The influence of pregnancy on the location of the center of gravity, postural stability, and body alignment

Abstract

• 1. The anteriorly unbalancing load of pregnancy causes a temporary overcompensation which displaces, backward, the average location of the vertical projection of the center of gravity in the sagittal plane.

• 2. Pregnancy appears to be associated with no alteration in the subject's normal sinistral asymmetry of stance.

• 3. The multijointed segmented body counterbalances the disequilibrating effects of pregnancy by elevation of the head, hyperextension of the cervical spine and extension of the knee and ankle joints. Relatively slight visible adjustments occur in the lumbar spine.

• 4. There is an apparent significant decrease in postural stability which persists throughout the puerperium.

• 5. Since the alignment at the end of puerperium is an almost exact duplication of that assumed in the early months of pregnancy, the gravida has successfully resisted the chronic disrupting force without any significantly permanent change in the postural mechanism.