A lot of research has been undertaken in the osteopathic field. Some relates to the way the musculo-skeletal system influences general body health and function; that is the actual changes that occur—especially in the spinal region—and the consequences of these changes. This area of research has produced great insight into the physiology and pathology of the body, whilst other research has been concerned with attempts to validate osteopathic diagnostic and therapeutic measures. This has helped to establish more clearly what is, and what is not, valid in these fields but, as with so much of research, more questions are raised as others are answered.
A major area of research was identified in the late 1930’s by Dr J. Denslow, who began testing spinal dysfunction by means of pressure meters and electro-myographs (recorders of muscular contraction and relaxation). He was able to show that the areas of dysfunction required a smaller stimulus to produce muscular changes than in normal areas of the spine. In this way he demonstrated for the first time the accuracy of what had previously been the osteopath’s subjective assessment through palpation that something was wrong in a particular area.
Having established that thresholds were low in areas of dysfunction, further research was needed to work out why this was so and to analyse the implications. Fortunately for osteopathy this task was undertaken by Professor Irvin M. Korr Ph.D., a biochemist and leading researcher into osteopathy, who showed that when a spinal segment was in this state of over-excitability it could be stimulated, or activated, by pressure or irritation from other apparently normal segments, even some distance above or below it. When the area of dysfunction was anaesthetized it could no longer be made to respond by local pressure, but would still respond to normal segments, above or below it, being pressed. At the time such troubled segments were termed ‘facilitated segments’.
Professor Korr realized that pressure was, in general terms, an unnatural test of body response, and he therefore introduced other stimuli to the subject being tested, such as sudden loud noise, painful stimuli, or verbal stimuli (embarrassing questions or faked bad news). In all cases the ‘facilitated segments’ (the areas of lowered threshold) were the first to show a reaction, and the muscular overactivity in such regions was the last to cease when the subject relaxed. This work was reported by Korr and his associates in 1947, and he described the process as being ‘like a neurological lens which focused irritation upon the lesioned segment and magnified its responses.’ 
Investigations were then made into what was happening in such segments to the sympathetic nervous system, and the possible ramifications in the body as a whole. This involved mapping the patient’s skin surface for variations in electrical resistance and temperature. This produced a visual record of the sympathetic nervous system behaviour, as reflected by sweat gland activity and blood flow, under the skin, of any given area at a particular moment in time.
This system has been superceded by infra-red photography as well as by the use of sophisticated electronic apparatus which simultaneously measures eight different spinal segments. All this has proved that there exists a correlation between the lesioned segment (area of somatic dysfunction) and the abnormal behaviour of motor and sympathetic nerves that are segmentally related to the lesioned area.
Patterns of Dysfunction
Over the years Korr began to establish consistent patterns of sympathetic nerve function disturbances and specific organ diseases, especially where pain was a major factor, such as pancreatitis, peptic ulcer, gall bladder disease, menstrual pain, colic, kidney stones etc. Often students who had volunteered for assessment were noted as having patterns of dysfunction which later would show up as a specific disease pattern.
Professor Korr admits that much work in this field remains to be done, but he states that when a condition of chronic facilitation exists in a spinal segment, ‘We cannot say that this 24-hours-a-day state of alarm results in illness on a definite one-to-one basis. We can only say that these disturbed segments are relatively vulnerable, that the probability is higher. Whether or not it becomes clinically significant depends upon the person we are dealing with and all the circumstances of his life, past, present and future. Here is where other unfavourable circumstances in the patient’s daily life may tip the balance; here is where an abnormal stress response will tend to find the earliest and most severe expression.’ 
In addition to this line of research Professor Korr has done much work on the trophic function of nerves (concerning the nutrition of the tissues). Nerves not only conduct impulses but supply proteins and other substances to the tissues and organs with which they connect. These substances are essential for the maintenance and self-repair of the tissues, and they influence their total function. In considering the implications of this, Korr states that any factors that interfere with this aspect of nerve function may contribute towards disease. He says:
Such factors could include disturbances (e.g. emotional stress) in descending impulse traffic from higher centers, impulse traffic in sensory pathways from various parts of the body, nutritional factors, drugs, toxicological agents, viral insults, changes in the chemical environment of the neurons and their axons (nerve cells) and, of course, the mechanical stresses and large forces exerted on and generated by the myofascio-skeletal tissues through which the nerves pass, and the accompanying chemical changes in these tissues. It seems likely that the efficacy of manipulative therapy may occur in part through alleviation of some of these detrimental factors.
More recently it has been shown that the flow of material along nerves is a two-way traffic. The retrograde transport is seen as a means of communication, or feedback (literally) between the nerve cells and the cells they supply. Korr states:
Any factor that causes derangement of transport mechanisms in the axon or that chronically alters the quality or quantity of the axonally transported substances, could cause the trophic influence to become detrimental. This alteration in turn would produce aberrations of structure, function and metabolism, thereby contributing to dysfunction and disease.
Almost certainly to be included among these harmful factors is the deformation of nerves and roots, such as compression, stretching, angulation and torsion, that are known to occur all too commonly in the human being, and that are likely to disturb the
intra-axonal [nerve cell process] transport mechanisms, intraneural [nerve cell] micro-circulation [circulation in the smallest blood vessels] and the blood-nerve barrier. Neural structures are especially vulnerable in their passage over highly mobile joints, through bony canals, intervertebral foramina [apertures], fascial layers [fibrous tissue beneath the skin] and tonically contracted muscles (for example, posterior rami [branches] of spinal nerves and spinal extensor [stretching] muscles.) Many of these biochemically induced deformations are, of course, subject to manipulative amelioration and correction. 
