Historical overview and update on subluxation theories☆

OBJECTIVE This article presents a personal view of the historical evolution of theories of subluxation in the chiropractic profession. DISCUSSION TWO MAJOR THEMES EMERGE FROM THIS REVIEW: those related to the mechanical behavior of the spine and those related to the neurologic implications of these mechanical issues. Chiropractic subluxation theory is one of the few health-related theories whereby these mechanical and neurologic theories have been unified into a comprehensive theory of disorder of spinal function. For this disorder, doctors of chiropractic have used the term subluxation. These theories, and their unification in the "subluxation concept," have undergone evolution in the profession's history. CONCLUSION The "subluxation concept" currently faces challenges, which are briefly reviewed in this article. The only way forward is to strengthen our efforts to investigate the "subluxation concept" with high-quality scientific studies including animal models and human clinical studies.