Chiropractic & Manual Therapies - Latest Comments

Rebuttal of this article

Bruce Walker — 2012-03-30T06:17:19Z

A rebuttal article to this paper has been published in this journal. see:
Haas M, Cooperstein R, Peterson D. Disentangling manual muscle testing and Applied Kinesiology: critique and reinterpretation of a literature review. Chiropr Osteopat. 2007 Aug 23;15:11.

Insufficient evidence was provided to support statements about subluxation

Michael Haneline — 2011-06-28T06:48:43Z

The authors state in their conclusion that ¿The concept of the subluxation in chiropractic is a controversial subject with a paucity of evidence.¿ but do not provide enough evidence to adequately support this statement in their paper. In fact, no definition of subluxation was given in the article and little was mentioned about what evidence exists for or against the use of the term subluxation. The purpose of this study was to determine the prevalence of the usage of subluxation in the North American English-language chiropractic college catalogs and academic bulletins. The authors should have adhered to their predetermined purpose and refrained from hyperbole about the subluxation.

The following sentence appears to make a key point in the paper, but it is grammatically incomplete and unclear. ¿The most frequently encountered unsubstantiated claim related to the putative clinical meaningfulness of subluxation.¿ Perhaps ¿is¿ should be inserted after ¿claim¿ in order to connect the first half of the sentence with the second half, or additional material should be added after ¿subluxation¿.

As far as the term ¿subluxation¿ is concerned, it has been defined in multiple ways; some of which are sensible, whereas others are absurd and unsubstantiated. The fact remains that chiropractors and many manual therapists manipulate/adjust the spine to correct spinal dysfunctions comprising abnormalities such as restricted motion segments, muscle tension and pain. Would it not be reasonable to label this type of dysfunction ¿subluxation¿?

Michael T. Haneline, DC, MPH - Head of Chiropractic
International Medical University
Kuala Lumpur, Malaysia

Commentary on `Routine versus needs-based MRI in patients with prolonged low back pain: a comparison of duration of treatment, number of clinical contacts and referrals to surgery¿

Brian Clark — 2011-05-31T10:28:48Z

Commentary on `Routine versus needs-based MRI in patients with prolonged low back pain: a comparison of duration of treatment, number of clinical contacts and referrals to surgery¿

Brian C. Clark,1,2 Stevan Walkowski,1,3 David C. Eland1,3 and John N. Howell1,2

1Ohio Musculoskeletal and Neurological Institute (OMNI), 2Department of Biomedical Sciences, and 3Department of Family Medicine

Jensen et al., in a paper entitled `Routine versus needs-based MRI in patients with prolonged low back pain: a comparison of duration of treatment, number of clinical contacts and referrals to surgery,¿ investigated whether two magnetic resonance imaging (MRI) approaches resulted in differences in: 1) duration of treatment, 2) number of contacts with clinicians, and 3) referral for surgery. Specifically, the authors performed a retrospective analysis by taking advantage of recent policy changes in Denmark¿s health care system whereby many patients now receive an up-front routine MRI examination during their first clinic visit. The authors found that routinely performing an up-front MRI reduced the duration of treatment and the number of contacts with clinicians, and did not increase the rate of referral for back surgery or the direct financial costs.

Our particular interest in this article relates to the details of the MRI techniques utilized to examine pathology and abnormalities of low back pain. While the specific details of the MRI protocols employed in the work by Jensen and colleagues are not detailed, one must presume that these were standard musculoskeletal imaging protocols designed primarily to examine anatomical structures. In this commentary, we seek to highlight innovative advances in MRI that permit quantitative information to be derived. In particular, we discuss the potential utility of muscle functional MRI (mfMRI) in understanding the pathology of low back pain, which may help define optimal treatment strategies.

mfMRI allows non-invasive measurement of the metabolic and hemodynamic responses of skeletal muscle by observing changes in the contrast properties of certain magnetic resonance images that occur in skeletal muscle with activity [2-4]. In brief, muscle activity causes an increase in skeletal muscle proton transverse relaxation times (increased T2), with T2 changes within a muscle being sensitive to as few as two repetitions of resistance exercise [5]. While the physiological underpinnings of these changes are complex, they primarily result from increased rates of cellular energy metabolism, which alter the image contrast properties by increasing the water content and by decreasing the intracellular pH [2]. Fleckenstein and colleagues first reported in vivo imaging of muscle activation in 1988 when they demonstrated that active and inactive muscles could be clearly distinguished following exercise and that the activity-induced increase in signal intensity correlated with exertion [6]. However, more than two decades later, the clinical utility of mfMRI has only recently begun to be explored. For example, we have previously utilized mfMRI to study the spatial pattern of muscle activation in stroke patients with spasticity [7], and others have investigated the potential use of mfMRI in assessing cervical flexor activity in whiplash-associated disorders [8], as well as to identify damaged muscles from which enzymes are being released [9].

Perhaps most pertinent to chiropractors and osteopathic physicians is our most recent work using mfMRI to quantify and localize muscle activation abnormalities in patients with sub-acute low back pain, and to use mfMRI to assess the physiologic effects of manual therapies in treating low back pain [10]. In this study we observed muscle activity asymmetries (side-to-side T2 differences) in the lumbar extensor muscles (e.g., quadratus lumborum) in patients with low back pain in comparison to asymptomatic, healthy control subjects. Furthermore, we observed that a combination of osteopathic manipulative treatments functioned to reduce these muscle activation asymmetries. This work demonstrates the feasibility of mfMRI for quantification and localization of muscle abnormalities in patients with low back pain, specifically patients with sub-acute pain. These findings, and the potential use of mfMRI in the study of acute/sub-acute/chronic back pain, are particularly intriguing when considered in the context of one commonly touted model of the low back pain that involves muscle hyperactivity: the pain-spasm-pain model [11].

In summary, innovative advances in MRI, particularly mfMRI, over the past several decades now permit more sophisticated and quantitative information to be derived from MRI images. This information may help define optimal treatment strategies by providing information about underlying muscle pathology. The findings of Jensen et al. should be interpreted in light of the type of imaging performed in their retrospective study [1], and future work should explore the clinical utility of sophisticated imaging protocols such as muscle mfMRI.

