Upper to Lower Segment Ratio

The Upper to Lower Segment Ratio is defined as the length from the top of the symphysis pubis to the top of the head, divided by the length from the top of the symphysis pubis to the sole of the foot. The segments are most easily calculated by measuring from the symphysis pubis to the floor to measure the lower segment. Next, the lower segment is subtracted from the total height or total length to give the upper segment. Finally, the length of the upper segment is divided by the length of the lower segment.

From Styne, MD, Pediatric Endocrinology, Upper-to-Lower Segment Ratio, Lippincott, Williams and Wilkins, copyright 2004, pg 57, fig 5-7. Adapted from from Engelback, LW. The diagnosis and treatment of endocrine disorders in childhood and adolescence. Springfield, IL: Charles C Thomas Publishers, 1965.