As Published in the Journal Today’s Chiropractic; Vol 28, No 2: 30-45

Does The Subluxation Exist In Clinical Practice?

     Does this question seem absurd to you? Over 100 years of clinical experience tells us that when an adjustment is rendered properly something positive occurs to the patient. However, how much of a positive effect, and on what type of conditions, is another matter. If the subluxation does exist, and its effects are as detrimental as we claim, then our care should be effective and reproducible on a myriad of conditions. Unfortunately, this is not the case in many practices. The problem lies in objectifying the existence of the subluxation, and more importantly proving that the adjustment has corrected it. Without this knowledge, how can we properly dictate where and how an adjustment is rendered? Perhaps this is why our profession is slowly being displaced into the realm of musculoskeletal treatment and eroded as a distinct and separate form of health care.

     What methods are in use today that can objectively assess the existence and correction of subluxations? It seems that our profession is readily able to affirm that the subluxation is what we rectify, but leaves us without methods of objective analysis. This has caused a grave lack of reproducible results on serious health conditions within many practices. Consequently, the question of the existence of subluxation is very real to you whether you like it or not.

The Vertebral Subluxation Complex 

     If we are to claim that subluxations do exist, we must first be able to define what they are. The first complete definition of a subluxation was postulated in 1906 by Dr. Palmer, "A subluxation is a partial dislocation, slightly separated from its articulating surfaces. The subluxation partially occludes the intervertebral foramen, producing pressure upon nerves as they emanate from this opening, hence impulses are hindered" (1). From this first definition the subluxation has developed into a description as a complex of events; and as such, renamed the vertebral subluxation complex (VSC). With time the VSC has evolved into three models:

5 Component VSC Model (2) -

9 Component VSC Model (3) -

3 Component VSC Model (4) -

     Regardless of the elegance of these theoretical models, we seem no closer to a truly operational definition of the subluxation. Operational to the extent that the definition of the subluxation can be used on a daily basis in patient care. What the field practitioner needs is a model that can be supported by objective evidence and implemented in a clinical setting. Under the current models, must all of the components of the VSC be present for the subluxation to exist? If a patient presents with one component missing are they without subluxation? If we hold ourselves to this level of scrutiny, how could we possibly measure all of these components on a daily basis both pre and post-adjustment? What then, must be present for a subluxation to exist?

     The problem lies in the essence of the subluxation. It has been postulated that, "Common to all concepts of subluxation are some form of kinesiologic dysfunction and some form of neurologic involvement" (5). This statement couldn’t be more true. You will notice that in all the above VSC models some form of kinesiologic and neurologic dysfunction is present. We believe that the operational definition of the subluxation is far less complex than currently theorized.

     In a landmark decision, the Association of Chiropractic Colleges established a position paper in July of 1996 defining the practice of chiropractic: "The practice of chiropractic focuses on the relationship between structure (primarily the spine) and function (as coordinated by the nervous system) and how that relationship affects the preservation and restoration of health" (6). Soon after, the Congress of Chiropractic State Associations endorsed and adopted this same position (7). In order to fully appreciate the magnitude of this historical document, we must understand that every chiropractic college president agreed to and signed this paper with all the state associations accepting and adopting this same position. It seems that a consensus over two entities has taken place over what we do as chiropractors.

     From a synthesis of this information, it appears that there may be a more simple and cohesive operational definition of the subluxation. If we examine what is occurring physiologically, we can see exactly what the subluxation is and what its effects are (Fig. 1). The subluxation begins with some form of insult to the articular structures of the spine. This insult may be in the form of sports injuries, falls, motor vehicle accidents, prolonged exposure to incorrect occupational postures, birth trauma, or other entities. This initiates aberrant segmental arthrokinematics through intra-articular fixation (8-11). From this comes the genesis of neuropathophysiology via dysafferency or compensatory hyperafferent bombardment of the central nervous system (12-17). Finally, this results in a cascade of events that are the component effects of the subluxation.