REFERENCES

1. Jensen, RK, Claus M, and Leboeuf-Yde C. Routine versus needs-based MRI in patients with prolonged low back pain: a comparison of duration of treatment, number of clinical contacts and referrals to surgery. Chiropr Osteopat 2010, 18:19.
2. Damon, BM, Louie EA, and Sanchez OA. Physiological basis of muscle functional MRI. J Gravit Physiol 2007, 14(1): P85-8.
3. Meyer, RA and Prior BM. Functional magnetic resonance imaging of muscle. Exerc Sport Sci Rev 2000; 28(2): 89-92.
4. Patten, C, Meyer RA, and Fleckenstein JL. T2 mapping of muscle. Semin Musculoskelet Radiol 2003, 7(4): 297-305.
5. Yue, G, Alexander AL, Laidlaw DH, Gmitro AF, Unger EC, and Enoka RM. Sensitivity of muscle proton spin-spin relaxation time as an index of muscle activation. J Appl Physiol 1994, 77(1): 84-92.
6. Fleckenstein, JL, Canby RC, Parkey RW, and Peshock RM. Acute effects of exercise on MR imaging of skeletal muscle in normal volunteers. AJR Am J Roentgenol 1988, 151(2): 231-7.
7. Ploutz-Snyder, LL, Clark BC, Logan L, and Turk M. Evaluation of spastic muscle in stroke survivors using magnetic resonance imaging and resistance to passive motion. Arch Phys Med Rehabil 2006, 87(12): 1636-42.
8. Cagnie, B, Dolphens M, Peeters I, Achten E, Cambier D, and Danneels L. Use of muscle functional magnetic resonance imaging to compare cervical flexor activity between patients with whiplash-associated disorders and people who are healthy. Phys Ther 2010, 90(8): 1157-64.
9. Larsen, RG, Ringgaard S, and Overgaard K. Localization and quantification of muscle damage by magnetic resonance imaging following step exercise in young women. Scand J Med Sci Sports 2007, 17(1): 76-83.
10. Clark, BC, Walkowski S, Conatser RR, Eland DC, and Howell JN. Muscle functional magnetic resonance imaging and acute low back pain: a pilot study to characterize lumbar muscle activity asymmetries and examine the effects of osteopathic manipulative treatment. Osteopath Med Prim Care 2009, 3:7.
11. van Dieen, JH, Selen LP, and Cholewicki J. Trunk muscle activation in low-back pain patients, an analysis of the literature. J Electromyogr Kinesiol 2003, 13(4): 333-51.

Non-compliance-not just chiros AND Doppler to ease anxiety?

Michael John Haynes — 2010-12-07T21:28:43Z

Dear Editor,

Re; Langwworthy JM, Forrest L. Withdrawal rates as a consequence of disclosure of risk associated with manipulation of the cervical spine: a survey. Chiropractic and osteopathy 2010;18:27.

I congratulate the authors for their very important study[1] that was well designed, interpreted and written. I believe that there is no excuse for chiropractors failing to obtain informed consent from their patients regarding potential risks from cervical manipulation, and that this applies to all health care providers. While their findings suggest low levels of compliance (45% of respondents always complying) among UK chiropractors, they seem to be similar to compliance rates among Australian physiotherapists (37%)[2]. I have been unable to obtain figures for other health professional dealing with different therapies but I suspect, from my personal experience, that their compliance rates regarding informed consent are also low. The purpose of discussing this,is to provide some context to the problem that seems to be not confined to chiropractors. However, such discussion should not be viewed by chiropractors as an excuse to avoid their obligation.

I believe that the authors are correct when they explain that identifying patients at risk is inexact, and so informed consent needs to apply to all patients. They referred to evidence indicating that the pre-manipulative screening tests have little clinical usefulness, which applies to vertebrobasilar insufficiency provocation tests, which is reasonable. However, improvements in assessing vertebral artery patency for chiropractors using Doppler ultrasound velocimetry may assist in pre-manipulative screening [3]; an approach that is now taught to chiropractic students at the Institute of Franco-European Chiropractic.

There is mounting evidence that Doppler ultrasound is valid in detecting high grade stenosis of vertebral arteries due to various causes[4,5], such as vertebral artery dissection[6] and including cases that are neurologically silent[7].This is very important, as it may help screen for neurologically silent vertebral artery dissection[7],which is considered to be an absolute contraindication to cervical manipulation. It should also be noted that the animal model studies by Wynd et al[8] indicating tolerance of mechanically induced lesions of vertebral arteries to cervical manipulation, which Langworthy et al[1] mentioned, can not be extrapolated to humans, as acknowledged by Wynd et al[8].

While screening with Doppler ultrasound would not negate the need for informed consent, it could help ease anxiety of patients if they know that precautions are being taken that aim to reduce the risk of stroke following neck manipulation. Intelligent application of this technology should ensure that chiropractors are not lulled into a false sense of security, because no screening test is likely to be infallible.

References

1.Langwworthy JM, Forrest L. Withdrawal rates as a consequence of disclosure of risk associated with manipulation of the cervical spine: a survey. Chiropractic and osteopathy 2010;18:27.
2.Magarey ME, Rebbeck T, Coughlan B, Grimmer K, Rivett DA, Refshauge K. Pre-manipulative testing of the cervical spine review, revision and new clinical guidelines. Man Ther 2004; 9:95-108.
3.Haynes MJ. Vertebral arteries and cervical movement. Doppler ultrasound velocimetry for screening before manipulation.. J Manipulative PhysiolTher.2002;25:556-67.
4.Hennerici M, Aulich A, Sandman W, Freund H. Incidence of asymptomatic extracranial arterial disease. 1981 Stroke 12: 751-7.
5.Haynes MJ. Vertebral arteries and neck rotation: Doppler velocimeter and duplex results compared. Ultrasound Med Biol 2000; 26: 57-62.
6.Sturzenegger M, Mattle H, Rivoir A, Rihs F, Schmid C. Ultrasound findings in spontaneous extracranial vertebral artery dissections. Stroke. 1993:24:1919-21.
7.Krespi Y, Gurol ME, Coban O, Tuncay R, Bahar S. Vertebral artery dissection presenting with isolated neck pain. J Neuroimaging. 2002; 12: 179–82.
8.Wynd S, Anderson T, Kawchuk G. Effect of cervical spine manipulation on a pre-existing vascular lesion within the canine vertebral artery.
Cerebrovasc Dis 2008, 26(3):304-309.

Is ENAR really useful?

Leonardo Costa — 2010-11-05T05:58:09Z

I would like firstly to congratulate the authors for their trial. However it seems that neither the authors and the reviewers paid attention to a number limitations of the study that changes the conclusions of the study completely. In addition to the lack of intention to treat analysis and a loss of 20% of follow up (30/24) the biggest problem in this paper is that there is a clear imbalance of the baseline values from all outcomes observed (as can be easily seen in figures 2, 3, 4 and 5 and tables 4, 5 and 6), being the patients allocated to the ENAR intervention with higher levels of pain and disability. This issue could be explained due to the per protocol analysis, small sample size, randomization corruption or a combination of both. This imbalance is crucial to determine the between-group differences and therefore the effects observed by the authors cannot be attributed to the intervention. This is important for readers to know before they start applying this new intervention in their patients. I suggest to readers to be careful while interpreting this study and high quality RCTs are needed to test this new intervention.

Erratum to Leboeuf-Yde and Hestbæk's commentary: Chiropractic and children: Is more research enough?

