The chest must rotate around the spine without changing the spine angle. Imagine standing inside a tube, turning the upper ...

Modern Hula-Hoops are plastic rings you twirl around your body by moving your hips. This swiveling motion is similar to that ...

The gyrations of hoop-slinging robots reveal that hourglass-shaped objects are best at keeping a hoop in the air.

Or sign-in if you have an account. It turns out that hula hooping comes naturally to certain people and no matter how hard others may try, they still won’t be able to keep the hoop elevated for ...