Hello and thank you for visiting AikiWeb, the
world's most active online Aikido community! This site is home to
over 22,000 aikido practitioners from around the world and covers a
wide range of aikido topics including techniques, philosophy, history,
humor, beginner issues, the marketplace, and more.
If you wish to join in the discussions or use the other advanced
features available, you will need to register first. Registration is
absolutely free and takes only a few minutes to complete so sign up today!
...a 2007 study on the evolutionary reasons pregnant women don't tip over.
Scientists(as well as far more casual observers of the human condition) have long noticed that pregnant women lean back to avoid toppling over. But that can put extra pressure on their spines, leading anthropologists to theorize that women's lower vertebrae evolved to reduce such pressure during pregnancy.
Shapiro and her fellow researchers found out just how. By studying 19 pregnant women, they discovered that a woman's lumbar, or lower back, curve extends across three vertebrae. In men, it extends across two. The joints between the vertebrae also are larger in females and angled differently from those of males to better support the extra weight.