A horizontal line between the highest point of the iliac crest on each side crosses through the spinous process of vertebra LIV. The LIII and LV vertebral spinous processes can be palpated above and below the LIV spinous process, respectively (Fig. 2.67A).
The sacral dimples that mark the position of the posterior superior iliac spine are level with the SII vertebral spinous process (Fig. 2.67A).