 10 to the eye by way of the vertex, he must know that this is an illusion—because such nerves do not exist and cannot be anatomically demonstrated—or accept the well merited ridicule of any educated person who discovers his absurdity.
Because of the difficulty of determining whether the tender structure found be muscle, nerve, or viscus, and because of the natural suggestibility of both palpater and patient, nerve-tracing cannot be so reliable a guide to nerve-paths as is dissection. It should not be necessary to state this obvious truth but the calm acceptance, by many, of the weird conclusions based upon a belief in the infallibility of nerve-tracing testifies that it is necessary.
Nerve-tracing is valuable only where the nerve-path outlined as being tender corresponds to the known path of some nerve.
Suggestion
Paradoxically, knowledge of nerve-paths may lead to error. By the law of expectancy, we are prone to find what we look for and if we hold too strongly to the belief that because we have found one or two points of tenderness we must find a series of points extending along a mentally pictured nerve-path, we may search until we falsely believe that we have found this series.
Likewise the patient, having been carefully informed as to the manner of procedure and knowing what we expect to discover, may unconsciously deceive us by feeling tenderness in response to suggestion, where no real impingement exists.
Place in Diagnosis
The value of nerve-tracing in diagnosis has been much overestimated by many, though the tendency of the profession seems to be toward rationalism along that line.
Whereas, in palpation of the spine every real subluxation gives evidence of disease, or tendency to disease, while every normally aligned pair of vertebrae furnish proof that no disease can exist in the area of distribution of the nerve emerging between them, nerve-tracing is much less reliable. If the tender nerve be traceable to a vertebral subluxation it may be taken as additional evidence that the effect of that subluxation is disease, rather than tendency to disease, truly an important distinction, but scarcely broad enough to support a diagnosis without aid.
The absence of tenderness from nerves does not negative a disease in any instance, whereas the absence of subluxation does. Like all other expedients for the selection of vertebrae for adjustment without admitting the necessity for first acquiring much skill by much labor, nerve-tracing has a great weakness. Only irritated nerves are tender and the effects of subluxation may be either irritation or paralysis.
If accurately done, sources of error carefully eliminated, and the results of nerve-tracing found to correspond with the condition of the spine and the other symptoms, this method of demonstrating to the patient the connection between the vertebrae and the diseased region of his body is valuable. It aids in convincing him of the validity of the Chiropractic theory.
TECHNIC OF NERVE TRACING
Where to Begin
The palpater, having made his vertebral palpation, may begin at some point in the body indicated by the symptoms as diseased and, finding tenderness, follow the path of a nerve back to the spinal column where the nerve may be fairly presumed to enter the intervertebral foramen.
Or he may use his palpation record as a guide and follow the tender nerves outward to their periphery. This is the better method.
Fig. 5. Technic of nerve tracing, showing position of fingers and marking of tender points.
Palpation as Guide
When palpation has been made, remember that the impinged nerve is usually found on the side opposite to the direction of the spinous process in its departure from the median line. With a left subluxation the tenderness is usually, though not always, on the right side. If in the Lumbar, and the subluxation a rotation, the impinged nerve will be found below the transverse process of the subluxated vertebra. In the Cervical and Dorsal regions the tender nerve is usually below, but may be either above or below, the transverse of the subluxated one.
Examine the nerves having exit from the foramina of each subluxated vertebra in turn from above downward. When a tender point is found about an inch from the mid-spinal line, attempt to follow the nerve and palpate until it has been traced as completely as possible.
Where to Expect Tenderness
The region immediately surrounding the spinous process of the subluxated vertebra may be tender because of impingement of the axons of the posterior primary division of that spinal nerve which emerges below the vertebra. Such tenderness is more common with anterior subluxations than with others. It is not to be confused with the soreness which often appears after adjustment and is due to bruising or straining of the tissues.
Nerve tenderness may be discovered at a little distance from the mid-spinal line and at a level slightly lower than the emergence of the nerve. If a nerve is irritated, the finger inserted between the ribs near their articulation with the transverse processes will elicit tenderness. The discovery of tender points along the spine is the most important part of nerve-tracing.
Nerve-Paths
Detailed description of the paths of all the spinal nerves may be studied from any standard work on anatomy and will not be included here, but it may be well to remind the reader of certain general tendencies.
The spinal nerves do not cross the median line in front except perhaps fine interlacing fibres.
In the Dorsal region the nerves are usually found following the interspaces until the lower ones debauch upon the abdominal