In November of 2017, Chiropractic and Manual Therapies issued a call for papers under the common theme “What is Chiropractic?”. The motivation for the thematic series was to help define chiropractic better to stakeholders inside and outside of the profession. The need for the thematic series was a perceived confusion about what chiropractic is, what chiropractors do, and how they contribute to the health and well-being of patients [1] in spite of official definitions such as by the World Federation of Chiropractic: Chiropractic is a health profession concerned with the diagnosis, treatment and prevention of mechanical disorders of the musculoskeletal system, and the effects of these disorders on the function of the nervous system and general health. There is an emphasis on manual treatments including spinal adjustment and other joint and soft-tissue manipulation [2]. Two years later, 18 papers have been published in the series, and it is time to take stock and examine what we have learned through this initiative.

Main text

We have grouped the published papers in the thematic series under three headings and summarize them below. An overview of aims and conclusions of papers in this series is provided in Table 1.

Table 1 Aims and conclusions of papers published in the series What is chiropractic?

Papers describing the chiropractic profession and chiropractic practice

The overall global view of the chiropractic profession was provided in two articles. Stochkendahl et al. provided a global view of the chiropractic workforce and concluded that chiropractors are present in 90 of 193 United Nations member nations with the highest prevalence in high-income countries [3]. Although chiropractors are legally recognized in 75% of those countries, and chiropractic treatment is fully or partially subsidized by national healthcare systems in around 50%, in some countries chiropractic does not fall under any law or may even be illegal [3]. Beliveau et al. reviewed 52 studies dealing with utilization of chiropractic and found that, generally, utilization was highly variable and population dependent, with no clear change in utilization of chiropractors globally between 1980 and 2015 [4]. They found that the typical chiropractic patient is seeking care for a musculoskeletal problem, most commonly low back pain (50%) and neck pain (23%), is female, middle-aged and employed [4]. Although there is some variation in practice styles, most people seeking care from chiropractors will receive spinal manipulation with around one third also receiving patient education, exercises and soft-tissue therapy [4].

There is an increasing body of literature describing chiropractors in interprofessional collaborations. Mior et al. reviewed literature dealing with chiropractors functioning in the health services of armed forces mainly from the US, Canada and Australia [5]. Stochkendahl et al. found that in the Scandinavian context, chiropractors can fulfil a key role in management of sickness absence and in work disability prevention both informally and as part of system-supported pathways [6, 7]. Another example of chiropractors functioning in interprofessional collaboration was provided by Wirth et al. who reported on outcomes and trajectories of patients referred from a surgical department to chiropractic care [8]. In these settings, chiropractors frequently work alongside or in collaboration with other providers, and Salsbury et al. reported, based on a qualitative stakeholder analysis, that in order to be successful in multidisciplinary teams, chiropractors should be good clinicians, practice according to evidence, be communicative and be supportive of patient’s emotional journeys during care and rehabilitation [9].

Four articles dealt with different elements of chiropractic practice. Axén et al. systematically reviewed evidence pertaining to chiropractic maintenance care and concluded that significant advances had been made in recent decades regarding what maintenance care is, when it should be applied, and what outcomes to expect [10]. Jenkins et al. reviewed practice guidelines dealing with use of spinal x-ray in chiropractic practice and concluded that routine use of x-ray is not in accordance with current evidence and practice guidelines [11]. Hansen et al. reported that chiropractors (at least in Denmark), when surveyed, commonly reported work-related physical acute or overuse injuries in the low back, wrist, thumb and shoulder, but were very satisfied with their job and had a good psychosocial work environment [12]. Gíslason et al., in a survey of chiropractors in Europe, showed that around one fifth identified themselves with an “unorthodox” description of chiropractic care, and that this group were associated with a higher use of x-rays, higher patient visits, absence of differential diagnostic approaches, and less favorable views regarding the benefits of vaccination [13].

Two papers reported on issues relating to education of chiropractors. Innes et al. compared accreditation standards from the Councils of Chiropractic Education between 2010 and 2016 and found that while there had been a move towards a focus on musculoskeletal care, mention of competencies in appraising scientific evidence and evidence-based practice had been removed from the criteria [14]. Funk et al. searched websites of 46 chiropractic educational programs in order to identify and count the mention of the term subluxation, and found that it is much more prevalent in descriptions of US-based educational institutions, and in fact the mention of subluxation had increased between 2011 and 2017 [15].

Papers describing new initiatives and developments in the chiropractic profession

Adams et al. described the aims, core principles, and methodology for the Chiropractic Academy for Research Leadership (CARL). CARL aims to bring together a global network of early career researchers in chiropractic in a global network [16]. Côté et al. described a chiropractic rehabilitation competency framework that was developed by the World Federation of Chiropractic Disability and rehabilitation Committee [17].

Discussion and debate papers

The final group of papers centered on debates and discussions within chiropractic and their implications for professional unity and legitimacy. Coulter et al. described and discussed the research crisis in research in complementary and alternative medicine, with a focus on chiropractic, and suggested ways to advance this research endeavor [18]. Leboeuf-Yde et al. compared the chiropractic profession with an unhappy marriage between practitioners on a continuum from evidence-based, with a focus on management of musculoskeletal disorders, to conservative and vitalistic, with a focus on addressing subluxations to influence the nervous system. These authors suggested that it may be time to openly discuss separation or divorce so that the two fractions can pursue a separate future [19]. Strahinjevich and Simpson also targeted the schism between the evidence-oriented and the vitalistic groups in chiropractic as seen through the eyes of a first-year student, and discussed both the historic background for this and possible ways forward [20].


This commentary brings the 2017–2019 series What is Chiropractic? to a close. The series will remain open to including future articles, if relevant; this commentary provides a summary of the articles officially included in the series that have been published to date. When we made this call for papers in forming the thematic series, we were optimistic that we would energize the researchers in the profession to answer this question. The 18 papers have contributed significantly to a better understanding of what chiropractic is, where chiropractors practice and function, who seeks their care, what chiropractors do, and how they interact with other healthcare professionals. The series has not contributed with new data on effectiveness of the interventions chiropractors routinely apply to their patients; however, a casual search in PubMed using the search terms chiropractic or chiropractor for 2018 and 2019 identified over 700 papers, so clearly many scientific papers pertaining to chiropractic have been published in this and other journals alongside this series. Chiropractic and Manual Therapies is an open access journal, and papers in the series have been read widely with over 63,000 downloads (range 978 [18] – 15,000 [19]) and significant activity on social media.

Papers in this series have again revealed deeply rooted disagreements within the chiropractic profession about what chiropractic is, and what it should be, as a profession [13, 19, 20], as well as disagreements and variation in relation to education of chiropractors [14, 15] and chiropractic clinical practice [11]. In our opinion, it is ironic that while chiropractic has a strong presence in large parts of the world [3], is taking on increasingly important roles in disability prevention [6, 7, 17], in the military [5] and in interprofessional care [8] as well as growing research capacity [16], discussions about fundamental values and direction of the profession are unresolved. This unresolved issue creates confusion for stakeholders and threatens to impede professionalization and cultural authority. If chiropractors are to remain relevant in today’s evidence-based healthcare environment, there is an urgent need to agree on, and further describe, what chiropractic is, what chiropractors do and importantly to provide evidence for value of these activities to patients and societies.