Essentials of Osteopathy
Isabel M. Davenport, M.D., D.O.



    In arranging this classification of nerve centers and landmarks for correspondence students I do not claim anything original or unique.  "There is nothing new under the sun" is as applicable to these nerve centers and their locations as to anything else under the sun, and yet, with one exception (that most excellent and most completely arranged work of Charles Hazzard known as Principles of Osteopathy), there is no satisfactory arrangement made of these centers and landmarks by which the student may know where to look for the origin or termination of a nerve, or where to treat for effect upon the sympathetic system etc.  And because I have so many questions upon this point and along this line I have made this crude little arrangement and hope it will be received in the spirit in which it is written -- not as an attempt at authorship, but merely as a convenient aid to the study of Osteopathy.

    I have not attempted to give treatment in this little work.  The references I have made to it are merely incidental.  Inasmuch as anatomy, physiology and all of the subjects referred to are not original with any author I have quoted largely from others, especially Hazzard, and have done them the honor of naming them with every quotation in order that they may receive all credit due them for their research and knowledge.  If I have been able to arrange the nerve centers and landmarks in such a way as to be helpful to the student of Osteopathy I am content.

Chicago, Ill., July 1st, 1903.



    Assuming that the student has become thoroughly acquainted with the anatomy of the human body, as must be the case if he desires to be a thorough osteopath, I shall not go into detail, but give in the most simple and plainest manner possible the subject matter of this lesson.

    To make it plain let us consider the central nervous system, or the brain and spinal cord, as the dynamo which generates the power, whatever it may be, that runs this most wonderful of all machines, the human body.  Now this dynamo is made up of cells which for a simile you may liken to the cells of the honeycomb filled with honey.  Between these tiny cells is the stroma or honeycomb made up of fibrous tissue which surrounds the cell and then forks off into long strings or fibers.  The nerve force is generated in the honey or protoplasm contained in these cells and is carried out to the muscles, skin and internal organs, etc., by the prolongations or strings of honeycomb.  In fact, the nerve fibers.  Running along with these nerve fibers are arteries and veins, and to reinforce the dynamo, at some distance, are small batteries or stations known as ganglion.  Now, as you already know, there are two systems of nerves, known as the spinal and the sympathetic.  Each has its origin in the brain and is reinforced and aided by the spinal cord and nervous ganglion.  The brain and spinal cord are encased in heavy boxes of bone for protection.  These boxes (the skull and spinal column) are made up of many small blocks of bone joined together by ligaments and give attachment for many muscles, all of which aid in keeping them in place if in their normal condition, and in displacing them if not in normal condition, but of this I shall speak later.  The nerves from the brain make their exit through small openings or foramina upon the face and in the neck.  Those from the spinal cord emerge through the foramina between the vertebrae or small blocks of bone, which make up the spinal column, and are distributed to the muscles and skin.  The sympathetic nervous system has its origin in the brain and forms two chains which are reinforced at frequent intervals by ganglia, giving the appearance of numerous strings connected at certain distances by a large bead.  These chains pass down on the inside of the spinal column and are finally connected by the ganglion impar in front of the coccyx or terminal bone of the spinal column.  Now, during the whole course of these two chains or systems of nerves, i.e., cerebro-spinal and sympathetic, they are connected by communicating fibers known as Rami communicantes, Rami efferentes and associate fibers, as the case may be.  So in reality it is one whole nerve system, and what affects one, no matter how remote, will in time affect the other.

    The nerve fibers of the sympathetic system supply or carry nerve force to the internal organs, the in-voluntary muscles (or those which act without our volition or knowledge), to the walls of the blood vessels, the brain and the secretary cells of the glands.

    Now the osteopathic theory is that so long as this power which runs the machine is uninterrupted and allowed to go on in its normal course the machine will run until worn out, which, according to the Bible, is three score years and ten.  Disease is an accident due to some obstruction to the normal flow or course of the vital fluids, namely, nerve force, circulation of the blood, lymph, chyle, bile and all secretions or excretions of the body.

