Chiropractic: history and overview of theories and methods - PubMed (nih.gov)
Chiropractic was started by D. D. Palmer, a magnetic healer who formulated the vertebral subluxation theory. The profession was developed by his son, B. J. Palmer. Although the definition of chiropractic as a method of correcting vertebral subluxations to restore and maintain health is questionable, spinal manipulation is of value in the treatment of some types of back pain. The chiropractic profession is still based on the vertebral subluxation theory, and has the confusing image of a back specialty capable of treating a broad scope of health problems.
The woo was baked in at the founding of the scam. I am actually shocked to learn that it has been separated to some degree from it in Japan.