Background

The concept of vertebral subluxation – also called chiropractic subluxation or the vertebral subluxation complex – remains controversial, even within the chiropractic community [1,2,3,4,5]. The theory of vertebral subluxation, originally posited by D.D. Palmer at the turn of the century, has played a central role in the development of the practice of chiropractic [1, 5]. However, a considerable amount of research and commentary – often produced by the chiropractic community – has highlighted that there is no science to support the concept of vertebral subluxation [1,2,3,4, 6]. The concept is scientifically implausible, and there is no evidence to support the idea that it is associated with any ailment or the promotion of general health [1,2,3,4,5]. As such, in some jurisdictions, chiropractic organizations have taken a stand against vertebral subluxation. In 2010, for example, the General Chiropractic council in the UK stated, “The chiropractic vertebral subluxation complex is an historical concept but it remains a theoretical model. It is not supported by any clinical research evidence that would allow claims to be made that it is the cause of disease” [7]. Similarly, in 2015, various international bodies, including chiropractic schools, put forward a position statement that declared “the teaching of vertebral subluxation complex as a vitalistic construct that claims that it is the cause of disease is unsupported by evidence. Its inclusion in a modern chiropractic curriculum in anything other than an historical context is therefore inappropriate and unnecessary” [8]. The Alberta College and Association of Chiropractor’s 2008 position statement on the “Definition of Subluxation” makes no reference to vertebral subluxation but states that “the ACAC acknowledges and understands that the definition of a chiropractic subluxation may be ‘different from the current medical definition, in which subluxation is a significant structural displacement, and therefore visible on static imaging studies’” [9].

Indeed, divisions are evident among chiropractors over the role of subluxation and its related health problems [1, 5, 10]. The chiropractic community differs greatly in how subluxations are to be defined, and there currently exists no “gold standard” in the detection of subluxation [3, 11]. Furthermore, research has shown that in chiropractic education and training confusion exists among chiropractic students regarding the role subluxations play in chiropractic and whether these understandings of subluxation align with or contrast with an evidence-based approach [12, 13].

Despite the emerging consensus about the lack of science to support the subluxation theory, many chiropractors continue to embrace subluxation and offer services to patients based on its existence [1, 5]. The objective of this study was to examine the use of “subluxation” on the websites of Alberta health clinics offering chiropractic services. We examined how often the unscientific concept is promoted and used to market chiropractic services. We also sought to analyze the discourse surrounding vertebral subluxation, such as whether it was linked to specific medical conditions and used in marketing chiropractic services to particular demographics, including children.

Methods

We used the Canadian Chiropractic Associations’ website [14] to obtain a list of health clinics offering chiropractic in the province of Alberta. On the 4th and 5th of January 2018, we used the “Find a chiro” search engine available on the website and recorded all clinics listed when searching for “Alberta”. This list totaled 493 clinics. We then searched for each of the 493 clinics using Google in order to match the clinic with a URL. In total we found a URL for 369 of the 493 clinics. These 369 clinics had a total of 324 URLs. This was because some clinics had multiple locations, or fell under an umbrella company, which shared the same URL. The two largest of these cases included one URL for 19 different clinics [15], and one URL for seven clinics [16].

We the inputted the formula: subluxation site: [clinic URL] into the Google Chrome search engine to capture all cases where “subluxation” appeared on the website. In cases where more than 10 page links appeared on a URL, we opened only the first 10 appearing on the search results. We then asked the following questions regarding the use of the “subluxation” content:

  1. 1.

    Is a theory of subluxation described (brought up and/or discussed in a health-related context)? If so, how is subluxation described?

  2. 2.

    Are health problems or general health improvements (use as a prevention or “wellness” strategy, increased energy, etc.) linked to “subluxation” (including: spine subluxation, vertebral subluxation, subluxation complex)?

  3. 3.

    Is “subluxation” theory critiqued (i.e. discredited, described as outdated or problematic, etc.)?

  4. 4.

    Is “subluxation” mentioned on the website in an alternative manner from that already coded?

  5. 5.

    Are any particular demographics focused on when discussing subluxation?

