Joshua Slocum said:Consider the difference in strength between a row of stone blocks, and an arch. When you're in a hollow, your spine is like the arch.
A neutral spine is optimal if you are supporting a load along the axis of your spine. For example, if you're balancing a heavy weight on your head, you want to try to make your spine as straight as possible (also called "stacked"). However, as Coach mentioned, when your body is horizontal, placing a slight curve in the spine allows it to support itself better.
Ok now I'm confused. I thought a neutral spine IS in an arch, or several - the famous s shape you can see in any model of the spine. I thought the hollow body position used in a handstand simply eliminates the lumbar spine arch. Or is this not considered hollowbody? I'm a long way off attempting levers etc, but I'm curious: is the 'hollow' position the same for f-lever, planche, flag etc or do they vary in degree?
Also, curious, when performing vertical elements, would a gymnast use a hollow body? I don't know what they are called in gymnastics, but in ballet its called a double tour - when you jump upwards vertically and spin around twice whilst staying vertical. Or are these jumps performed with a neutral spine?