Charlotte Leboeuf-Yde — 2010-07-02T10:06:29Z

The authors have found a typing error in the very last sentence under the subheading "Which diagnostic tests can we trust?". The faulty sentence is: "If the test is neither biologically implausible nor validated, it corresponds to a red light situation and should not be used."

However, this sentence should read:"If the test is neither biologically plausible nor validated, it corresponds to a red light situation and should not be used."

Our apologies to the readers!

Subluxation epidemiology: a response to Dr. Good

Timothy Mirtz — 2010-05-10T08:25:03Z

We wish to thank Dr. Good for his response to our recent work that was published in the December issue of Chiropractic & Osteopathy. In attempting to sift through the lengthy comment provided by Dr. Good we have chosen to only address the key points he makes.

We do not believe that the conclusion of the subluxation construct (SC) having “no valid clinical applicability” is flawed. Nor is it reckless and/or harmful. Simply put, if there is little or no data providing evidence of the SC combined with and the claim chiropractors make to treat this putative entity as a causal agent then its validity should be considered unproven. Until data comes forth that can adequately demonstrate the existence of the SC and provide the necessary data that demonstrates that it is a causative agent in disease or ill health then the SC should be regarded as having no such valid utility. One cannot say that some thing is causative for disease in the hope that someday science will somehow and some way catch up with it. We find this wholly unacceptable of any group of health practitioners to make such statements. It is not enough to accept the SC because a profession has historically “hitched its wagon” to a suspect entity.

Our intent, in writing the paper, was not in hope of unifying the profession or tearing it asunder. It was, however, an exercise in attempting to search the literature and apply the criteria of causation generally accepted by the epidemiological community. We are perplexed by Dr. Good’s assertion that our paper may have moved the profession further away from coming to a valid and respected unified position. In fact, the definition that we utilized was the ACC Paradigm which has been accepted by most, if not all, of the leading chiropractic organizations. It appears that the ACC Paradigm on subluxation is the unifying definition. For this reason we believe that using various definitions from various authors of chiropractic textbooks would have been problematic. It is worthy of note that none of the definitions in the works cited by Dr. Good provide any data that can attest to the SC being a causative agent in disease.

Dr. Good claims that the ACC Paradigm is outdated and ambiguous. We wholeheartedly agree with this assessment. We nonetheless disagree with the assessment that the ACC Paradigm is somehow “beautifully ambiguous.” We also suggest that the textbook authors various opinions on a SC definition are just as vague and ambiguous and lack the rigor of any substantive supportive scientific data.

It is not surprising to see Dr. Good (and possibly others) go directly to Sir Austin and examine his feelings on his very own work. It is true that Sir Austin did not intend for his criteria to be hard and fast rules. However, epidemiologists still refer to them and hold these criteria as foundational to the workings of epidemiology. In our work, we believed it was important to use his tenets to begin the investigation of the epidemiology of the SC. The use of the criteria provides a starting point for this investigation. In our investigation, we found no evidence to support the SC or an epidemiology for causation. Unless Dr. Good or any other person has solid evidence to support that the SC is causative we remain firm in our findings and our conclusions.

We do take issue with Dr. Good in his suggestion that we focused on a narrow element of the construct. As explained previously we utilized the ACC Paradigm which has been accepted by many leading organizations in the chiropractic profession. As well, Dr. Good alludes to the fact that there is a “joint subluxation/dysfunction syndrome.” This syndrome has never been documented to actually exist as a functional diagnosis nor does it have any evidence supporting it in relation to any known disease process. As per the consideration that the SC is somehow a “permutation” is nothing more than an attempt to offer some sort of validation to a construct that has not been scientifically validated. As well, the reference that 75% of chiropractors consider their clinical approach to be “subluxation-based” does not make the SC a reality or that there is sufficient research evidence suggestive that the SC is a causative agent. This is a common logical fallacy called the fallacy of consensus gentium (i.e. arguing that an idea is true on the basis that the majority of the people believe it.) Definitions that are commonly accepted for the subluxation have often been political in nature and cannot be used as testable models. Thus, a political definition such as put forward for the SC offers a difficult investigation using an epidemiological protocol.

Dr. Good noted our methodology. It is true that a systematic review would have included the number of “hits” in the search results and document inclusion and exclusion criteria. Nevertheless, using a very broad search strategy we were hard pressed to find any literature to support the SC that matched the definitions of the causation criteria. Furthermore, Dr. Good believes that other researchers are using terms such as “segmental dysfunction” and/or “spinal joint dysfunction” to describe the SC. To date, we are unaware of any serious research that describes “segmental dysfunction” and/or “spinal joint dysfunction” as causative of disease.

We take issue with Dr. Good when he stated that: “Ultimately the conclusion by Mirtz et al that the subluxation construct is in the realm of unsupported speculation cannot be made until it is supported by the findings of a comprehensive and properly performed systematic review and even then any conclusion would have to placed into context relative to the number of high quality studies that have actually been performed; without it their assertion is meaningless if not misleading.” We believe that the conclusion that the SC is in the realm of unsupported speculation due to the fact that there are no high quality studies that have validated the SC as causative. If Dr. Good has a number of high quality studies that leaves no doubt to the existence of the SC and these high quality studies scientifically verify that the SC is causative of disease then our opinion can be amended.

As stated previously, our intent, in writing the paper, was not in hope of unifying the profession or tearing it asunder. Nor was it intended to “bash” the profession or alienate or humiliate certain practitioners. Also, our intent in writing this paper was not to influence the general public or provide ammunition to chiropractic adversaries. We disagree vehemently with Dr. Good that researchers are somehow obligated to make sure that their research does not have political implications that could be construed as “costly.” We find the comments by Dr. Good in this regard to be very troubling.

In closing, we appreciate Dr. Good’s comments of our work. While there is little doubt that we are in disagreement with many of his responses, we suggest to Dr. Good that he provide the necessary data to support the existence of the SC that is testable, reproducible, and that there are screening measures that are valid to assess the SC. And when this is accomplished we suggest the next step would be to provide the necessary data, using the criteria of causation, in making the determination that this SC is a causative agent in disease. If this is achieved it falls to well supported chiropractic researchers to assess whether the act of spinal manipulation is a curative strategy. To date, none of these steps have been adequately fulfilled. This leaves us with no other conclusion than to suggest that the SC is a theoretical construct and at this time has only speculative clinical applicability.