While coding, we observed some discourse that appeared to working towards creating anxiety or fear in (potential) clients. Due to its subjective nature, discourse of this sort was not formally quantified but some examples were captured and included in the results in order to highlight the presence of this problematic marketing.

To ensure validity, in all cases where “subluxation” appeared on a website, a screen shot of the discourse was taken with the clinic’s URL appearing in the URL bar at the top of the Google Chrome browser. In cases where subluxation appeared numerous times on the same page, we took a screen shot of each use. After our analysis, a researcher external to the project assessed all coding with respect to question #1. Any discrepancies were rechecked by the original coder.

Results

Theory of vertebral subluxation

Of the 369 clinics, 159 (43%) had websites containing the word “subluxation”, and 121 clinics’ websites (33%) present a theory of vertebral subluxation. That is, subluxation was described as a misalignment in the spine causing interference between the brain and body, and/or as having an impact on the nervous system or organ system functioning, and/or as affecting overall health or optimal health. Examples of these uses are displayed in Table 1. One additional website presented the vertebral subluxation theory but solely in the context of pets. Sixteen clinic websites (4%) mention “subluxation” in a variety of manners but do not clearly posit a theory of chiropractic vertebral subluxation.

Table 1 Ten text examples of clinic websites presenting a theory of chiropractic vertebral subluxation
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Health problems or health improvements linked to subluxation

A wide range of health problems or general health improvements were linked to vertebral subluxation and are displayed in Table 2. It was not our objective to quantify the presence of each health topic. The health problems and improvements mentioned are extensive, including serious diseases and potential organ malfunction, a wide-range of child specific health problems such as ADHD, bed-wetting, and colic, and a range of other issues such as stomach and digestive problems, asthma, allergies, ear infections and blood pressure. In addition to the commonly expressed health issue of “nerve interference” (also called “nerve irritation” or “impaired nerve functioning”, etc.), other issues were raised such as “spinal decay” or “spinal degeneration”. It was also common for websites to state that uncorrected subluxations prevent a body from functioning “optimally”, and that a suboptimal body state will struggle to heal itself.

Table 2 Health problems and health improvements linked to chiropractic vertebral subluxation
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Critiques of subluxation

There was only one website which outlined a somewhat critical perspective of subluxation. The text on this website, under the heading “Information for MDs” and the subheading “Education” read: “CMCC is Canada’s only English-speaking chiropractic college; it teaches an evidence-based medicine paradigm, as opposed to the traditional vertebral subluxation model sometimes taught in the United States” [28].

Other mentions of “subluxation”

A total of 20 websites (5%) included the use “subluxation” in an alternative context. These included “subluxation” as the name of journal, a heading or subheading for a link, the name of a machine, the name of a process in a clinic (“the subluxation station”), or as part of a glossary.

Particular demographics

A notable trend evident in the discourse was the marketing of subluxation for children. In total, there were 29 clinic websites (8%) marketing chiropractic for children (including newborns, infants, toddlers, etc.) when discussing subluxation. Table 2 presents the subluxation-related health issues for children, and Table 3 provides examples of the marketing for children.

Table 3 Text examples of clinic websites marketing chiropractic for children in the context of subluxation
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Fear-creating rhetoric in the subluxation discourse

There were three additional trends present in the subluxation discourse on the websites, which could be seen as an attempt to leverage fear. The first were numerous cases where subluxations were presented as asymptomatic (e.g. “Some subluxations may seem to cause no obvious symptoms”; “Pain and symptoms are a bad way to judge if you have subluxations or not”; “Individuals who are not currently experiencing pain or other discomfort are not necessarily ‘subluxation free’” etc.). The second included cases where subluxations were reportedly caused, or potentially caused by: concussions; whiplash (e.g. in car accidents); traumatic “physical causes” including “trauma to the body, repetitive motions affecting the spine, bad postural habits, improper workstation habits and design, and weak or imbalanced spinal musculature”; “Chemical causes” including “poor dietary and nutritional practices, drug and alcohol use and abuse, and the ingestion of chemical toxins in the foods we eat, air we breathe, and water we drink”; “emotional causes” such as stress or “stress management skills”, etc. These types of discourse were often coupled with the notion that only chiropractors are able to identify and correct subluxations and that regular checkups should take place. Lastly, the third trend were cases where subluxations were explicitly described as fatal, a “threat” or as “detrimental to health.” See Table 4 for examples:

