a. A careful study of the anatomy and functions of the sacro-iliac joints precludes the possibility of subluxation or relaxation occurring except in severe crushing injuries or possibly during the later stages of pregnancy, when all pelvic ligaments are in a state of temporary relaxation.
b. The symptoms occurring in acute and chronic sacro-iliac lesions, as well as many of the sciaticas, are to be explained by sprains of the joint, the spasmodic action of the posterior musculature of the body and the sequelae resulting therefrom.
c. Manipulation for the cure of sacro-iliac lesions has, in the past, been practised by the average physician in a purely empirical way, realizing that it was of service in a certain number of cases. When performed with the definite idea of restoring the retracted muscles to a normal tension and the breaking down of periarticular adhesions, which may have formed as a sequence to the sprained joint, our efforts are guided by much more intelligence and foresight.
d. If sciatica is due to pressure upon the sacral plexus by direct impingement of the displaced joint surfaces, we would expect the pain and other sensory and motor disturbances to be more generally distributed to the pelvis and the entire lower extremity. Since sciatica is a rather late manifestation of the sacro-iliac lesion and is relieved immediately by stretching the retracted hamstring muscles, it would appear, in this instance at least, to be due to the irritation of the nerve as it passes between the bellies of the spasmodically retracted muscles.
e. On account of the frequent occurrence of anomalies of the spine and pelvis in this region, an x-ray examination can only be of positive value when checked up by a subsequent examination after a cure has been effected. The patient and the fluoroscopic tube must always be in the same relative position during each exposure in order to avoid deception. In differentiating other organic lesions, such as tuberculosis, syphilitic gumma, osteoarthritis, etc., the x-ray is of inestimable value.
f. Traumatic lesions of the lumbo-sacral articulation may simulate very closely, those of the sacro-iliac joint and may require a similar method of treatment for their relief.
g. The remarkable results achieved by bonesetters and osteopaths in the so-called "luxations" and "misplacements" of the lower spine or sacro-iliac joint, may be attributed to their manipulation of the joint and massage of the muscles, which may modify or relieve the symptoms after one or many treatments, depending upon how soon they give the patient the "proper twist."