Single-group repeated measures for single rater reliability.To describe the intratester reliability for measurements of active lumbar spine mobility and pelvic inclination during standing obtained with the back range-of-motion (BROM) device.The BROM device has often been used to quantify lumbar spine active range of motion. No studies have reported the reliability of the BROM device in a clinical setting.One examiner measured all 3 planes of lumbar range of motion in 40 nonimpaired subjects. For each plane of motion, 2 BROM device measurements were made. Intraclass correlation coefficients were calculated to express the intratester reliability for each plane of motion measured.Intraclass correlation coefficients were in the range of 0.67 to 0.94 for lumbar measurements with the BROM device.Intratester reliability was fair to poor for sagittal plane measurements and pelvic inclination. Measurements obtained by the same examiner for lumbar lateral flexion and rotation with the BROM device, however, were reliable.