Table 1 The nine chiropractic-related terms searched for and their definitions [32,33,34,35,36,37,38,39,40,41,42]

Subluxation

A chiropractic concept used to describe the misalignment of a vertebra thereby applying pressure to surrounding nerves which cause eventual disease [32]

Adjust(-ing/-ment) and manipulate(-ion)

Chiropractic adjustment has been defined as a form of a manual technique administered to a joint of the spine or any other body part, through which a controlled force is used or a low amplitude, high velocity manual thrust to a motion segment or joint [33]

Holism(-tic)

Holism is the philosophy which states that many parts of a whole are so interrelated that they cannot exist individualistically [34]. An understanding of holism within health care is concerned with complete systems rather than with the analysis of, treatment of, or dissection into parts. Holism (-tic) is also not an exclusive chiropractic-related term and is an approach that involves the physical, mental and spiritual well-being of a patient [35, 36]

Alignment

The historical chiropractic rationale was to visualise the chiropractic subluxation, defined at the time as a ‘bone out of place’, irritating a nerve, and as a result causing disease. This model, often using radiography for the so-called diagnosis, has survived in some parts of the chiropractic profession, despite it lacking evidence or clinical validity [28]

Vital(-ism/-istic)

Vitalism refers to the theory that all living organisms are sustained by a vital life force that is both separate from and greater than normal physical or chemical forces. There are many ways of expressing this life force, including Qi, energy, yin-yang, universal intelligence, or innate intelligence [37]. Vitalism within the chiropractic context can be broken down into two sections: universal and individual and is the idea that a vertebra out of place (i.e. the chiropractic ‘subluxation’) is interrupting the flow of vital energy (innate intelligence) within the body and is the cause of disease or pain in the body [38, 39]

Innate Intelligence

Innate intelligence represents the force that restores health and energy within the body [38, 39] in the chiropractic vitalist background. The vitalist paradigm is an unscientific ideology that is unrecognized by other mainstream medical health professions [40]

Wellness

Wellness-based chiropractic, a form of vitalism, proposes an all-inclusive scope of practice and believes in the ability to address all features of an individual’s health that go beyond the bodily symptomatology and include passionate, mystical and mental aspects of life [41]. Wellness, in this sense, is an ideology that does not align with the mainstream public health definition of wellness that describes healthy life choices for improved mental and physical outcomes [30, 42]