    This obstruction. may be due to slight or great displacements of the bones.  It may be a slight slipping to one side or to the front or back, or upward or downward of the bones at their articulations or joints.  For instance, the vertebral column is made up, as I have told you, of small blocks of bone piled one upon the other.  The nerves and blood vessels emerge from small openings between these vertebrae.  Now suppose the muscles which are attached to these little blocks of bones, or the muscle which is attached to one side of one, contracts, either from external stimulation, such as a blow, or from cold, is it not reasonable to suppose that this contracted muscle may pull that little block of bone over until it encroaches upon the nerves and blood vessels which emerge from beneath it?  Or suppose the ligaments attaching this little block of bone to its neighbor or to the rib which adjoins it becomes relaxed, cannot you see how easy it would be for the rib, let us say, to drop down into the notch and impinge the nerve or blood supply?  Or let us suppose what is even more common -- a simple contraction of the muscles about the blood and nerve supply to a part, when we think of the power of one small muscle we can readily conceive how they may contract down upon the tender nerves and blood vessels and impede, if not entirely obstruct, circulation.  Or again take an area where the blood vessels have been injured.  In this case the little plates which form the walls of the vessel separate and the serum or watery constituents of the blood seep through into surrounding tissue (i.e., inflammatory exudate) and often forms a hard fibrous mass which by pressure interferes with circulation.  When you sum it up, a true definition of perfect health is a perfect circulation of the vital fluids.  True, many diseases are due to germs or to absorption of poisonous gases, but if one lives much in the open air and thus keeps a good quality of blood, and this life-giving fluid is freely circulated to all the tissues these will be so well fortified they can and do resist any and all germs or other poisons with which they naturally come in contact and no harm is done.  But having these germs always with us, as it were, then given a stagnate circulation which allows the vitiated and poisonous venous blood to remain too long in a part, you have tissues which are poorly nourished and too weak to resist, and so these poisonous gases and deadly germs are allowed to enter the system and the result is disease; and if you cannot remove the obstruction, thus establishing a normal circulation (not of blood alone, remember, but of nerve force and all vital fluids) then death all too soon perhaps.

    And so, according to the osteopathic theory, the osteopathic practitioner should be the machinist who easily and readily recognizes and corrects the cause of obstruction to normal circulation and in so doing he naturally goes first (as near as possible) to the origin of the nerve supply, the spine, for a cause and for this reason the spine will be your first point for examination of the case before you, and I shall next give you the usual manner of examining a patient for osteopathic diagnosis and treatment.



    When a patient presents himself to you for treatment always make a thorough examination before attempting a diagnosis which, of course, must be made before you can treat intelligently.  Listen attentively to the patient's "tale of woe," for besides being a consolation to him it may aid you some, though you must strictly avoid making a diagnosis from symptoms and look for lesions.  However, it is a good plan to talk with the patient, making him or her feel less restrained and thus helping them to relax and feel easy under your treatment.  Then, too, you may learn something of the natural physical tendencies as well as the habits of the patient, and hence will know how to advise then as to care, diet, dressing, bathing, etc.  You may also learn, perhaps, whether any deformity you may find is congenital or acquired.

    I keep a number of suits of pajamas (jackets and trousers) made of washable material, loose and adjustable to almost any sized-person, in my office, and after talking with the patient for a few minutes I have them shown to the operating room and told to remove all their clothing except the underwear and to don one of the pajama suits, giving them instructions to touch the bell when ready for treatment.  In my operating room I have a table six feet in length, two feet high and two feet wide.  The frame and legs are of oak strongly put together and the top is stuffed with excelsior, covered with hair and upholstered in leather.  On this I place a small pillow with a clean towel over it for each patient, and if the room is at all cool a light robe or blanket.  Then when your patient is ready have him lie at full length upon the table on his side, and beginning with the neck make a thorough examination all the way down the spine for abnormal variations in the spinal column -- as to position of the vertebrae one to another; for hard, contracted muscles, both superficial and deep, which will feel hard and cordy under your fingers; for sore or tender spots, and for variations in the normal curves of the spine.  Also note the position of the heads of the ribs.  After going down one side carefully have the patient turn over and examine the opposite side in the same way; then have the patient sit up on the side of the table or on a stool and examine the curves of the spine.  See whether the neck is straight and after placing him on his feet look to his hips and shoulders whether they are even or one is higher or lower than the other.  I also, in treating, notice these things when the patient is lying at full length in the dorsal position.  Note also the complexion and the eyes -- whether pupils are dilated, contracted or even, whether the eye is abnormal in any way.  Note the face -- whether the lines are symmetrical or not, whether the expression is one of distress or is pleasant, happy and placid, intelligent or vacant, etc.  When examination is completed have the patient resume the prone position upon his side on the table for treatment.  Before going into treatment, which is not my purpose here, we will become familiar with the location of the spinal and sympathetic nerve centers, as we call them.



    The origin of the eight cervical nerves corresponds to the interval between the sixth cervical spine.

