More patients present themselves in the orthopedic department of the Stanford Clinics with backache than with any other complaint. It is frequent in private practice, and is a source of controversy in industrial accident work. Various pathologic entities have been advanced to account for it, some of them purely theoretical and, I believe, erroneous. To treat the symptom scientifically and indeed successfully one must be able to demonstrate definite facts which will account logically for the symptoms and clinical signs. Among the diagnoses which I have discarded as not satisfying these requirements are renal disease, prostatic hypertrophy, neuritis, muscular strain, faulty posture, myositis, fibrositis, fasciitis, radiculitis, rheumatism and pressure on the spinal nerves.
In order to clarify what follows I shall devote a few words to the anatomy of the bones and joints of this region. The bones are the three lower lumbar vertebrae, the sacrum and the two innominate