The fourth, fifth, and sixth waves of chiropractic ideas encompassed a sixty-two year period. It was a very complex time for the chiropractic profession. The period was characterized by the basic science laws to the political infighting, the upgrade in education, explosion of techniques and instrumentation, and the diversity of subluxation theories. The fourth wave started in 1928, the year of Tom Morris‘ death, and ended in 1948, the year of Mabel Palmer’s death. This wave included the publication of the Canadian Memorial Chiropractic College technique manual, a new edition of Jim Firth’s book, as well as the initial and active phase of the B.J. Palmer Research Clinic. The fifth wave started in 1949 with the publication of books by T.F. Ratledge, Jim Drain, and B.J. Palmer. During this time, B.J. Palmer published fourteen more books. The fifth wave ended in 1961, the year B.J. died. The sixth wave went from 1962 to 1975 and included the publication of two of B.J. Palmer’s final books, William Harper’s Anything Can Cause Anything, and Segmental Neuropathy. The sixth wave ended with the landmark NINDS conference.