 Then Google what protects the nervous system. