Straight chiropractors adhere to the philosophical principles set forth by D. D. and B. J. Palmer, and retain metaphysical definitions and vitalistic qualities. Straight chiropractors believe that vertebral subluxation leads to interference with an "innate intelligence" exerted via the human nervous system and is a primary underlying risk factor for many diseases. Straights view the medical diagnosis of patient complaints, which they consider to be the "secondary effects" of subluxations, to be unnecessary for chiropractic treatment. Thus, straight chiropractors are concerned primarily with the detection and correction of vertebral subluxation via adjustment and do not "mix" other types of therapies into their practice style. Their philosophy and explanations are metaphysical in nature and they prefer to use traditional chiropractic lexicon terminology such as "perform spinal analysis", "detect subluxation", "correct with adjustment". They prefer to remain separate and distinct from mainstream health care. Although considered the minority group, "they have been able to transform their status as purists and heirs of the lineage into influence dramatically out of proportion to their numbers."
Mixer chiropractors "mix" diagnostic and treatment approaches from chiropractic, medical or osteopathic viewpoints and make up the majority of chiropractors. Unlike straight chiropractors, mixers believe subluxation is one of many causes of disease, and hence they tend to be open to mainstream medicine. Many of them incorporate mainstream medical diagnostics and employ conventional treatments including techniques of physical therapy such as exercise, stretching, massage, ice packs, electrical muscle stimulation, therapeutic ultrasound, and moist heat. Some mixers also use techniques from alternative medicine, including nutritional supplements, acupuncture, homeopathy, herbal remedies, and biofeedback.
Although mixers are the majority group, many of them retain belief in vertebral subluxation as shown in a 2003 survey of 1,100 North American chiropractors, which found that 88 percent wanted to retain the term "vertebral subluxation complex", and that when asked to estimate the percent of disorders of internal organs that subluxation significantly contributes to, the mean response was 62 percent. A 2008 survey of 6,000 American chiropractors demonstrated that most chiropractors seem to believe that a subluxation-based clinical approach may be of limited utility for addressing visceral disorders, and greatly favored non-subluxation-based clinical approaches for such conditions. The same survey showed that most chiropractors generally believed that the majority of their clinical approach for addressing musculoskeletal/biomechanical disorders such as back pain was based on subluxation. Chiropractors often offer conventional therapies such as physical therapy and lifestyle counseling, and it may for the lay person be difficult to distinguish the unscientific from the scientific.