    The origin of the first dorsal nerves corresponds to the interval between the fourth and eleventh dorsal spines.

    The origin of the five sacral nerves corresponds to the last dorsal and first lumbar spines.

    Landmarks along the spine.  Holden instances a median furrow caused by the prominence of the erectors spinae which extends along the spine as far as the interval between the fifth lumbar vertebra and the sacrum.  Hollows upon the surface correspond generally to prominences of the skeleton and vice versa.  This is on account of the attachments by tendons to prominent skeletal points.  Hazzard says sharp friction will redden the spines of the vertebrae so that they can be counted and one can notice whether they are in place or not.

    The level of the third dorsal spine is the level of the root of the spine.

    The level of the seventh dorsal spine corresponds to the inferior angle of the scapula.

    The level of the twelfth dorsal spine corresponds to the head of the last rib.

    The level of the third intercostal space corresponds with the root of the spine of the scapula.

    The level of the third dorsal spine corresponds with the third intercostal space.

    The level of the third intercostal space corresponds with the level of the right and left bronchi, the right being near the posterior chest wall.

    The following is a convenient method for ascertaining the position of the twelfth dorsal spine: Have patient fold his arms and lean forward, thus bringing the spines of the vertebrae out prominently, then the lower border of the trapezium muscle can be traced to the twelfth dorsal spine.

    The kidney is best reached by pressure below the level of the last rib at the outer edge of the erector spine.

    The tip of the crest of the ilium is about the level of the spine of the fourth lumbar vertebra.

    The ilio-costal space extends from the lower border of the twelfth rib to the crest of the ilium, varying in width from the breadth of the finger to that of the hand.

    In the depression below the occiput are found the edge of the trapezius muscle and the upper end of the ligamentum nuchae.

    The second cervical spine is forked and rather prominent.  The third, fourth and fifth cervical spines are not usually made out, as they recede anteriorly from the surface.  The sixth and seventh (prominens) are prominent.

    The spines of the dorsal vertebrae correspond with the heads of the ribs next below, e. g. the fourth dorsal spine with the head of the fifth rib.  But the eleventh and twelfth dorsal spines correspond with the head of those ribs.  The following landmarks from Holden may also be useful before going further in the examination of the body.


    Opposite seventh cervical spine, apex of angle of bifurcation of trachea.

    Opposite fourth dorsal spine, aortic arch ends; upper level of heart.

    Opposite eighth dorsal spine, lower level of heart; central tendon of diaphragm.

    Opposite ninth dorsal spine, oesophagus and vena cava perforate diaphragm.

    Opposite tenth dorsal spine, lower edge of lung; liver comes to the surface posteriorly; cardiac orifice of stomach.

    Opposite eleventh dorsal spine, lower edge of spleen; suprarenal capsule.

    Opposite twelfth dorsal spine, lowest part of pleura; aorta perforates diaphragm pylorus.

    Opposite first lumbar spine, renal artery; pelvis of kidney.

    Opposite second lumbar spine, termination of spinal cord; pancreas; duodenum just below; receptaculum chyli.

    Opposite third lumbar spine, umbilicus; lower border of kidneys.

    Opposite fourth lumbar spine, division 'of aorta; highest part of ilium.

    Angle of bifurcation of trachea is in some cases opposite the fourth dorsal spine.  This angle corresponds in front with the junction of the first and second parts of the sternum.



    The peculiar vertebrae are the second, sixth and seventh cervical, the twelfth dorsal and the fifth lumbar.

    The second cervical vertebra is somewhat prominent and is bifid.  The sixth and seventh cervical become more prominent than any others in that region, especially the seventh, which is called the vertebra prominens by Gray.

    The twelfth dorsal spinous process is flatter and makes a gap or break between the eleventh dorsal and the first lumbar which can be readily felt by the examining hand and may be taken for one of those abnormal so-called breaks in the spine from a normal separation in the vertebrae.  There is also a break between the spine of the fifth lumbar and the crest of the sacrum.

    The transverse processes of the atlas can be easily distinguished between the mastoid process and the angle of the inferior maxillary bone.  They should be located midway between these points.  Sometimes you will find the transverse processes of this vertebra too far forward and making pressure on the carotid artery, causing headache and eye troubles.  You may also find one process too far forward and the other too far back, which shows the vertebra is twisted.

    The ligamentum nuchae, which is attached to the occipital protuberance and to the spinous processes of all the cervical vertebrae to the seventh, sometimes becomes tense and contracted, causing headache and discomfort at the back of the neck.  These symptoms are often relieved by a thorough stretching of this ligament.

