Fluctuating asymmetry and low back pain

Fluctuating asymmetry (FA), a pattern of bilateral variation that is normally distributed around a mean of zero, appears to correlate inversely with fitness and health. In this study, we compared the FA of asymptomatic control subjects (n = 51) and patients with low back pain (n = 44). We measured eight traits, from the upper and lower limbs, and used them to obtain asymmetry indices for each subject. We also measured pelvic asymmetry in standing subjects. The low back pain (LBP) group showed significantly higher asymmetry in the pelvis, and in ulnar length and bistyloid breadth. Our results demonstrate a link between LBP and asymmetry not only in a weight-bearing trait (i.e., pelvic configuration), but in two traits that are not functionally related to the back (i.e., ulnar length and bistyloid breadth). We can now consider LBP as another health and fitness measure correlated with FA. (C) 2004 Elsevier Inc. All rights reserved.