Timothy A. Mirtz DC, PhD
Lon Morgan DC, DACBR
Lawrence Wyatt DC, DACBR
Leon Greene PhD

A Criticism of an Epidemiological Examination of the Subluxation Construct using Hill’s Criteria of Causation: Limitations, Suspect Conclusions and an Opportunity Missed

Christopher Good — 2010-05-06T02:38:58Z

As a chiropractic practitioner and educator over the past three decades I have been privileged to share the science, art and philosophy of the profession with thousands of patients, students and field doctors in both the United States and Europe. So it was with great interest that I read the work of Mirtz et al concerning the subluxation construct (SC) [1]. Indeed, their epidemiological examination of the SC utilizing Hill’s criteria was an opportunity to consider an important perspective regarding some of the evidence pertaining to it. It was also an opportunity to positively affect the evolution of the profession by buttressing the calls some academics have made to improve the SC, especially as it pertains to clinical practice [2,3]. Upon reflection however, it became apparent there were a number of critical shortcomings made by Mirtz and co-authors that rendered their final conclusions suspect, if not invalid. Specifically, the conclusions that the SC is “in the realm of unsupported speculation” and has “no valid clinical applicability” are not simply flawed, but in my view reckless and harmful. This may have moved the profession further away from coming to a valid, respected and unified position in regards to these matters; in essence a golden opportunity was missed. The purpose of this comment is to address the most important shortcomings of their article, identify information worthy of further consideration and make suggestions that would advance the understanding of the SC as reflected in contemporary chiropractic education and practice.

The first and most serious shortcoming involves a fundamental misuse of the work of Sir Austin Bradford Hill and the criteria he proposed to examine claims of causation between some agent or event and subsequent disease. Bradford Hill’s work has been chronicled by Yoshioka [4] and is illuminating to read. It begins in 1937 with a series of articles in The Lancet regarding the design of clinical trials (with a focus on randomization) and these eventually became the basis for his textbook on medical statistics. The story continues in the aftermath of WW II when tuberculosis was common and deadly and pharmacological interventions were being sought. The antibiotic streptomycin had recently been developed (1943) and because of its success in guinea pigs human trials followed. In 1946 a successful clinical study in England was performed using the new drug and this trial had the unique feature of including a randomly allocated control group as Bradford Hill had advocated. Over the next 20 years Sir Austin organized his thoughts regarding claims of causation primarily as they related to environmental exposures to toxins in the workplace. This culminated in his highly informative and entertaining address to the newly founded Section of Occupational Medicine of the Royal Society of Medicine [5] and gives a powerful depiction of the knowledge and attitudes of the man. His concern was focused on interpreting the observational evidence of the day, especially in the absence of more in-depth clinical research. But as important were the warnings he gave to those who would misuse his work, which is particularly relevant here:

"What I do not believe – and this has been suggested – is that we can usefully lay down some hard-and-fast rules of evidence that must be obeyed before we accept cause and effect. None of my nine viewpoints can bring indisputable evidence for or against the cause-and-effect hypothesis and none can be required as a sine qua non [5]."

It is clear from the preceding that Sir Austin did not believe that examination of any evidence by his criteria was the only means of determining the validity of claims of causation in a disease process. In fact that role is played by a well constructed randomized clinical trial (RCT) [6]. Currently it is suggested that Hill’s criteria are actually best utilized as an educated guess when observational studies or other data have been collected and are assessed. This is because Hill’s criteria have come under intense debate given the flaws inherent in their utilization, which begins with problems encountered in even defining the criteria themselves. For example, all of the criteria have been observed to be ambiguous, vague and/or have the potential to create any number of logical fallacies [7,8]. Instead, as Ward proposes, Hill’s criteria are best utilized as inferences of best explanation. Under this model the practitioner is warned of the flaws inherent in strictly applying Hill’s criteria and instead utilizes them as the basis for insight and further scientific investigation [6]. I would suggest that this is essentially where Mirtz and co-authors have gone astray. Their strict application of Hill’s criteria in regards to reviewing the literature is directly contrary to what Sir Austin advised, and given the shortcomings inherent in the criteria, it is also contrary to the current best use of his criteria.

The next major shortcoming involves the primary assumption the authors make when they state that the purpose of their paper involved “how the concept of subluxation is currently embraced by the chiropractic profession.” I submit that to truly understand the depth and breadth of the subluxation construct as currently embraced by the profession one must begin with a thorough reading of the current editions of the most evidence-based textbooks used in contemporary chiropractic education. The following is a short list of the texts that I believe best represent the subluxation construct as it currently exists in the profession (author or editor and year of publication included): Principles and Practice of Chiropractic (Haldeman, 2005) [9], The Chiropractic Theories: A Textbook of Scientific Research (Leach, 2004) [10], Chiropractic Technique: Principles and Procedures (Peterson and Bergmann, 2002) [11], Foundations of Chiropractic: Subluxation (Gatterman, 2005) [12], and Technique Systems in Chiropractic (Cooperstein and Gleberzon, 2004) [13].

If one were to read these texts it would become very clear that the current state of the chiropractic profession in regards to the SC is not accurately depicted in the paper by Mirtz et al. In essence the authors focused on a very narrow element of the construct, namely the subluxation as a cause of a visceral disease. In reality the current model of the SC has as its focus the concept often described to patients as the “painful sticky joint.” This is identified in Peterson and Bergmann’s Chiropractic Technique as “joint subluxation/dysfunction syndrome” and is associated with local pain, tissue hypersensitivity, decreased joint movement and other local findings [11]. This definition of subluxation is the foundation of their book, a text that has been adopted by no less than 10 of the current chiropractic colleges in the US and many of the programs outside of the States (personal communication, K White, Senior Editor, Elsevier Publishing). Similarly, Leach defines the contemporary version of the SC as spinal “segmental dysfunction” and describes the lesion as having a loss of motion, local tenderness and increased tension in paraspinal muscle [10]. Curiously enough, a permutation of the SC is also identified as “spinal joint dysfunction” by one of Mirtz’s co-authors in the text Handbook of Clinical Chiropractic Care. In his book Wyatt states that “this lesion can cause focal or diffuse spine pain, radiating pain not below the elbow or knee, and/or referred pain simulating visceral disease [14].”
Furthermore, more complex musculoskeletal conditions based on regional spinal joint dysfunctions have been described by Gatterman and her co-contributors [12]. Their text provides a well evidenced clinical approach to patient care based on the SC and includes a categorization and description of various subluxation syndromes. The focus of these syndromes is clearly within the musculoskeletal system and includes cevicogenic headache, thoracic outlet syndrome associated with first rib subluxation, thoracic and costovertebral subluxation syndromes, lumbar facet subluxation syndrome, intervertebral disc syndrome, sacroiliac subluxation syndrome, coccygeal subluxation syndrome, and cevicogenic sympathetic syndrome, among others.
Therefore, as noted above, segmental dysfunction and musculoskeletal oriented subluxation syndromes are the common and well recognized modern permutations of the SC. It is also clear that this musculoskeletal focus is the basis for contemporary clinical practice, as observed by Smith and Carber [15]:

"Most chiropractors typically reported that over 75% of their clinical approach to addressing musculoskeletal or biomechanical disorders such as back pain was “subluxation-based.” Conversely, most chiropractors also reported that less than 20% of their clinical approach was “subluxation-based” for patient complaints deemed to be principally problems with circulation, digestion, or similarly “visceral” in nature."

