Fig. 1
From: A computer aided measurement method for unstable pelvic fractures based on standardized radiographs
The rotational direction of the right hemipelvis is indicated by the curved arrow symbol in each pelvis, and the coordinate systems are denoted by the capital letters of X, Y and Z. a and b represent the varus and valgus of hemipelvis around the Z-axis in the outlet plane, respectively. c and d represent the internal and external rotation of the hemipelvis around the Y-axis in the inlet plane, respectively. e and f represent the flexion and extension of the hemipelvis around the X-axis in the sagittal plane, respectively