Sex differences in pelvic and hip flexibility in men and women matched for sit-and-reach score

The purpose of this study was to test sex differences in sagittal plane thoracic (T), lumbar (L), and pelvic (P) angles measured during the sit-and-reach (SR) test and hip joint angle during a passive straight leg raise (SLR) test in men and women matched for SR scores. Thirty-five men and 35 women performed a standard SR and SLR test. Among the 70 subjects, 25 male and female pairs were identified using <5% difference in the SR score as the pairing criterion. Both SR and SLR tests were videotaped and subsequently analyzed using a computer software angle tool to measure T, L, and P angles during the SR test and hip joint angle during the SLR test. In paired men (M) and women (W), P angle (M: 96.6 ± 9.4° vs. W: 104.7 ± 12.4°) and hip joint angle (M: 87.1 ± 10.5° vs. W: 100.4 ± 12.1°) were lower and L angle (M: 26.3 ± 10.8° vs. W: 21.1 ± 7.6°) was greater in men. There was no difference in the T angle (53.3 ± 11.6° vs. 51.2 ± 11.4°) between men and women. Correlation coefficient indicated that the SR score was moderately associated with the P angle in both men (r = 0.82) and women (r = 0.83), whereas the traditional criterion measure for hip flexibility, SLR hip joint angle, demonstrated a relatively low correlation to SR scores in both men (r = 0.60) and women (r = 0.56). These data indicate that the SR score does not distinguish spine and pelvic flexibility differences in men and women and does not adequately assess hip flexibility.