Figure 4 From: Three dimensional evaluation of posture in standing with the PosturePrint: an intra- and inter-examiner reliability study Postural rotations. Using a right-handed Cartesian coordinate system with X-axis positive to the left, Y-axis positive vertically, and Z-axis positive to the anterior, postures of the head, rib cage, and pelvis can be described as rotations (Rx, Ry, Rz) around these axes.Back to article page