To return to the paper by Mirtz and colleagues, even if one accepts their findings that to date there was no published epidemiological evidence for a specific subluxation-induced disease, it is obvious their conclusion that the SC “has no clinical applicability” must be rejected as a flawed over generalization given the current musculoskeletal focus of subluxation in regards to patient care. This oversight is particularly puzzling since Mirtz et al cited Smith and Carber’s paper in their article. Unfortunately the advice of Smith and Carber to move beyond the polarized polemics of the past seems to have been missed as well.

The third significant shortcoming by Mirtz et al involved the use of the ACC presidents’ definition of subluxation [16], which itself has serious limitations. In the first case this definition is outdated; in the second it is far too ambiguous to be useful as the basis for such work because it is prone to selective interpretation. Probably the observation that the definition is “beautifully vague and vaguely beautiful” is one of the best things that can be said about it [17]. This is understandable however because it was the result of consensus building and was not intended as a basis for research endeavors. To elucidate, when the position paper on chiropractic was produced by the North American college presidents in the mid 1990s this was seen by many as a remarkable outcome in a land of significant political divide. The subluxation definition was an attempt to bring unity to the profession at a time when this was (and is) sorely needed, and in doing so a definition was created that was as broad and inclusive as possible. As Leach noted, the definition was most appropriately seen as a significant step in the maturation of the profession and a move away from vitalism [10]. Keating et al [3] have identified additional problems with the presidents’ definition, but suffice it to say that as written the definition could encompass virtually all forms of clinical conditions involving a spinal motion segment. However, in the realm of contemporary chiropractic education and practice the presidents’ definition is best interpreted as follows: the spine and pelvis are considered in regards to functional, structural and/or pathoanatomical changes to the intervertebral disc, zygapophyseal, uncovertebral, atlantooccipital, atlantoaxial, atlantoodontal, sacroiliac, sacrococcygial and symphysis pubis articulations and the neurological reactions associated with those changes, the most common of which is nociception. However the representation of the presidents’ definition of subluxation by Mirtz and colleagues is far from this. By choosing to focus on the most tenuous element of the definition (i.e. subluxation as a cause of visceral disease) they have developed a straw man argument in the guise of a questionable narrative literature review. In actuality what the authors have shown is that the presidents’ definition has shortcomings that are easily exposed under academic scrutiny. But in no way can one extend their conclusions to all elements of the SC because these were not thoroughly defined, investigated or reported on, which leads to the next major shortcoming.

A fatal shortcoming of Mirtz et al involved the methods utilized in the literature review itself. Before conclusions can be made regarding whether the SC has clinical applicability a properly performed systematic review would have to be done [18,19]. At the very least this would require actually evaluating the quality of the studies pertaining to Hill’s criteria, which would begin with studies in which both aspects of interest were measured (i.e. the subluxation and some type of disease). Additionally, it would also involve obtaining and assessing the quality of any study in which an association was evaluated between any one of the aspects included in the definition of the SC and any health condition, including those studies which had not addressed Hill’s criteria specifically. The review offered by Mirtz et al clearly does not rise to these standards, and if fact, even minimally accepted standards regarding published literature reviews were not met. Nowhere in their paper is there a description of the total number of “hits” the search terms returned (either in isolation or combination), the effect the inclusion and exclusion criteria had on these hits, or the final tallies of the papers that were included or rejected in the application of these criteria. Reporting this information is common procedure when publishing the results of a literature review [19]. Without it the reader is not able to reproduce the work, consider the quality of the search or assess any biases. Additionally, it is also reasonable to assume that given the contentious nature of the word subluxation contemporary authors (including those outside of chiropractic) are using different terms such as “segmental dysfunction” or “spinal joint dysfunction” to describe the subluxation, which were terms not included in the Mirtz et al literature search. Ultimately it is not possible to accept at face value the result that only four peer-reviewed journal articles exist and were able to be examined per Hill’s criteria. But even if it was accepted (as other authors have noted) that there is a paucity of epidemiological investigations regarding the SC [20,21], then the observation that the subluxation fared poorly in regards to Hill’s criteria is best explained by the fact that the investigations simply have not been done and/or the research investigations haven’t been published. Ultimately the conclusion by Mirtz et al that the subluxation construct is “in the realm of unsupported speculation” cannot be made until it is supported by the findings of a comprehensive and properly performed systematic review and even then any conclusion would have to placed into context relative to the number of high quality studies that have actually been performed; without it their assertion is meaningless if not misleading.
This leaves the last major shortcoming of the work, which is tied directly to the highly evocative nature of the debate involving the subluxation. As stated above, I am of the opinion that the conclusions of the authors are not just flawed, but are harmful. This is because inflammatory conclusions only serve to strengthen the resolve of those who embrace the most speculative aspects of the SC and/or those who view subluxation as their raison d'être and practice within a narrow scope as described by McDonald [22]. Such conclusions make the article prone to being discarded as just another “subluxation bashing” paper designed to humiliate and eliminate narrow scope practitioners. But isn’t this the group that many of us are hoping to influence the most? Is this the best way to encourage a cultural change, especially when considering the number of chiropractors with more moderate views (i.e. the “middle scope practitioners” [15, 22]) who hold a contemporary understanding of the SC and would reject the Mirtz paper on similar grounds?

What makes the conclusions of Mirtz and colleagues particularly reckless however is the reality that journal articles (and their shortcomings) are so quickly and broadly disseminated. Articles in the Journal of Chiropractic and Osteopathy become included in the most important science and health care data bases that exist, such as MEDLINE as accessed through PubMed. It is very clear that perceptions of the chiropractic profession by the public (including current and potential patients, litigants, healthcare policy makers and other healthcare providers) can be directly impacted by our publications. Once published, these papers provide ammunition to chiropractic adversaries at a time when the profession can least enjoy it. I believe there are important lessons to be learned by all parties involved in chiropractic journal publications, and this includes not only authors but also peer-reviewers and journal editors. We are the stewards of this important source of information and we all need to act in a responsible fashion.

The debate regarding the various elements of the SC is obviously important for our patients and our profession. As noted above the majority of patients enter chiropractic offices with musculoskeletal complaints and often this is thought to be associated with some type of painful joint dysfunction. Some patients have also reported success with non-musculoskeletal conditions [23,24] and new patients come to our offices with the hope that they will experience those same benefits. It is clear that there is a lack of published research in this domain and this has been thoughtfully presented by Hass et al as an outcome of the most recent Chiropractic Research Agenda initiative [21]. A contemporary perspective in regards to visceral conditions and the subluxation has also been described by Budgell in which he differentiates between subluxation as a cause of a specific disease (not very likely) and subluxation as a component of functional visceral disorders by virtue of somatoautonomic or other neurophysiological mechanisms (more likely) [12]. Comprehensive reviews of the evidence concerning chiropractic care for non-musculoskeletal conditions by Leach [10] and chapters by Vernon and Sarnat and Budgell [9] provide an excellent contemporary education in this area. Vernon in particular offers an important algorithm for care when patients present with visceral signs and symptoms. Additionally, the work of Hawk et al has shifted the paradigm of chiropractic care for non-musculoskeletal conditions into one focusing on whole system research, which might be more appropriate in some cases [25]. Her work as well as those of others regarding all aspects of chiropractic care has been the focus of the Council on Chiropractic Guidelines and Practice Parameters (CCGPP) and their literature syntheses are important, must read publications [26]. Interestingly, one task yet to be completed by the CCGPP involves a chapter on subluxation, which if written with the same due diligence as the other chapters, should become an excellent resource for the profession.

