1. Sacro-iliac mobility can be demonstrated in vivo by measuring the movements of the ilia.
2. In the standing position, all motions of the trunk, with the exception of flexion and extension, normally are associated with unpaired, antagonistic movements of the ilia about a transverse axis that passes through the center of the symphysis pubis.
3. Rotation and lateral bending of the sacrum normally do not occur alone, but as correlated motions that are coincidental to antagonistic movements of the ilia.
4. The positions of the ilia in normal stance, as well as their relative mobility, are affected by the dominant eye and hand.
5. The average antagonistic mobility of the male ilia is found to be increased 33.0 per cent. above normal in those subjects who complain of sacrarthrogenetic telalgia.
6. Abnormal sacro-iliac mobility is a potent cause of the abnormal ligamentous tension that produces sacrarthrogenetic telalgia.
(C) 1936 All Rights Reserved.The Journal of Bone and Joint Surgery, Inc.