    By turning the head to one side you may bring into prominence the articular processes of the vertebrae in the neck, and then tell whether they are in line or in normal position.  If you find sore spots along the spine they denote either a slipping of the vertebrae or contracted tendons or muscles which make pressure upon the spinal nerves at their exit.

    The ligaments and tissues covering the spine may thicken and fill in the normal curves, causing what Hazzard calls a "smooth spinal column" in distinction from the condition known as spinal curvature.



    Third cervical vertebra, middle of neck.  Above, manipulate upward; below, manipulate downward.

    Third, fourth and fifth cervical, origin of the phrenic-hiccoughs.

    Third, fourth, fifth and sixth vasomotors.  The superior cervical ganglion is connected with the first four cervical nerves lying opposite the second and third cervical vertebrae.  The middle cervical ganglion is connected with the fifth and sixth cervical nerves lying opposite the sixth and seventh cervical vertebrae.

    The point between the first and second dorsal vertebrae, the center for the lungs.

    First rib for the heart.

    Between second and third dorsal, ciliary center and recti of eyeball.

    Between fourth and fifth dorsal on the right side for the stomach center, on the left, pneumogastric for the pyloric orifice.

    Fifth and sixth dorsal, vasomotors to the arm.

    Fifth, sixth, seventh and eighth dorsal, great splanchnics.

    Eighth dorsal center for chills.

    Ninth, tenth and eleventh dorsal, small splanchnics.

    Twelfth dorsal, smallest splanchnic.

    From a point between the seventh cervical and the first dorsal to a point between the eighth and ninth dorsal branches to pulmonary plexus.  The posterior pulmonary plexus connects with the second, third and fourth ganglia of the sympathetic. The anterior pulmonary plexus is from the pneumogastric and sympathetics.  "Vasomotors to the lungs have been found in the dog from the second to the seventh dorsal.  This corresponds to the centers upon which we work in man to reach the lungs."

    Second lumbar vertebra center for parturition, micturition, defecation.

    Third lumbar coeliac axis, point between fourth and fifth lumbar vertebra, defecation.

    Fifth lumbar, center for hypogastric plexus.

    From a point between the second and third sacral to the point between the fourth and fifth sacral, center for the neck of the bladder.

    Fourth sacral, center to relax vagina.

    Fourth sacral sphincter ani (the latter two are spinal branches).

    "The term 'cervical brain' has been applied by Dr. Still to the region lying between the first cervical vertebra and the fourth dorsal vertebra; the term 'abdominal brain' has been applied by him to the region lying between the first dorsal and the third lumbar vertebra; 'pelvic brain,' to that region lying between the tenth dorsal and fifth lumbar vertebra."

    Other centers of the sympathetic are as follows:

    Sensation, atlas to the fourth dorsal; nutrition, sixth dorsal to coccyx.  These centers are spoken of by Dr. Still.

    Centers in the medulla as follows:

    Cough, sneeze, vomit, respiration, salivation, phonation, and deglutition venal center, center for spasms.

    Vasomotor centers; medulla, second to sixth dorsal, fifth lumbar.

    Cilio-spinal center, fourth cervical to the second or fourth dorsal.

    Heart center, in the corpora striata first rib; first, second, third, fourth and fifth dorsal vertebra.

    Crevix uteri, ninth dorsal.

    Blood supply to ovaries, eleventh dorsal.

    Uterus, second lumbar, second and third sacral vertebrae, also hypogastric plexus by the lower dorsal and fourth upper lumbar nerves and through the splanchnics.

    "Vasomotors of the head: The eye, ear, salivary glands, tongue, brain, etc., are all reached at the superior cervical ganglion.  Here also a general vasomotor effect to the body is claimed."

    Vasoconstrictors for the head are said to exist at the fifth and sixth dorsal vertebra.  Stimulation of the superior cervical ganglion has a vasoconstrictor effect upon the vessels of the retina, probably through its ascending branch and its connection with the fifth nerve.

    The lungs, second to seventh dorsal vertebra..

    Small intestine, above first lumbar.

    Large intestine, first to fourth lumbar.

    Liver, the splanchnics, vagi, and inferior cervical ganglion.

    Kidneys, the sixth dorsal, second lumbar, renal splanchnics and superior cervical ganglion.

    Spleen, splanchnics on the left side, eighth to twelfth dorsal.

    Lower limbs, second dorsal down.

    Circulation, superficial fascia (the second dorsal for the upper part of the body, the fifth lumbar for the lower part).

