Everywhere that I've read about handstands, and I do mean everywhere, people say to extend the shoulders so that you're touching your ears.
What I've never understood is why? Wouldn't having the shoulder back against the rib cage be a stronger and more stable position? I can understand training with extension for the strength aspect, as that movement is very important in gymnastics, but why is shoulder extension so important for handbalancers? What does it accomplish?