Comparison of Lumbopelvic Motions During Hip Medial Rotation Depending on Sex Differences and Chronic Lower Back Pain

Purpose: Hip rotation testing is important in the evaluation of chronic back pain. The purpose of this study was to investigate hip and lumbopelvic movement during hip medial rotation (HMR) in individuals with chronic lower back pain (CLBP). Methods: This study targeted 112 subjects in total: 28 healthy males and 28 healthy females, and 27 males with CLBP and 29 females with CLBP. Motion-capture device was used to measure the hip medial rotation angle (HMRA), lumbopelvic rotation angle (LPRA), and the rotation angle of the hip when lumbopelvic rotation starts during hip medial rotation. Results: When evaluating the healthy males and females using the hip medial rotation test (HMRT), healthy males showed a smaller HMRA than did healthy females (p<0.05). When evaluating the healthy males and the males with CLBP using the HMRT, males with CLBP showed a smaller HMRA and more lumbopelvic movements than did healthy males (p<0.05) in addition, their lumbopelvic movements occurred earlier during HMR (p<0.05). Finally, when evaluating the males and the females with CLBP using the HMRT, males with CLBP showed a smaller HMRA and more lumbopelvic movements (p<0.05), and their lumbopelvic movements occurred earlier during HMR (p<0.05). Conclusion: The HMRT is an important test for the evaluation of males, and especially males with CLBP, as they often experience an increased LPRA and decreased HMRA, with lumbopelvic movement occurring earlier during HMR when compared to other groups.