     To clarify this, aberrant arthrokinematics refers to specific segmental biomechanical articular dysfunctions of the spine and not global altered ranges of motion as the VSC components of dyskinesia or kinesiopathology describe. These again, are effects of the subluxation and not the cause. Along this same vein are the static model concepts of spinal architecture. The various models of "normal" vs. "abnormal" spinal curvatures make interesting assumptions concerning subluxation. Do altered spinal curvatures effect neurophysiology? If they do, what magnitude of aberration is necessary to cause neuropathophysiology? Or, are the alterations of these spinal curvatures the effects of the subluxation’s neuropathophysiology?

     Dysponesis, myopathology, and myology, as noted in the above models, are also considered effects. Most importantly, all of these component effects may or may not be present with a subluxation. This point cannot be stressed more fervently. Other than specific segmental aberrant spinal arthrokinematics and neuropathophysiology, nothing else has to be present for a subluxation to exist. Neuropathophysiology is the heart of the subluxation from which all other dysfunction follows.

     Consequently, the VSC as we know it is truly based upon two events with a cascade of effects (Fig. 1). Since the nervous system controls and coordinates every function in the body, a position even our colleges and state associations can agree on, all the other components are merely effects of the subluxation. From this we hypothesize that the best operational definition of the subluxation would be as follows:

2 Component Model of the Vertebral Subluxation –

     The "complex" portion of the vertebral subluxation is not discarded, but put in its rightful place as the cascade of effects resulting from the two component genesis. This leaves us in clinical practice with a truly operational definition of the subluxation. A definition which can be put into direct use on a pre and post adjustment basis in daily patient care. Since the other entities are effects, their measurement can yield misleading information as to the presence of the subluxation. Therefore, daily analytical methods must focus on the aspect of the subluxation that causes these effects: neuropathophysiology.

Objectifying the Presence of the Subluxation 

     What, then, are we doing to objectify the existence of the subluxation in our patients? What are we doing to measure what science has determined to be the most detrimental of all system malfunctions? If we are to claim that subluxations do exist, there must be a way to identify their presence before care is rendered and their eradication after an adjustment is given. Many different types of subluxation analyses are used in our profession such as static and motion radiography, leg length, cervical challenge, motion and static palpation, and others. However, these procedures have no literature confirmation of their ability to monitor neurophysiology and most possess inherent errors along with a lack of objectivity (18-21). Since neuropathophysiology must be present at all times for a subluxation to exist, this presents us with a singular distinctive component that may be used to detect this seemingly elusive entity.

     What is needed is an objective method of analysis that only an instrument can provide; an analysis which detects the subluxation via measurement of autonomic neurophysiology. Evaluating autonomic neurophysiology allows us to remove the examination subjectivity of patient compliance while fulfilling our need for neurophysiological responses on visceral function. The device must also be sensitive enough to detect the first signs of neuropathophysiology; a minimum requirement for preventive care. It must be easy to use, fast enough to perform daily pre and post adjustment tests, and devoid of the subjectivity of patient compliance (tests that need the patient to cooperate: motionless posture, motion, verbal responses, etc.). And finally, the device must have ample research behind it to support its accuracy, repeatability, stability, sensitivity, specificity, and validity in the area of neuropathophysiological analysis. Research which has also determined a standard for normal neurological function, thus providing a normative database to which the patient can be compared.

     The only instrument available at this time, which meets every one of these criteria, is paraspinal digital infrared imaging (a.k.a. thermography). Paraspinal infrared imaging fulfills this need by objectively measuring the autonomic changes of all 32 spinal nerves as they exit to effect deep visceral function. Since testing does not involve patient compliance, computerized paraspinal thermal imaging becomes as objective a test of neurophysiology as we can get. With the event of this technology, the field doctor now has the means of monitoring nervous system function on a pre and post adjustment basis; thus fulfilling the needs of modern outcome based care. For the first time, the patient and the doctor are both able to determine objectively how much neurophysiological improvement has been made and when more care is indicated.

     However, paraspinal thermal imaging is only as effective as the design of the instrument used. If the device cannot trace exactly over the path of a previous scan, collect enough thermal readings along the spine (thermal resolution), and/or the sensors are unstable, factual data will not be gathered. These are just a fraction of the problems that may be encountered with currently available devices. The thermal data must also be processed correctly and displayed in a format that is acceptable for proper clinical analysis. Consequently, our association (the International Upper Cervical Chiropractic association) conducted considerable clinical and laboratory research into many of the current and past devices used in paraspinal thermal analysis.

