The Relationship between Pelvic Tilt Angle and Disability Associated with Low Back Pain

Abstract

[Purpose] The main purpose of this study was to examine the relationship between pelvic tilt angle and disability associated with low back pain in adults. [Subjects] The subjects were 119 adults (56 males and 63 females) ranging in age from 18 to 55 years. Subjects with marked posterior pelvic tilt (PPT group) and marked anterior pelvic tilt (ATP group) were identified. The PPT group consisted of 6 males and 6 females with pelvic tilts of at least one standard deviation below the mean of healthy back subjects. There were 22 males 30 females in the APT group with pelvic tilt greater than one standard deviation above the mean. [Methods] Subjects completed a questionnaire about dominant working position and demographic variables. Pelvic tilt angle was measured using a modified inclinometer. [Results] Median disability scores of both males (9.1%) and females (10.9%) showed subjects were minimally disabled. Spearman correlation coefficients for the between pelvic tilt angle and the Oswestry disability index of male and female subjects in the PTT group, the APT group, and of all subjects were not significant. However, in the post hoc analysis a small but significant difference in pelvic tilt angle (p<0.001) between the normal and disability groups was discovered. Subjects with low back pain showed a significantly greater median pelvic tilt angle (6.0°) than those with healthy backs (3.5°). [Discussion and Conclusion] The results might indicate that low back pain suffers change their posture by increasing anterior pelvic tilt or it could mean that those with increasing pelvic tilt are more at risk of having back pain. Further study is recommended to investigate this relationship in subjects with moderate to severe disability.