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Post by jmo on Dec 13, 2007 9:59:37 GMT -5
Pregnant women do not tip over, and researchers say an evolutionary curve has a lot to do with the reason why. Anthropologists studying the human spine have found that women's lower vertebrae evolved in ways that reduce back pressure during pregnancy, when the mass of the abdomen grows by nearly one-third and the center of mass shifts forward considerably. That increases pressure on the spinal column, strains the muscles and generally reduces stability. Even without the benefit of advanced study in biomechanics, women tend to deal with the shift — and avoid tumbling over like a bowling pin — by leaning back. But the solution to one problem creates another because it puts even more pressure on the spine and muscles. more
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