the usual number of movable vertebrae, the usual deviation being the
presence of twenty-five, and the extra one being most commonly a
Lumbar. In one case under my observation there were twenty-five movable
vertebrae, apparently thirteen Dorsals according to shape, and only
eleven pairs of ribs posteriorly, two pairs being dichotomous so that
there appeared thirteen pairs anteriorly. Deviations in number occur,
in my experience, about once in five hundred cases.
LANDMARKS
The regional location of vertebrae by means of certain landmarks (so
called) in or near the spine, is a much discussed question in the
profession. Without discussing the various arguments in favor of this
method, chief of which is the _inability of the untrained to count
vertebrae_, let us set forth the principal landmarks used and the facts
in regard to them.
The seventh Cervical, called Vertebra Prominens, is usually considered
a guide to the count. In over three hundred cases examined for that
purpose the seventh Cervical was found to be Vertebra Prominens in
about 65%, the other 35% showing the sixth Cervical or first Dorsal to
be the prominent one. This method is two-thirds as accurate as counting.
The tubercle (Chassaignac’s) of the sixth Cervical transverse is said
to be directly opposite the lower border of the cricoid cartilage and
this is a better guide than the above.
The third Dorsal spinous process is said to be on a level with the root
of the spine of the scapula, and with arms hanging at sides, the upper
angle of the scapula to be on a line between first and second Dorsal
spinous process. This is not at all constant.
The inferior angle of the scapula is said by some writers to be
on a line with the tip of the seventh Dorsal spine. Others locate
it opposite the interspace between seventh and eighth Dorsals.
Still others give it as opposite the eighth Dorsal spine. All are
correct--_sometimes_. In truth, the inferior angle may be opposite any
part of the spine between the sixth and ninth Dorsals. There is nothing
constant about it.
The twelfth rib may be followed to its articulation with the twelfth
Dorsal vertebra. This is a good guide, providing that the rib can be
palpated. The lower margin of the last rib is usually even with the
spinous process of D 12 about one inch and a half from the mid-spinal
line. The humor lies in the fact that the patient upon whom the count
is so difficult as to require this verification is usually obese and
obesity renders the rib impalpable.
The line drawn between the iliac crests falls between the third and
fourth Lumbar spinous processes in about 98% of all cases. _This is our
most reliable landmark._ It is used as described under the Count.
All landmarks except the last two show such variance in different
individuals as to be quite unreliable. The correct method of numbering
spinous processes is the obvious and logical method--_count them_.
The skill and accuracy of touch required for successful counting is
invaluable in determining direction of subluxations.
MENTAL ATTITUDE
In order to secure that absolute concentration without which it is
impossible to appreciate properly those tactile impressions for the
very _reception_ of which such continued practice is necessary, the
hands should leave the spine as little as possible during palpation;
a second person should record subluxations found so that the palpater
need only state, and not write, his conclusions; light pressure on
the spine should always be used, as a heavy pressure desensitizes
nerve-endings in the fingers; and silence should be maintained except
for the necessary statement of points to be recorded.
Palpate as rapidly as is consistent with good work. The more rapid
the palpation, _if concentration is absolute_, the more accurate the
impressions received.
The _end_ and _aim_ of palpation is to determine the means by which
impingement of nerves may be removed with the greatest rapidity and
success. Palpation includes such a study of the vertebral column as
will fix in your mind a clear thought-picture of the impinged nerves
throughout its length.
FINALLY
If you would achieve success in Vertebral Palpation, be persistent.
Spare no labor to acquire that accuracy of detail which distinguishes
the expert from the amateur. You can make of yourself what you will.
There is no limit to the ability which may be acquired. Another may
guide your hands but with _you_ lies your success.
NERVE-TRACING
Definition
Nerve-tracing is that branch of palpation by which the tenderness of
irritated spinal nerves is discovered and their paths demonstrated.
Organ-Tracing
Organ-tracing is that branch of palpation which deals with the
outlining of the boundaries and surface markings of a tender organ or
part.
Palpaters frequently confuse tenderness of one of the parenchymatous
viscera for the tenderness of interlaced and branching nerve filaments,
especially in the abdominal region. The fact that the tender area
takes on the characteristic shape of one of the viscera is conclusive
evidence that an organ, and not nerves, have been traced.
What Nerves Traceable
Any spinal nerve may be traceable for at least a part of its course.
The cranial nerves are made inaccessible to palpation by their
location, except the spinal portion of the spinal accessory and the
terminal portions of the nerves to the face. Likewise the sympathetic
trunks, except perhaps in the neck, are untraceable.
Nerve-tracing is comparatively easy in the upper and lower extremities,
neck and back. The superficial nerves of the scalp are hard to follow
on account of the hair. The superficial nerves of thorax, abdomen, and
pelvis are accessible under the conditions mentioned below; the deep or
visceral branches, never.
Of those 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.
[Illustration: 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 wall
anteriorly. There are, however, some Dorsal and lower Cervical nerve
bundles which pass obliquely downward and outward to innervate back
muscles.
Reference to the section on Spino-Organic Connection will make clear
the tissues supplied by each nerve.
_Slight_ deviations from the usual course of nerves are common;
_marked_ deviations very infrequent.
Use of Fingers
Use second finger of either hand for the palpating finger, choosing the
hand which can be most conveniently used as determined by the position
of patient and the part of the body to be examined. There is no set
rule. Reinforce this second finger by the pressure upon it of the first
and third and, if desired, by pressing thumb against it. (See Fig. 5.)