     The depth of this article does not permit a full explanation of every detail and research parameter undertaken in testing these devices. Suffice it to say that each instrument was either "out-of-the-box" new, or as close to this as possible, and subjected to bench standard and human analysis under laboratory conditions by experts in the fields of engineering, physics, and clinical thermography. A simple summary is in order for a more complete understanding of the importance of some of the factors tested.

     To begin with, all contact instruments (thermocouple) are not currently suitable for proper neurophysiological analysis. Due to their inability to escape from the laws of thermodynamics, they simply alter factual gathering of true surface temperatures by mere contact with the skin. This is but one of the many problems encountered with these older instruments (22). However, these devices served our profession well at a time when there were no other technological choices and human thermal analysis was not fully understood. Nonetheless, extensive continued research in this field dictated certain technological advances in order to provide accurate assessments of human neurophysiology.

     It is essential that a paraspinal instrument be designed with a fixed probe width and adequate thermal shielding for sensor stability. If the probes, and thus the sensors, are allowed to move the temperature reference mass will be insufficient to stabilize the sensors. This, along with the type and quality of the sensor itself, allows for the accurate temperature readings necessary for interpretation of autonomic neurophysiology. Computerized (a.k.a. digital) scan analysis is currently assumed in this day and age where precision accuracy is involved with data acquisition and clinical interpretation. The use of the computer has allowed for precise on-screen analysis of every data point, graph-fit pattern analysis, and an increase in thermal resolution (the ability to gather enough infrared samples for proper clinical interpretation). Some instruments are of such low thermal resolution that they are only capable of simple bar graph displays.

     Any device that only produces a delta-T, or differential line graph, is grossly incomplete in displaying the patient’s presenting neurophysiology. The DTs, or direct temperatures over each side of the spine, must also be displayed as high-resolution line graphs in order to insure proper pattern analysis. The design of past instruments left the doctor blind in this respect. With the inclusion of the DTs, we now know that it is possible to have a particular scan’s delta-T match the patient’s original presenting scan (their pattern) with the patient not in pattern. High-resolution graphics are also the norm in today’s clinical environment. Patients do not always understand line graph displays. A high-resolution anatomical image gives the patient the information in a format that they can understand (Fig. 6) while maintaining the line graphs for the clinician’s needs. Along with this is the ability of the computer software to produce clear, concise, and fully referenced narrative reports. The ability to convey information that the patient can take home and study, or an insurance company can examine, is essential in this information age.

     The method that the instrument uses to repeat a given scan on a patient is extremely critical for accuracy, reliability, and repeatability. Many devices use the manual method that depends totally upon the doctor for anatomical placement and/or scanning cadence. It can take up to a year of daily clinical use to obtain the skills necessary to produce even fair scan repeatability. Some devices have attempted to improve upon this by using audible tones to aid in timing a scan. Again, this takes a great deal of training and time to learn to produce only a fair amount of repeatability. Modern fiber-optic distance encoders have completely replaced these older methods and insure precision repeatable length scans. This ability is also directly linked to anatomical location. If the instrument can accurately measure, and thus repeat a scan, mathematical extrapolations can be made with a resulting display of high anatomical location accuracy.

     In order to meet critical thermographic industry standards, an instrument must also be manufactured and calibrated to meet certain criteria (23-24). If this minimum standard is not met, the instrument is not acceptable for clinical use. With this in mind, FDA registration and compliance with their biocompatability standards is another important feature in any modern clinical examination instrument. Meeting these requirements insures a level of quality in both the manufacturing and abilities of the instrument in question.

     From our research we found only one instrument that meets the proper criteria for accurate and reliable paraspinal thermal imaging, the TyTron C-3000. Our association has chosen this instrument as the primary tool for use in the detection of the subluxation. This device exceeds stringent thermographic equipment manufacturing guidelines and is FDA registered as a neurophysiological diagnostic device. It incorporates extremely sensitive (up to 1/100th of a degree C) and stable infrared sensors, high resolution thermal data collection (up to 600 IR samples for a full spine scan), fiber optic communication, beam collimating lenses, distance encoders, and extensive computerized scan analysis. Consequently, this cutting-edge technology insures that the practicing field doctor can produce accurate, repeatable, and valid paraspinal infrared scans.

