Back

Spines of Pregnant Women Are Slow to Recover

Low back pain (LBP) is common in pregnant women. In fact, up to 20 percent of women with LBP say that it started during pregnancy. No one is exactly sure why. Theories include the effects of hormones on the joints and ligaments and postural changes. But it is unclear physically what is happening to the spine in a pregnant woman with LBP.

These researchers took a step toward answering that question. It is known that lifting and carrying puts force on the spine. It is possible that this force causes the discs of the spine to lose fluid. Discs are fluid-filled cushions between the vertebrae. When they lose fluid, the spine actually shrinks a bit in length.

The authors measured spinal shrinkage in pregnant women with and without LBP. The control group was made up of women with healthy backs who were not pregnant. The spine length of all three groups was measured using special equipment. All the women then walked short distances with loads that gradually increased from nothing to about 13 pounds. Spine length was measured right after walking and again after 20 minutes of lying on the left side with the knees bent. The authors called this the "unloading" position.

All the women had about the same amount of spine shrinkage right after exercising. However, there were major differences in the groups' spine measurements after the unloading period. The control group actually recovered more than 100 percent of their original spine length. Neither pregnant group got back to their original spine length. But the pregnant women with no LBP recovered more spine length than the group with LBP.

All the groups recovered spine length during the unloading period. The authors think that this means that resting in the unloading position for longer periods and more often could help pregnant women with LBP.

References: Cintia L. Rodacki, MSc, et al. Stature Loss and Recovery in Pregnant Women With and Without Low Back Pain. In Archives of Physical Medicine and Rehabilitation. April 2003. Vol. 84. No. 4. Pp. 507-512.

Back