I can suck in my abdominal muscles to make myself look ‘super thin’. If I draw my abdominal muscles in far enough, there is a cavity that forms under my ribcage. It is just about the size and shape to fit a football in. So I can stick a football inside my ribcage
Every now and then I like to stand on my head and see how much water I can fit in there. When I puff my stomach back out, the water ‘explodes’ out, as if I ruptured something.
My dad can suck his stomach in so far you can see the bulge where the front of his vertibrae are. :eek: