Inter- and intrarater reliability of a back range of motion instrument

Objective: To examine the interrater and intrarater reliability of a back range of motion (BROM) instrument when measuring lumbar spine active planar motions and pelvic inclination. Design: Single-group repeated measures for inter- and intrarater reliability. Setting: Academic institution. Participants: Ninety-one participants (61 women, 30 men; mean age, 28y) without a current complaint of low back pain volunteered. Intervention: Two examiners measured pelvic inclination and all lumbar motions by using the BROM device. Subjects alternated between examiners for 4 complete trials; examiners remained blinded to the measurements. Main Outcome Measures: Intraclass correlation coefficients (ICCs) were used to determine intrarater and interrater reliability. Regression analysis was performed to determine the role palpation played in sagittal plane measurement error. Results: Intrarater reliability for side bending was good (ICC range, .85-.83), lumbar forward flexion and pelvic inclination was good to fair (ICC range, .84-.79), and extension and rotation was fair to poor (ICC range, .76-58). Interrater reliability was fair to poor for all lumbar motions and for pelvic inclination (ICC range, .79-.55). Less than 2% of the variation in sagittal plane measurements was explained by consistency of palpation for device placement. Conclusions: The BROM provides a reliable means of measuring lumbar forward flexion, side bending, and pelvic inclination when performed by the same examiner in asymptomatic subjects.