Finally, I would also submit that segmental dysfunction as a cause of non-musculoskeletal disorders due to reactions within the nervous system are far from having no evidence, much less no clinical applicability. For example, the contemporary version of the subluxation construct includes the well established cauda equina syndrome as a result of severe intervertebral disc disruption, among other things [12]. Additionally, numerous non-musculoskeletal case studies exist as noted by Leach [10] and Sarnat and Budgell [9], and while case studies are one of the weakest forms of clinical evidence, they are evidence nonetheless. Of course causality cannot be determined by case studies, but descriptions of patients who obtained a significant benefit (or harm, as the case may be) are worthy of clinical consideration and further research, and should not be ignored. Also, by maintaining a continually evolving SC as a core component of clinical education and practice the chiropractic profession retains its unique perspective, meanwhile establishing a profession which offers high quality patient care based on the best available evidence. The SC provides an environment of inquiry so that researchers are able to pursue alternative hypotheses in regards to non-musculoskeletal clinical presentations, such as the effect adjusting upper cervical subluxation has on blood pressure [27] or on neck-tongue syndrome [28]. It also creates a model from which to understand mimicry conditions such as pseudo-angina associated with thoracic region segmental dysfunction [29,30].

In my opinion though, what is particularly ripe for investigation are the hypothesized somatoautonomic reflex phenomena associated with the SC. Just as the profession initially focused its research efforts on our most commonly observed musculoskeletal successes (low back pain, neck pain and headache), it now seems prudent to focus some of our resources on the most common non-musculoskeletal presentations. I would offer my clinical observations (and unfortunate experiences as a patient) regarding severe lumbar spinal pain and dysfunction and associated transient constipation as an ideal place to start. It would seem that of all the likely candidates from which to establish a painful joint dysfunction as a cause of visceral dysfunction, this presumed sympathetic nervous system reaction sits at the top the list given its frequency and temporality. But of course, in order for this research to proceed the criteria often identified on television police dramas must first be grappled with: means, motivation and opportunity. I believe we have researchers with enough motivation, but is the profession ready to provide the means and opportunity…or is it going to continue to live in the world of poorly evidenced hypotheses and let the vocal minorities at the extremes of our profession run (or ruin) the debate?

Despite the shortcomings of Mirtz et al’s paper, the examination of the SC in regards to Hill’s criteria is still important because it provides a framework for understanding the most important issues regarding claims of causation and it identifies areas in need of epidemiological research. It also highlights the shortcomings of the ACC presidents’ definition of subluxation and a carefully crafted revision of it appears to be warranted. Lastly, given the continued improvement in chiropractic education and the profession’s textbooks, a chasm has emerged between a contemporary understanding of the subluxation construct and historical notions held by some. Instead of denigrating those beliefs in our journal publications, a concerted effort must be made to continually update our colleagues so that we are able to offer the best casting of our valued profession to our patients and society at large.

Christopher Good DC, MA(Ed)
Professor of Clinical Sciences
University of Bridgeport College of Chiropractic

References
[1] Mirtz TA, Morgan L, Wyatt LH, Greene, L: An Epidemiological Examination of the Subluxation Construct using Hill’s Criteria of Causation. Chiro & Osteo 2009, 17(13).
[2] Good, C: Subluxation Syndromes: A Condition Whose Time Has Come? J of Chiropr Hum, 2004; 11:38-43.
[3] Keating JC, Carlton KH, Grod JP, Perle SM, Sikorski S, Winterstein JF. Subluxation: dogma or science? Chiro & Osteo 2005, 13: 17.
[4] Yoshioka, A. Use of randomization in the Medical Research Council’s clinical trial of streptomycin in pulomonay tuberculosis in the 1940s. BMJ 1998, 317: 1220-3.
[5] Hill AB. The environment and disease: association or causation? Proc R Soc Med 1965, 58: 295-300.
[6] Ward AC. The role of causal criteria in causal inferences: Bradford Hill’s “aspects of association.” Epidemiologic Perspectives & Innovations 2009, 6: 2.
[7] Rothman KJ, Greenland S: Causation and causal inference in epidemiology. Am J Public Health. 2005, 95: S144-S150.
[8] Rothman KJ, Greenland S, Poole C, Lash TL: Casuation and casual inference. In: Modern Epidemiology 3rd edition. Edited by: Rothman KJ, Geenland S, Lash TL. Philadelphia, PA: Lippincott, Williams and Wilkins; 2008:6-31.
[9] Haldeman S (ed): Principles and Practice of Chiropractic. McGraw-Hill; 2005.
[10] Leach RA: The Chiropractic Theories: A Textbook of Scientific Research. Lippincott, Williams and lkins; 2004: 48, 138, 563-566.
[11] Peterson D, Bergmann T: Chiropractic Technique. Mosby: 2002:104.
[12] Gatterman MI: Foundations of Chiropractic: Subluxation. Elsevier-Mosby: 2005:373-556, 563-566, 530-31.
[13] Cooperstein R, Gleberzon BJ: Technique Systems in Chiropractic. Churchill Livingstone: 2004.
[14] Wyatt LH: Handbook of Clinical Chiropractic Care. Jones and Bartlett: 2005:290.
[15] Smith M and Carber LA. Survey of US chiropractor attitudes and behaviors about subluxation. J of Chiropr Hum, 2008, 19-26.
[16] Association of Chiropractic College. A position paper on chiropractic. J Manipulative and Physiol Ther 1996,19: 634-637.
[17] Good C. Creating a common sense of identity during post-graduate and continuing education courses. In: Proceeding from the World Federation of Chiropractic/Association of Chiropractic Colleges’ Education Conference on Professional Identity and Curriculum, World Federation of Chiropractic: 2006:149.
[18] Moher D, Tetzlaff J, Tricco AC, Sampson M, Altman DG. Epidemiology and reporting characteristics of systematic review.. PLoS Med 2007, 4 (3): e78.
[19] Green, B.N., Johnson, C.D. and Adams, A. Writing narrative literature reviews for peer-reviewed journals: secrets of the trade. Journal of Chiropractic Medicine. 2006, 5(6):101-14.
[20] Mootz RD, Shekelle PG, Hansen DT. The politics of policy and research. Topics Clin Chiro. 1995, 2(2):56-70.
[21] Haas M, Bronfort G and Evans RL. Chiropractic clinical research: progress and recommendations. J Manipulative and Physiol Ther. 2006, 29(9):695-706.
[22] McDonald WP (ed). How Chiropractors Think and Practice. Institute for Social Research, Ohio Northern University; 2003.
[23] Hawk C, Long CR and Boulanger KT. Prevalence of non-musculoskeletal complaints in chiropractic practice: report from a practice-based research program. J Manipulative and Physiol Ther. 2001, 24(3):157-69.
[24] Leboeuf-Yde C, Pedersen EN, Bryner P, Cosman D, Hayek R, Meeker WC, Shaik J, Terrazas O, Tucker J, Walsh M. Self-reported non-musculoskeletal responses to chiropractic intervention: a multination survey. J Manipulative Physiol Ther. 2005 Jun, 28(5):294-302.
[25] Hawk C, Khorsan R, Lisi AJ, Ferrance RJ, Evans MW. Chiropractic care for non-musculoskeletal conditions: a systematic review with implications for whole systems research. J Altern Complement Med. 2007, Jun, 13(5):491-512.
[26] The Council on Chiropractic Guidelines and Practice Parameters [http://www.ccgpp.org].
[27] Bakris G, Dickholtz M, Meyer PM, Kravitz G, Avery E, Miller M, Brown J, Woodfield C, Bell B. Atlas Vertebra Realignment and Achievement of Arterial Pressure Goal in Hypertensive Patients: A Pilot Study J Hum Hypertens. 2007 (May), 21(5):347–352.
[28] Borody C. Neck-tongue syndrome. J Manipulative Physiol Ther. 2004 Jun, 27(5):367e6.
[29] Wax CM, Abend DS, Pearson RH. Chest pain and the role of somatic dysfunction. JAOA 1997, 97(6):347-355.
[30] Smith M, Lawrence DJ, and Rowell RM. Management of chest pain: exploring the views and experiences of chiropractors and medical practitioners in a focus group interview. Chiro & Osteo. 2005, 13:18

