An epiphyseal plate may be absent, having been broken off by trauma and absorbed. This can be discovered by noting the too-wide space between apparently adjacent vertebrae, and careful palpation will disclose the apparently much anterior vertebra, an appearance not borne out by the position of the transverses. When an epiphysis is absent a patient has a somewhat weak back from lack of muscular attachment.
Lipoma, or the heavy cicatrix following a burn or carbuncle, may render palpation of two or three vertebrae impossible. In such a case only the palpater’s experience and his knowledge of the characteristics of various vertebrae will enable him accurately to number the remainder.
Patients with much adipose tissue may require palpating in several positions in order to permit certainty.
A deep third Cervical which is absolutely impalpable may mislead one, but a careful count which shows one vertebra overlooked indicates the necessity for a careful re-examination of the Cervicals, by which the gap at the third at least may be appreciated. If the Axis is very much inferior the third is especially likely to be overlooked.
Anomalous cases have been found in which there were more or less than 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