Abstract
The role of the psoas major that had not been described in terms of lumbar postural changes was studied by analyzing its shape, size and position in 41 young adult women and 48 women of middle and advanced age. The women of middle and advanced age had significantly decreased lordosis in L1-L5, L3-L5 and L1-S1 and decreased sacral inclination. On CT scans at the middle of the L5 body, the psoas major is shaped round in the young adult women and shaped like a teardrop in the women of middle and advanced age.The center of the psoas major had shifted anterioly by 7mm in the latter. Those results indicate that the psoas major plays as a flexor rather than a stabilizer of the lumbar spine in the advanced age.