plain film radiography

Mark Lopes — 2010-03-08T02:56:16Z

In the case studies, there is mention of plain film radiography being considered normal. The description of what views were taken is incomplete. There is a photo of an A-P lumbar view in one case reportedly showing no significant findings. The MRI reportedly picked up the malignancy. The MRI shown was a lateral view. Was there a lateral plain film taken? The point of the article seems to be that not taking a plain film initially didn't alter the outcome. The patients apparently died, but if a lateral was not taken as would be standard practice if one is to expose an area (taking opposing views of the area is generally accepted as standard) how are we to know the lateral plain film would not have shown the malignancy? The second case was similar, only showing an A-P chest view. Was a lateral taken? I think it was incomplete not to at least discuss whether or not laterals were taken in order to make the point that taking the plain film did not alter the course of care in either case.

Subluxation, evidence-based medicine and epidemiology. Response to comments made by Drs. Demetrious and Hart

Timothy Mirtz — 2010-01-07T03:51:43Z

We wish to thank Drs. James Demetrious and John Hart for their thoughtful Letters to the Editor concerning our recent paper “An epidemiological examination of the subluxation construct using Hill’s criteria of causation”[1].

Dr. Demetrious referred us to the paper by Phillips and Goodman entitled, “The missed lessons of Sir Austin Bradford Hill" [2]. We wish to point out that we specifically used the Phillips reference in our paper under the subheading “Limitations to utilizing Hill's Criteria” (Ref #32). Notwithstanding, Phillips and Goodman’s [2] concerns about “statistical significance” and “precision” are irrelevant in the case of subluxation because we simply have no credible data upon which to perform measures of “statistical significance” or “precision”. In our paper we readily agreed with Phillips and Goodman [2] that belief in “. . . a causal relationship is not sufficient to suggest action should be taken.” Something more than mere belief is needed. Unfortunately, in the case of subluxation, chiropractic has not much more than belief to offer. Furthermore, Phillips and Goodman [2] also noted that “Association does not prove causation (other evidence must be considered)”. We also wish to point out that merely discussing subluxation from anecdotal experience and case studies does not mean that a subluxation was actually encountered.

In essence we believe Dr. Demetrious is pointing to Phillips and Goodman’s [2] specific statement: Regulators often fail to act because we have not yet statistically "proven" an association between an exposure and a disease, even when there is enough evidence to strongly suspect a causal relationship.

Granted, our paper does not delve into or consider health policy formulation. But the fact remains that non-chiropractic policy regulators will eventually make decisions about subluxation based upon the best available scientific evidence. After 114 years of chiropractors making claims about the significance of subluxation as a causal factor for sub-optimal health and disease formation there has not been produced sufficient evidence to substantiate such bold claims.

The extant evidence is insufficient to strongly suspect a causal relationship between subluxation and disease and consequently to even go further into the realm of statistical significance seems unnecessary. In other words, the latter portion of the Phillips and Goodman [2] statement has not been met by the chiropractic profession.

We predict that our review will produce fear and apprehension by chiropractors. We also believe that chiropractors who are disenchanted with our findings will be calling upon Phillips and Goodman’s [2] work as “evidence” that there is a subluxation cause and effect association.

Dr. Hart believes that we somehow overlooked literature that would qualify for some of Hill’s criteria. Dr. Hart would like us to believe that the results of a survey of chiropractors (who believe in the subluxation construct) is sufficient evidence to conclude that subluxation can meet the consistency criteria. We respectfully refer Dr. Hart to our paper [1] that stated: For the chiropractic subluxation to meet these criteria it (subluxation) would have to be found repeatedly in different persons, places, times, and circumstances. In the case of a clinical condition, the subluxation would have to be consistently found with the clinical condition. To date there has not been a study that has found the subluxation in any one population (gender, race, ethnicity, age).

The study that Dr. Hart refers to [3] does not satisfy that there is a positive health outcome consistent with any variable such as gender, race, ethnicity or age. Thus the study [3] that Dr. Hart alludes to does not qualify as meeting the consistency criteria.

Dr. Hart also believes that given the literature on patients who report improvement after, not before, adjustment of subluxation that the criterion of temporality would seem to be satisfied. Dr. Hart cites references he believes meet the temporality criterion. For temporality to be met the subluxation must always precede the clinical condition for a true cause and effect scenario to take place. For example, Dr. Hart lists studies that are suggestive that subluxation is found in Bell's palsy, myasthenia gravis vertigo and tinnitus, diabetes, epilepsy and ADHD along with others from his list of references. These studies did not find the subluxation as causal of these clinical conditions. There are other pathophysiological processes that can easily be explanatory. These conditions have other, more scientifically-derived, etiologies.

