The holey spine: a summary of the history of scientific investigation of the intervertebral foramina.

The intervertebral foramina (IVFs) are important to all individuals who treat disorders of the spine, but this region is of special historic significance to chiropractors. This is because some of the earliest descriptions of the mechanism of action of chiropratic were related to the IVFs. The history of investigation of the IVFs is very rich spanning time from the fifth century B.C. to the present. Several professions were based upon theories related to the IVFs or upon serious investigations of the IVFs, and the results of other investigations were reported out of proper context in order to criticize chiropractic and other professions. The history of investigation of the IVFs can be divided into three time periods: 1) very early descriptions of neural foramina and the IVFs; )2 discussions of IVFs by developing professions and the studies of the IVFs by Swanberg in the early twentieth century; and 3) studies of the IVFs in the middle and late twentieth century. This paper discusses the major activities of each of these time periods.