CLINICAL SIGNIFICANCE OF THE TRANSITIONAL LUMBOSACRAL VERTEBRA

It has been accepted that man's penalty for assuming an upright position is low back pain; however, it is equally evident that evolutionary processes are attempting to strengthen the unstable lumbosacral joint. In 1876, Rosenberg theorized that the vertebral column was undergoing a shortening process in an effort to stabilize the erect spine. He felt that sacralization of the fifth lumbar vertebra was anthropologically progressive, whereas lumbarization of the first sacral vertebra was regressive. Others have felt that transitional variations at the lumbosacral joint are due to strains created by a mobile fifth lumbar vertebra resting on an immobile first sacral vertebra. It is felt that the three most important steps in the evolution of the treatment of the spine for back pain are: (1) discovery of roentgen rays in in 1895, (2) discovery of spinal fusion in 1911, and (3) the demonstration of the role played by the inter-vertebral