It is worth noting that most manual medicine practitioners could deliver spinal manipulation to such a case without having to acknowledge that a subluxation was present or not. We find it interesting that only some chiropractors can find a subluxation associated with such pathological states whereas other chiropractors and health professionals do not. Furthermore, what Dr. Hart has provided are merely case studies which in the evidence hierarchy sits low on the spectrum of evidence. Case studies are merely capable of generating an hypothesis and do not prove causation or cure.

Dr. Hart believes that the subluxation model adequately satisfies the biological plausibility criterion. The biological plausibility criterion asks the question “does a pathophysiologic model of how the exposure could cause the disease make sense?” [1] In other words, does the subluxation as a pathophysiologic model of having a subluxation being a causal factor of disease make sense? We suggest that it does not make sense. Nansel and Szlazak [4] noted: it is extremely important to keep in mind that all of the "somato-visceral disease" theories and models put forth over the years, regardless of their lack of biological tenability, have also suffered from a common central premise, that is, that the patients involved in these rather "miraculous" clinical situations were really suffering from true visceral disease in the first place!

Nansel and Szlazak [4] noted: we are aware of not a single appropriately controlled study that has convincingly established that spinal manipulation represents a valid curative strategy for the treatment of any true visceral disease, even though scientifically unsubstantiated claims of such therapeutic efficacy continue to be all too prevalent throughout the chiropractic profession.

After 14 years since this seminal paper was published, we do not know of any study that has established spinal manipulation as a valid curative strategy. We do know that unsubstantiated claims of therapeutic efficacy continue to plague the chiropractic profession. It is our opinion that the ACC Paradigm [5] still lends itself to such claims of therapeutic efficacy in their own definition of a subluxation.

Furthermore, we believe that the non-biological plausibility of the subluxation, seen in the ACC Paradigm, is further explained by Nansel and Slazek [4]. They suggested that: there is not the slightest suggestion that patients suffering from severe, primary, mechanical low back pain, for instance, are more prone to develop higher incidences of prostate or testicular carcinoma, colitis, ovarian cysts, endometriosis, pancreatitis, appendicitis, diabetes mellitus or any other category of regionally or segmentally related organ disease.

We believe that this explanation alone is suggestive of the folly of the subluxation as a biologically plausible explanation as described by the ACC Paradigm [5]. Thus, the biological plausibility is unfounded. What Dr. Hart has brought forward are individual aspects (the five components of the subluxation i.e. kinesiopathology, neuropathology, etc) and suggests that each of these are somehow biologically plausible. By themselves, we agree that they have a level of biological plausibility. However, for a subluxation to be a true entity it should consist of all five components. And this is where the model, in our opinion, falls apart. There simply is no evidence whatsoever suggestive of this subluxation construct. In addition, the mentioning of the five components of subluxation yet detailing only part of the components does not make a subluxation. In summary, the notional entity known as subluxation (for it to be a subluxation) should have all the five components available. Furthermore, such an entity would have to meet cause and effect criteria to be a putative clinical entity worthy of intervention. Our review found no evidence of this.

Dr. Hart laments that we missed an opportunity to point out what it would take to adequately satisfy the criteria of causation. The purpose of this examination was to review the current evidence on the epidemiology of the subluxation construct and to evaluate the subluxation by applying epidemiologic criteria for its significance as a causal factor [1]. Thus our purpose was not in research design or methodology of examining the subluxation. We leave it to the subluxation advocates to address this.

As well, we must point out that we did not intentionally avoid the EBM principles in our paper. The purpose of the paper was to examine the subluxation construct using criteria of causation i.e. Hill’s Criteria. Dr. Demetrious should know that the EBM paradigm was developed by epidemiologists. A thorough reading of Sackett’s work [6] specifically notes the value of epidemiological principles.

However, Dr. Demetrious correctly noted the thoughts by Sackett et al [6], namely:
• Evidence based medicine is the conscientious, explicit, and judicious use of current best evidence.
• The practice of evidence based medicine means integrating individual clinical expertise with the best available external clinical evidence.
• Evidence based medicine is not restricted to randomised trials and meta-analyses. It involves tracking down the best external evidence.

We emphatically agree with these views and believe we are quite familiar with the EBM paradigm. Nonetheless, we specifically point out that every single one of these points involves the use of actual evidence. The whole focus of our paper was to examine the evidence and report the findings. These findings demonstrate an absence of any coherent, credible, objective evidence that will support the subluxation construct as it relates to the ACC Paradigm [5]. Simply put, the evidence is simply not there.

It is true that we concluded that the subluxation construct has no valid clinical applicability as Dr. Hart asserts. However, Dr. Hart suggests that we failed to provide hard data to support such a conclusion. We stand by our conclusion based on the lack of findings in the literature. If the subluxation was a valid clinical entity the literature would bear this out. Thus the only conclusion one can draw is that subluxation is a suspect clinical entity.

As well, Drs. Hart and Demetrious have suggested that we have ignored the axiom that absence of evidence is not necessarily evidence of absence. We believe that this comment has been over-utilized by chiropractors to the point of being cringe-worthy. We also believe it is a shield to cover the chiropractic profession and is used as a measure of our collective lack of evidence. Our paper, although preliminary, is illustrative of the “proof of absence.” The burden of proof rests with the chiropractic profession.

We wish to leave this argument with a quote from Charles Darwin that we feel is appropriate to the subluxation debate: “Ignorance more frequently begets confidence than does knowledge.”

Again, we wish to thank Drs. Hart and Demetrious for taking the time to critique of our work and we look forward to seeing new credible research that explores the theoretical construct that is subluxation.

Timothy Mirtz DC, PhD, CHES, CAPE
Lon Morgan DC, DABCO
Larry Wyatt DC, DACBR
Leon Greene PhD

References

[1] Mirtz TA, Morgan L, Wyatt LH, Greene L. An epidemiological examination of the subluxation construct using Hill's criteria of causation. Chiropractic and Osteopathy 2009; 17:13.

[2] Phillips CV, Goodman KJ. The mixed lessons of Sir Austin Bradford Hill. Epidemiol Perspect Innov 2004;1:1-5.

[3] McDonald WP, Durkin KF, Pfefer M. How chiropractors think and practice. The survey of North American chiropractors. Seminars in Integrative Medicine 2004; 2(3):92-98.

[4] Nansel D, Szlazak M. Somatic dysfunction and the phenomenon of visceral disease simulation: a probable explanation for the apparent effectiveness of somatic therapy in patients presumed to be suffering from true visceral disease. J Manipulative Physiol Ther. 1995;18(6):379-97.

[5] Association of Chiropractic Colleges. A position paper on chiropractic. J Manipulative Physiol Ther 1996;19:634-637.

[6] Sackett, DL. Straus SD, Richardson WS, Rosenberg W, Haynes RB. Evidence-based Medicine: How to Practice and Teach EBM. 2nd Edition. 2000. Churchill-Livingstone. Edinburgh.