As Paul Thomas D.O. states:
This appears to be a part of the long sought answer to the question of exactly how the nerves influence the structures innervated, with respect to metabolism, development, differentiation, regeneration, and trophicity in general. The treatment of an organ through its innervation is an element in present manipulative therapy. The new information regarding neural function may lead to specific improvements in technique. 
This knowledge, plus the segmental facilitation research of Korr and his associates, gives a scientific basis for the claims of osteopathic medicine; i.e. that dysfunction of the musculo-skeletal framework of the body can have profound effects on the health of the individual.
Research Into Diagnostic Methods
Research into the ability of osteopathic diagnostic methods to elicit accurately such dysfunction has also been carried out and evaluated. Between 1969 and 1972 over 6,000 patients admitted to Chicago Osteopathic Hospital were part of just such a clinical investigation. Visual and palpatory observations made by attending osteopathic physicians were recorded and analysed in relation to the health problems of the patients. The findings showed a clear link between the spinal area, diagnosed by the examining practitioner as being involved, and the corresponding diseased organs of the patient. The conclusion was: ‘The somatic findings in over 6,000 cases of hospital patients support the osteopathic theory of viscero-somatic (internal organs and the body) relationships.’ 
In clinical situations a variety of findings over the years have tended to validate the osteopathic concept. One such investigation related to the study of the relationship between disorders of the pelvic and thoracic organs, and spinal findings. It was ascertained that the following three palpable findings occurred in statistically significant numbers of tests:
Restricted intervertebral motion occurring alone.
Restricted intervertebral motion occurring in combination with abnormal vertebral position.
Restricted intervertebral motion occurring in combination with abnormal paravertebral musculature.
The cases assessed were of uncomplicated disorders of the heart, aorta, bronchii and lungs (86 cases) and disorders of the female genitalia (101 cases).
Research was carried out in 1965 at Los Angeles County Osteopathic Hospital into the effects of osteopathic care of children with pneumonia.  Here 239 cases of various types of pneumonia in children over a three year period were analysed. The results showed that there was a favourable comparison with results of treatment in non-osteopathic institutions of a similar nature.
Around the same time research was also conducted into the possibility of a musculo-skeletal connection in cases of cardiac disorder, and the results yielded strong evidence of such a correlation.  Palpatory, and x-ray findings, as well as prior fluoroscopic and E. C. G. readings, showed that a majority of the 150 patients in the tests had associated asymmetrical spiral aberrations and corrective spinal treatment was consistently found to be followed by varying degrees of relief from cardiac symptoms. These changes were reflected in objective clinical and laboratory tests.
More recently, in 1981, doctors at Riverside Osteopathic Hospital in Trenton, Michigan, undertook an investigation to establish the existence of a viscero-somatic reflex that could be easily detectable and which would correlate with the presence of athero-sclerotic coronary artery disease. In all, 88 consecutive cases, each suggesting coronary disease, underwent cardiac catheterization, and within one week of this, each patient in turn was given standard osteopathic musculo-skeletal evaluation (pain, range of movement, soft tissue texture etc.) by an examiner unaware of the results of the cardiac catheter probe. The results showed a correlation between coronary atherosclerosis and abnormalities of range of motion and soft tissue texture in the fourth and fifth thoracic and the third cervical intervertebral segments. 
At the same time research at the Philadelphia College of Osteopathic Medicine demonstrated that there occurs a definite, measurable and significant drop in the intraocular pressure following osteopathic manipulative therapy.  This is of great significance to patients with chronic open angle glaucoma.
Such research efforts are constantly being undertaken to establish the value of osteopathic treatment, and the fundamental and far-reaching results obtained by Professor Korr and others, as well as the cumulative evidence of many groups and individuals in the clinical field, have gone a long way towards this end already.
1. “The Neural Basis of the Osteopathic Lesion’, The Journal of the American Osteopathic Association 47: 191-198 (1947).
2. ‘The Trophic Function of Nerves and Their Mechanisms’, The Journal of the American Osteopathic Association 72:163-171 (1972).
3. ‘The Spinal Cord as Organizer of Disease Processes’, The Journal of the American Osteopathic Association, Vol. 80, No. 7, page 458.
4. Osteopathic Medicine, Hoag, Cole and Bradford (McGraw Hill 1969).
5. ‘A Clinical Investigation of the Osteopathic Examination’, Kelso, Larson and Kappler, The Journal of the American Osteopathic Association, Vol. 79, No. 7, page 460.
6. ‘Pneumonia Research in Children at L.A.C. Osteopathic Hospital’, Warson and Percival, Yearbook of the Academy of Applied Osteopathy, 1965, page 152.
7. ‘A Somatic Component in Heart Disease’, Richard Koch D.O., The Journal of the American Osteopathic Association, May 1961.
8. ‘Palpatory Musculo-skeletal Findings in Coronary Artery Disease: Results of a Double Blind Study’, Cox, Rogers, Gorbis, Dick and Rogers, The Journal of the American Osteopathic Association, July 1981.
9. ‘Evaluation of Intraocular Tension Following Osteopathic Manipulative Therapy’, Paul Misischia D.O., The Journal of the American Osteopathic Association, July 1981.