Postural changes associated with pregnancy and their relationship with low-back pain.

This longitudinal study examined the postural changes that occur during pregnancy and their association with low-back pain. The lordotic curvature, kyphotic curvature and position of the line of gravity were measured. The degree of low-back pain was assessed using a daily pain diary. Each measurement was recorded in 30 healthy pregnant women on a monthly basis until term and once post partum. The results reveal many different postural behaviours, but the majority of women experienced a flattening of the lumbar spine during pregnancy. The changes in kyphotic curvature were not so well defined. In the majority of women the position of the line of gravity was unaffected during pregnancy. Most women experienced some degree of low-back pain but in most cases it was mild. Although Pearson product-moment correlations revealed few significant correlations, the most interesting finding was that in the early stages of pregnancy, the changes in lordosis and lowback pain were inversely related.