Masaki M, Ikezoe T, Yanase K, et al. - Through a cross-sectional study of 19 asymptomatic middle-aged and elderly women [control (CTR) group], 16 middle-aged and elderly women with low back pain history (LBPH) (LBPH group), and 23 middle-aged and elderly women with LBP (LBP group), researchers examined the relationship of LBPH and LBP with sagittal spinal alignment, stiffness evaluated using ultrasonic shear wave elastography, and mass of the back muscle in community-dwelling middle-aged and old women. A notable and independent factor of LBPH was the stiffness of the lumbar multifidus muscle. In the LBPH group, the stiffness of the lumbar multifidus muscle was significantly higher in comparison with the CTR group. The lumbar lordosis angle in the standing position was an important and independent factor of LBP. The lumbar lordosis angle was significantly smaller in the LBP group vs CTR group. Therefore, in community-dwelling middle-aged and elderly women, LBPH was correlated with progressed stiffness of the lumbar multifidus muscle in the prone position and that LBP was related to the reduced lumbar lordosis in the standing position.