Table 4 Fear-creating rhetoric on clinic websites
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Discussion

Our analysis shows that the marketing of chiropractic services on the basis of vertebral subluxation is undertaken by nearly a third of clinics in Alberta that have a working website. Considering that we could not find a URL for more than 120 websites, it is likely that additional clinics in the province align their practices with notions of vertebral subluxation. At least in Alberta, vertebral subluxation is adopted by a significant number of clinics. This is not a fringe issue. Rather, it appears central to the practice of a substantial number of clinics.

The health ailments and/or health improvements linked to the vertebral subluxation discourse on the websites are wide-ranging (see Table 2). While quantifying the presence of these subluxation-related health topics fell outside of the scope of this study, a lack of consistency across the clinics was observed. For example, some clinics associate subluxation with diseases like prostate cancer, MS or Parkinson’s disease, others with pregnancy and fetus development, and others with stomach issues, autism, ADD/ADHD or hormonal imbalances. Not all of the clinics’ websites include the marketing of chiropractic for newborns, infants and children, but some do.

Overall, this analysis provides insight into the degree to which chiropractic services are science-based, and raises interesting questions about regulation. Currently, chiropractic is a self-regulated profession in Canada. If the profession claims to be science-based, self-regulating chiropractic colleges should consider whether it is appropriate to discuss subluxation in an unscientific manner on their websites. Conversely, if these colleges have no issue with the kinds of subluxation-related discourse presented here, they should make official statements declaring this position – at which point legislators could consider what this means in the context of health policy and self-regulation. In the Alberta College and Association of Chiropractor’s 2008 position statement “Definition of Subluxation”, it reads, “The ACAC regulates the chiropractic profession in Alberta under the Health Professions Act. The ACAC is dedicated to regulating the chiropractic profession in a manner that supports quality care and upholds public trust; as well as furthering awareness and understanding of the benefits of chiropractic care” [9]. To what degree does the discourse presented here align or contrast with this statement? For example, Canadian paediatricians have raised concerns about the marketing of chiropractic to children [40], and The Canadian Pediatric Society states that “parents should be made aware that there is a lack of substantiated evidence for the theory of subluxated vertebrae as the causality for illness in children” [41]. This study identified 29 clinics marketing chiropractic for children solely in the context of subluxation discourse.

An extensive amount of research has highlighted the problematic marketing claims by chiropractic clinics from numerous perspectives [42, 43]. Some research has even raised the issue of appealing to fear in the context of chiropractic [44]. This study found rhetoric that would support those concerns, including discourse about potentially dangerous subluxations, which are potentially asymptomatic, and which may be caused by accidents, “poor dietary and nutritional practices”, “sitting”, “toxins” and/or “stress”. Furthermore, targeting parents with young children, in the process of having children, having recently been in an accident or suffering from a concussion, would certainly seem to be working contrary to the ACAC’s mandate of “regulating the chiropractic profession in a manner that supports quality care and upholds public trust” [39]. It is hoped that regulatory bodies will recognize these types of discourse as problematic and will act accordingly.

Limitations

There were clinics in the province for which no URL could be found using the Google search engine. It is possible that the clinics without URLs present and/or align themselves to a perspective of vertebral subluxations differing from the trends we observed in our study. This study only examined the representations on clinic websites. We don’t know what information patients are provided at the relevant clinics. Also, this study identified 29 clinics marketing chiropractic for children solely in the context of subluxation discourse. It is possible that more clinics are marketing – and perhaps aggressively marketing – chiropractic for children.

Conclusion

Based on the controversy surrounding vertebral subluxation, the substantial number of clinic websites in Alberta aligning their practice with vertebral subluxation should receive attention from relevant regulatory bodies. Corresponding regulatory bodies should act accordingly to determine which actions should be taken to clarify the numerous issues raised in this study.