Changes in upper and lower lumbar lordosis according to posture in two age groups. Lordosis was measured in upper and lower regions of the spine, defined according to anatomical characteristics. Kyphotic and lordotic changes in upper lumbar lordosis varied according to postural changes in younger subjects. However, nonsignificant changes were observed in older subjects. No changes in lower lumbar lordosis were observed during change from a standing to supine position in either age group. In contrast, a drastic change was identified in sitting positions in the young group compared to the older group.