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
In muscular rheumatism, neuralgia, neuritis, or in case of a local boil
or abscess indicating local disturbance of the trophic influence of
nerves, clear and definite tracings are common. Muscular spasm, such
as wry-neck, usually has a very tender nerve associated. Localized
painful disease of any kind is likely to be associated with a very
definite nerve tenderness, as is the case frequently with appendicitis,
ovaritis, hepatic colic, etc.
The painless disorders, or various disorders of spleen, diaphragm,
heart, lungs, etc., though they be of a very serious nature, seldom
are discoverable by nerve-tracing unless their serous membranes are
involved. Tracings _may_ be made from D 2 or 3 to anterior thoracic
walls in heart or lung disease but are not common.
Any spinal nerve may be traceable at times through at least a part of
its course.
Sources of Error
Several of these have been mentioned, such as the natural
suggestibility of both examiner and patient. Among others are: failure
in the back, thigh, or leg to reach the really tender nerve because of
the interposition of several muscle layers between it and the finger,
ignorance of nerve-paths, failure to apply equal pressure to all parts
of a nerve, application of such heavy pressure that muscle tissue is
bruised and hurt, and failure of full co-operation on the part of the
patient. Let us consider these in turn.
If several muscle layers interpose themselves between the searching
finger and the nerve, it is proper to push aside the intervening
layers, using a twisting and rolling movement until the finger
feels _underneath_ the muscles. This done, and a tender nerve found
underneath several muscle layers, the same amount of overlying tissue
must be pushed aside each time the finger searches for the nerve. Only
exhaustive study of the anatomy of the typical nervous system will
enable the examiner to know exactly at what point a nerve will become
more or less superficial. Unless he does know this it is best to follow
the neutral rule that nerves tend to follow the long axes of ribs and
limbs and to maintain their depth beneath the surface throughout their
course. This statement is too general for accuracy.
Care should be taken that equal pressure be made on all points palpated
on one nerve. If the nerve pass over a bone, _less force_ is needed
to exert the same pressure than if it overlie muscle or other soft
structure. The force used varies constantly as the hand moves from
place to place, according to the density and hardness of the structures
overlying and underlying a nerve.
Sufficiently heavy pressure will elicit tenderness in all except
anaesthetic patients. But if a nerve be irritated it will be tender
without heavy pressure, when the finger really makes a close contact
with it.
If the patient willfully attempts to deceive the palpater,
nerve-tracing might as well be abandoned except in those extreme cases
where the patient will flinch against his will on account of extreme
sensitiveness.
Use of Second Hand
As far as possible, the second hand is placed opposite the tracing hand
and steadily supports the body; its position changes with changes in
the position of the first. If the arm is to be examined it had best be
held away from the body, and the part to be examined held between the
two hands.
Position of Patient
For tracing nerves in the neck, back, and upper extremities, the
patient should sit easily. For lumbar, abdominal, or pelvic tracing,
or for tracing in the lower extremities, have patient lie on side or
back. Do not hesitate to change the position of the patient as often
as is necessary to secure easy access to the part to be examined and
relaxation of the patient’s muscles. Never allow the assumption of a
strained position during tracing; the sensation of cramped muscles may
be confused with sensations of nerve tenderness.
SUBLUXATIONS
Definition
A vertebral subluxation is a displacement, less than a dislocation,
in which the chief element is the partial loss of normal apposition
of the articular surfaces of the subluxated vertebra with those of
the vertebra above or below, or both. Or, Vertebral subluxation is a
permanent partial dislocation.
How Produced
Subluxations are primarily caused by trauma--falls, blows, strains,
etc., being the chief factors. Hereditary weakness in structure of some
part predisposes by rendering that portion more easily displaced.
Subluxations are never hereditary but may be congenital through violent
or instrumental delivery into the world or may _appear_ hereditary
because they occur shortly after birth through the effect of light jars
upon the hereditarily weakened segments of the spinal column.
They are always the result of concussions of forces; never of forces
acting entirely _within_ the organism. They result from the contact of
the body with its environment.
It has been said that muscular action in response to peripheral
irritation may produce subluxation. The laws of reflex action render
this impossible. Given a normally aligned vertebra, and consequently
normal nerves and a normal reflex arc in that segment, the ventral
horn cells respond to a _slight_ peripheral stimulus by exciting
muscular contraction on the _same_ side with the irritation. If the
irritation be sufficiently increased, the response occurs on _both_
sides but most strongly on the side from which the irritation comes.
Greater irritation merely serves to cause greater distribution of the
responsive action. (See any standard physiology on reflex action.) In
no case will the difference between the contractions of muscles on the
two sides be sufficient to displace a normally aligned vertebra. Nature
has provided against that contingency.
Given a subluxated vertebra causing nerve impingement and thus
interruption of the normal action of the reflex arc, irritation may
result in greater contraction upon the _opposite_ side than upon the
side of the irritation. This is an abnormal condition and accounts
for the _increase_ of previously existing subluxations under pain or
peripheral irritation. But in every instance trauma must and does
precede and cause subluxation.
Reaction of Secondary Causes
Once produced, however, a subluxation may not cause noticeable effect
until it has been _increased_ in degree by the reaction of forces
within the body such as poisons, general fever, etc. Thus germs,
dietetic errors, exposure to sudden temperature changes, waste of
energy through abnormal mental activities, as hate, fear, worry, etc.,
or through physical excess--in fact, all the _secondary_ causes of
disease may _appear_ to have produced a subluxation. In fact, they have
merely accentuated that which already existed and have done so through
the muscular contractions which they induced.
General thinning of intervertebral substance through a condition
of disturbed metabolism itself produced through the agency of some
_one_ serious subluxation, may narrow all the foramina and increase
impingement of nerves at any point where a slight subluxation
previously existed. An irritated nerve may become swollen and the nerve
impinged at the foramen.
Law Governing Location