Chiropractic care is a popular form of manual therapy sought by millions for relief from musculoskeletal pain, yet it remains one of the most controversial healthcare professions. This duality—widespread public acceptance contrasted with strong skepticism from the scientific and medical communities—creates a polarizing public perception. The division stems from a complex history, philosophical roots that clash with modern biology, ongoing debates about scientific evidence, and serious, albeit rare, safety concerns. Examining these factors reveals why chiropractic, despite its mainstream presence, continues to be intensely criticized and rejected by many.
Foundational Concepts and Historical Separation from Mainstream Medicine
The controversy surrounding chiropractic begins with its founding in 1895 by Daniel David Palmer, who positioned the practice as fundamentally separate from conventional medicine. Palmer established the profession on the principle of “Vitalism,” which posits that a non-physical, innate intelligence controls all biological functions and healing. This philosophy asserts that all disease results from interference with the flow of this innate intelligence through the nervous system.
The mechanism for this interference was defined as the “vertebral subluxation complex,” a concept central to early chiropractic theory. Historically, this subluxation was described as a slight misalignment of a spinal vertebra that impinges on nerves, causing disease throughout the body. This philosophical foundation, claiming that spinal adjustments can cure ailments far beyond musculoskeletal issues, immediately separated the profession from the emerging science-based approach of medicine.
The term “subluxation” is a major point of contention. While the medical definition refers to a partial joint dislocation visible on imaging, the chiropractic concept refers to a subtle, functional entity that allegedly affects nervous system function. This core, historically vitalistic concept is not supported by contemporary anatomy or physiology and led to a century of scientific and professional isolation.
The Scientific Evidence Gap and Pseudoscience Accusations
Modern skepticism is primarily fueled by the lack of high-quality scientific evidence for many historical claims associated with chiropractic practice. While there is moderate scientific support for spinal manipulation as an effective treatment for acute and chronic low back pain, neck pain, and some types of headaches, the evidence for other conditions is notably weak. Claims that adjustments can treat non-musculoskeletal issues like asthma, infections, or infant colic lack the rigorous, placebo-controlled data required for medical acceptance.
This disparity has created a schism within the profession, characterized by philosophical differences between “straights” and “mixers.” “Straights” adhere closely to the original vitalistic principles, focusing on correcting the vertebral subluxation complex to promote overall wellness. Conversely, “mixers” integrate conventional diagnostic tools and focus on evidence-based treatment for biomechanical and musculoskeletal disorders, adopting a model more aligned with physical therapy.
Accusations of pseudoscience are often directed at practitioners who continue to treat the historical vertebral subluxation as the root cause of systemic disease. The mechanism of action for spinal manipulation is still not fully understood, but current scientific models relate it to neurophysiological and biomechanical effects on joints and muscles. Proponents of evidence-based medicine argue that when claims extend beyond joint mechanics to affecting immune function or treating internal organ diseases, the biological implausibility is too great without substantial proof.
Safety Concerns Related to Spinal Manipulation
A significant factor contributing to public and medical distrust is the rare but serious safety risk associated with high-velocity adjustments, particularly those performed on the neck (cervical spine). The primary concern is the potential for vertebral artery dissection (VAD), a tear in the inner lining of the vertebral artery, one of the main blood vessels supplying the brain. This dissection can lead to a clot formation, which may break off and cause an ischemic stroke.
While serious complications are extremely rare, their existence fuels medical skepticism and public fear. The risk is often debated: does the manipulation cause the dissection, or do patients already experiencing a dissection (with initial symptoms like neck pain and headache) seek out a chiropractor just before the stroke occurs? Several studies suggest the association may be coincidental, reflecting the natural history of the dissection rather than a causal link.
Nevertheless, tragic case reports involving young patients who suffer stroke or death following cervical manipulation underscore the inherent risk. Some medical professionals argue this risk outweighs the proven benefit for neck pain. The high-velocity thrust procedure can produce significant strain on the vertebral arteries, and anatomical differences mean that even experienced practitioners may not be able to guarantee safety. For many people, the specter of this low-probability, high-impact risk is enough to avoid chiropractic care entirely.
Scope of Practice Disputes and Inter-Professional Rivalry
The historical and philosophical separation of chiropractic from medicine naturally led to significant inter-professional rivalry and disputes over the scope of practice. For much of the 20th century, the American Medical Association (AMA) actively opposed the profession, attempting to “contain and eliminate” it. This opposition was later deemed an illegal conspiracy in the landmark Wilk v. AMA antitrust lawsuit, cementing a culture of distrust between the two professions.
Today, tensions persist regarding when a chiropractor should refer a patient to a medical doctor, especially for patients presenting with non-musculoskeletal symptoms. Regulatory boundaries vary widely by state, leading to inconsistent scopes of practice and creating confusion about the chiropractor’s role. Medical professionals often express concern when chiropractors step outside their area of proven expertise, such as managing infectious diseases or other non-spinal conditions.
Clear communication and mutual trust remain significant barriers to effective collaboration between chiropractors and other healthcare providers. Integrating chiropractors into interprofessional settings, such as hospitals or primary care clinics, has been shown to improve collaboration and knowledge sharing. However, philosophical clashes over the definition of health and disease continue to complicate referral pathways and professional working relationships.