To identify the pattern of pain, postural alignment of the frontal plane, and muscle stiffness of the lumbar area during pregnancy and postpartum. Methods: Twenty six primipara and 11 non-pregnant women were recruited as a pregnant group (PG) and control group (CG), respectively. The location and intensity of pain, postural alignment in the frontal place, and stiffness of the erector spinae at levels of L1 and L3 were obtained at the 34th, 36th week of pregnancy and 1 week, 1 month postpartum (34W, 36W, 1W, 1M, respectively). The data were compared between PG and CG. Results and Discussion: 1) Pain around the lower back showed no significant increase, but there was complaint of increased low back pain in late pregnancy, 2) Pain around the sacroiliac joint and width of the pelvis significantly increased at 36W and decreased at one month after delivery, 4) Stiffness of lumbar muscles increased asymmetrically in late pregnancy and continued until one month after delivery. Conclusion: Educational intervention that supports activities after delivery may be necessary to avoid complications after delivery.