    Valves of the heart, second to fourth dorsal.

    Rhythm of the heart, third and fourth cervical.

    The genito-spinal center and lower hypogastric plexus and plexus to the intestinal canal, bladder and vasa deferentia at the fourth and fifth lumbar.

    Bowels (peristalsis) ninth, tenth and especially the eleventh dorsal.

    Larynx first, second and third cervical.



    The Osteopath works from several standpoints, first with a view to reducing any dislocations of bone or of the organs which may exist; second, to relax muscles; third, to relax or replace tendons; fourth, to stimulate or desensitize nerve, as the case may be.

    The physiologists tell us that nerves may be stimulated by mechanical irritation and that a sedative effect may be obtained by pressure or inhibition, and by a system of experiments and close observation the Osteopaths have found that by stimulating or desensitizing the spinal nerves in certain locations they get an unfailing result through the sympathetic nerves upon the parts which they supply; hence these osteopathic sympathetic nerve centers are of the utmost importance to the student of Osteopathy.  I give them entire according to Hazzard.

    As I have told you, the principal point for osteopathic examination is the spine because it with the brain is the central nervous system.  All nerve force emanates from here.  If you cut off the nerve supply you have a dead or useless part; if you cut off or stop the entire nerve force of the body you have death of the body.  It means life.  And so if, for example, a patient gives symptoms of stomach trouble you look for any pressure on or interference with the sympathetics at the fourth and fifth dorsal, and you will find tenderness, if not soreness, in this locality, upon pressure; also, as a rule, over the pneumogastric in the neck. The interference here with nerve and blood supply to the stomach causes an imperfect action there.  Digestion is not carried on to completion because there is not a sufficient amount of blood brought to the part to supply the necessary amount of gastric juice.  The nerve force, also, is lessened, both to the walls of the stomach and to the walls of the blood vessels.  Because of this incomplete digestion there is fermentation and formation of gases, which distend and inflame the stomach, causing irritation to and pressure upon the end nerves; and this irritation or soreness is carried back to the center or origin, and is transmitted by the sensory branch of the spinal nerves to the tissues and muscles about this center and they with the nerves themselves become irritable or sore.  This is illustrated in paralysis.  You will always find the nerves and muscles very sore and painful to pressure in a paralyzed limb, and if you follow the nerves which supply that paralyzed member back to their exit from the spine you will find a very sore point there.  Of course you must determine the cause and treat to remove it.  It may be due to a slight slipping of the vertebrae, it may be due to a displaced rib, it may be due to a slipped or contracted tendon, it may come from pressure of exudate and local congestion, or it may arise from a contracted condition of the entire muscular system, especially of the deep muscles "the multifidious spinae." In many cases you will not be able to distinguish a marked lesion.  In that case treat to relax muscles, to stimulate nerves and to increase circulation.

    On the other hand you may have an irritable condition of the nerves themselves -- the brakes, as it were, are off.  The stimulation in the cells of the brain or spinal cord is too great or there is nothing to check the flow of this energy to the end of the nerves, which, for example, again let us say, is the stomach and bowels, as in cerebro-spinal meningitis or cholera infantum.  The nerves are running away.  They are wild and over-excited.  Here the Osteopath shines by making mechanical pressure or inhibition over the sympathetic nerve centers for the stomach and bowels.  He checks this flow of nervous energy, gives the end nerves a chance to settle down and become sedative, and the demonstration, i. e., vomiting and diarrhoea, ceases.  In this case you are apt to have a too relaxed muscular and tendinous system and your patient needs a course of general treatments, with cautious and proper diet to tone up these flabby tissues and make them hold the structures, to which they are attached and with which they are surrounded, in their proper places, to give normal strength and tone to the blood vessels and to treat the irritable nerves in a pacific or sedative manner. All this after the acute symptoms have abated.  Hazzard gives the following points from Quain, and other authorities.  I venture to quote them here because what he says in regard to the phrenic nerve is true of much of the nervous system and is an example of the theory upon which the Osteopath works:

    He says the phrenic nerve arises from the third, fourth and fifth cervical nerves, especially the fourth, having branches from the third and a recurrent branch from the fifth.  It is reached in different ways, being impinged against the transverse processes of the vertebrae, or being reached at the fonticulus gutteris, or behind the first rib and the clavicle.  It is important to us mainly as a means of stopping hiccoughs.

    Gray says that the phrenic supplies the pericardium and the pleura by filaments; that in the thoracic cavity a filament is sent from the sympathetic to join the phrenic nerve, and that there are also branches to the peritoneum.

