Investigation of the flexible ruler as a noninvasive measure of lumbar lordosis in black and white adult female sample populations.

The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or reflecting the views of the Army, the Department of Defense, or the U.S. Government. The purpose of this study was to investigate the validity of the flexible ruler as a noninvasive measure of lumbar lordosis in black and white adult females. The bony landmarks of the second lumbar vertebra (L2) and the intersection of the posterior superior iliac spines (PSIS) were palpated and marked on 45 adult females (21 blacks, 24 whites). Potential subjects with a previous history of activity-limiting low-back pain, spinal surgery, or spinal anomaly were excluded from the study. A lateral lumbosacral roentgenograph was taken of each subject, and an actual (skeletal) lumbosacral lordosis angle (ALS) was calculated from the roentgenograph. A flexible ruler was then molded to the contour of the subject's lumbosacral spine, and the previously marked L2 and PSIS intersection bony landmarks were located on the flexible ruler. The flexible ruler lordosis angle (FRA) was then calculated and correlated to the subject's ALS. The criterion validity of the flexible ruler as a measure of actual lumbosacral lordosis was poor (Pearsons' Correlation Coefficient = 0.30, N = 45). Because of the poor criterion validity of the flexible ruler compared to roentgenographically confirmed lumbar lordosis, the flexible ruler has questionable clinical value in the assessment of lumbar lordosis. J Orthop Sports Phys Ther 1989;11(1):3-7.