breebop.com

As bad as backache can be during pregnancy, it would be a whole lot worse had women’s spines not evolved to flex and support the characteristic belly-out, back-bent preggo stance. As big-bellied women adjust their stance to accommodate a new centre of gravity, the lower vertebrae shift to prevent damage to the spine.

“What women do when their pregnancy reaches about half of the expected mass … they shift backwards,” Shapiro said.

“If you didn’t have any of those mechanisms, the only way to offset a load in front of you is to contract your back muscles. The more you have to use your muscles, the more discomfort you would have. It would be worse otherwise, and there would be more potential damage to the vertebrae.”

Men don’t have the same adaptation, though.

“We can only conclude that men can’t resist the forces of their big bellies as well as women. They are at a disadvantage,” she said.

“They probably lean back the same way to try and balance that load, but they are kind of putting their vertebrae more at risk. I am sure there has got to be a correlation between having a big beer gut and having back pain.”

- Pregnant? Backache? Thank evolution | Oddly Enough | Reuters.com

Well, there ya go.