    From the right nerve there are branches to the phrenic ganglion, which is situated just below the diaphragm, the terminals perforating the diaphragm to reach the phrenic or diaphragmatic ganglion of the sympathic.  This ganglion of the sympathic is connected with the solar plexus.  This ganglion sends branches to the hepatic plexus and also some filaments to the inferior vena cava.  Its function as a spinal nerve is to supply the muscle of the diaphragm.

    From the left nerve branches go to join the solar plexus, but there is no ganglion formed.  Quaine, as quoted by Hazzard, substantiated these points and says further that branches reach the phrenic in the neck, going to the pericardium, and that from the right nerve are branches going to the inferior vena cava both above and below the diaphragm, and that branches also go to the right auricle of the heart.  Pausini, according to Quain, has found in animals that the phrenic plexus of the diaphragm is participated in by the lower three intercostal nerves.  You will see that the purpose is to associate the muscles of respiration, the abdominals, intercostals and the diaphragm itself.  Quain states further that the phrenic may have a branch from the hypoglossal nerve and from the fifth cervical nerve.  Such are the facts in relation to the phrenic and its distributions.  Hazzard says when we examine those facts in the light of Osteopathy it seems certain that we find the phrenic significant to us in more ways than one, you see that the phrenic is connected with the sympathetics: first with the middle or lower sympathetics in the neck; next that it receives a filament from the sympathetic in the chest; next that it perforates the diaphragm to join the nerves of visceral life, those on the right running from the diaphragmatic ganglion, those on the left joining without the intervention of a ganglion.  You notice further that it has a connection with a cranial nerve -- the hypoglossal; that it has branches connected with the brachial plexus, that is, from the fifth cervical; and that it may perhaps join with the lower three intercostals, but I do not know that -- that has never been shown to be true in man.  The conclusion is obvious from what we know of the connection of nerves in different parts of the body, both sympathetic and otherwise, that if any of these sympathetic spinal or cerebral nerves were diseased the disease might conceivably be extended to the phrenic and affect it, and that we might have phrenic symptoms arising from these other troubles.  The reverse, of course, is true and that any of these structures which are supplied by the sympathies or these other nerves may reflexly be affected by the phrenic nerve when diseased.  You have seen that it supplies the pericardium, pleura and peritoneum, and it supplies one of the great blood vessels, the inferior vena cava, and sends branches to the right auricle of the heart, and there is no reason, according to our theory, why disease in any of these situations might not affect the phrenic nerve, and you might have symptoms of disease in the phrenic nerve.  So that our theoretical rule is certainly a good one, for it works both ways, either in affecting the phrenic nerve or the other structures, as the case may be.  The importance of this to us lies in the fact that it would be an adjuvant in the treatment already used.  It is one more path by which we can influence nerve force.  We have certain ways of reaching the abdominal viscera through the splanchnics in the back.  We might have a case that we could not affect in that region, but if we could reach the trouble through the phrenic we could accomplish the desired result.

    So in our work upon abdominal viscera may we avail ourselves of the advantage of work in the neck on the phrenic.

    Hazzard quotes Dana as saying there is a motor area in the neck which is readily affected by the electric current and he treats here for diaphragmatic palsy.  Hazzard thinks this corresponds to the work done by the Osteopath when he makes pressure directly on the phrenic nerve.

    Hazzard quotes from Dr. Jacobson along this line as follows: "Another reason for the phrenic nerves traversing the diaphragm and breaking up into branches on its under surface may be to enable them to come into communication with the sympathic or visceral nerves of the abdomen.  From this communication branches are given to the hepatic and solar plexuses, and the inferior vena cava.  Every one knows the value of active exercise when certain abdominal viscera are torpid in the performance of their functions, e. g., in constipation, biliousness, etc.  Hence we see that we can go farther and say that since the brain and cord are thus brought into connection through the phrenic with the sympathetics and with abdominal sympathetic life, and since the brain must send certain impulses along those nerves and thus affect the abdominal sympathetic nerve life, there is no reason why the reverse may not be true.  Why may we not affect the brain and cord by working back from the sympathetics and more particularly when there is a lesion, because manipulation must tend toward the normal?  You would manipulate the phrenics, the abnormalities would be affected, you would affect the phrenic, and thus be more likely to affect other nerves which have under control that which has become abnormal.  There is no reason., according to our theory, why we would not tone up the whole mechanism of respiration, especially the muscular respiration, since it is in connection with the phrenic nerve and with the abdominal sympathic."