     With the use of this modern instrument, pre and post adjustment scans dramatically demonstrate to the patient their nervous system's improvement with care. (Fig. 2 & 3)

Fig. 2

Fig. 3

     The scans may also be displayed for your patients as high-resolution full color spinal images with bar graphs representing 1-3 standard deviations from the norm (25-27). (Figs. 4 & 5)

Fig. 4

Fig. 5

     Past office visit scans may also be viewed as a multiple comparison image for tracking patient improvement and the need for future care.

Fig. 6

     (Note: Notice the repeatability of the full spine scans performed on this patient. This example was taken from an inter/intra-examiner reliability study of 60 patients and consists of blinded scans performed by three doctors of varying experience (28)).

     Moreover, this system has the ability to display pre and post adjustment scans as an overlay graph or side-by-side spinal images. (Fig. 7). The design of this system also allows for accurate readings into the hairline and up to the occiput without thermal distortion. For doctors who may be taking mostly cervical scans, C-spine scans alone can be displayed as an option in either line graph or spinal image formats (Fig. 8).

Fig. 7

Fig. 8

Research and Paraspinal Digital Infrared Imaging 

     There is no longer any doubt in the health sciences about the importance of the nervous system. Cutting edge research into the exact level of control the nervous system exerts has uncovered processes that stagger the imagination. The discovery of brain cell hibernation stunned the research community with the knowledge that neurons could actually remain dormant for decades awaiting awakening by a slight increase in blood supply (29-35). Studies have also found a direct two-way communication system between the brain and every cell in the body (36-40). The amount of research supporting chiropractic's core principle is enormous. These combined technological advances in neurobiochemical and neurophysiological research have established with certainty the nervous system's dominance in controlling and coordinating all bodily functions. It seems that science has finally caught up with our 100 years of clinical observations.

     We as a profession have a responsibility to both the patient and ourselves to monitor the subluxation through the nervous system due to its unique role in the maintenance of global bodily function. Over 30 years of research, almost 9,000 peer reviewed and indexed studies, and a high degree of sensitivity (99.2%) and specificity (98%) have confirmed infrared imaging as a valid analysis of neurophysiology (41-47). Both the chiropractic and medical professions have issued policy statements confirming infrared imaging’s validity as a neurodiagnostic tool (48-51). The medico-legal system has allowed thermal imaging to be introduced as court evidence for over two decades (52-53). Federal agencies and departments have also issued position papers on its usefulness and efficacy. The weight of the evidence lends overwhelming support to thermal imaging as a valid procedure for the analysis of neuropathophysiology.

A Challenge 

     Does the subluxation exist in clinical practice? Do we know for a fact that we correct them? Are we absolutely sure our patients are not made worse with our care? How do we know which adjustment is most efficacious? We as a profession stand on the principles of the vertebral subluxation, yet examine our patients with subjective measures. Can we as field practitioners truly answer these questions without objective instrumentation?

     As part of their previously mentioned landmark position paper (6), the Association of Chiropractic Colleges also expressed that, "The ACC advocates a profession that generates, develops, and utilizes the highest level of evidence possible in the provision of effective, prudent, and cost-conscious patient evaluation and care". We have the ability at this time to provide what this position paper advocates. The highest level of evidence possible for the existence of the subluxation lies in the realm of paraspinal infrared imaging. Objective detection of the subluxation before adjusting, and proof of its eradication afterwards, provides for the finest in cost-conscious patient evaluation and care. The position of the ACC fits with what we think is the truly operational definition of the subluxation: specific segmental aberrant spinal arthrokinematics with resulting neuropathophysiology. With this model, and current paraspinal infrared imaging technology, field practitioners have the ability to provide care from the heart of the subluxation.

     If the chiropractic profession is going to continue to stand on its core principle that the subluxation, and its adjustment, affects the neurophysiology of the body, then we must directly and objectively monitor this system as an outcome measure to our care. Regardless as to whether or not you "believe" in any particular technique, we as profession must insist on the highest standards possible in the detection and correction of the subluxation. Only then will we truly discover what works and what doesn't. Does the subluxation exist in clinical practice? This is the question you must answer.

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