Stature loss and recovery in pregnant women with and without low back pain.

Abstract

To assess the loss of stature and its recovery in normal and pregnant women with and without low back pain (LBP) and to examine the relations between spinal shrinkage, recovery, and LBP. Stature changes were measured before and after physical activity in each group and differences in response compared between groups. A laboratory environment. Thirty-one women (7 pregnant without LBP, 8 pregnant with LBP, 16 nonpregnant with no history of low back disorders) were recruited using convenience sampling. Controls were recruited from the general community; subjects in the pregnant groups were recruited from local primary care groups. Not applicable. Stature change was assessed as the main outcome measure. Changes in stature were interpreted with respect to the woman's stature at the start of the trial. Stature loss induced by a moderate physical activity was similar (P>.05) in all groups (control, -3.99+/-1.13 mm; pregnant no back pain, -4.23+/-1.23 mm; pregnant with back pain, -4.57+/-1.53 mm). Differences were found after 20 minutes in a recovery position (P<.05): the controls were able to recover stature to a greater extent (111.2%+/-13.6%) than the other groups (P<.05). A negative correlation was found between regain in stature and LBP in pregnant subjects (r=-.81, P<.05). The pregnant women with LBP were unable to recover stature to the same extent as the controls and pregnant women without LBP. Results suggest that LBP in pregnancy may be related to the woman's diminished ability to recover, rather than the magnitude of the spinal shrinkage imposed during the task.