Fig. 10

A An AP pelvic radiograph of a patient with a level pelvis is shown. Notice the relative bilateral symmetry in the size and shape of the obturator foramina, the iliac wings, the ischial spines, and the ischial tuberosities. This symmetry, viewed in context of the relative vertical alignment of coccyx and the midline of the pubic symphysis gives us an overall impression of a lack of PO. B A PO of 5° is seen in this radiograph. Notice the bilaterally asymmetric heights of the iliac crests and the relatively increased vertical malignment of the tip of the coccyx and the midline of the pubis compared to the neutral pelvis. C At a PO of 10°, the asymmetry between the bilateral obturator foramina and the heights of the iliac crest become much more profound. D Demonstrating even greater postural asymmetry, this radiograph shows a PO of 15°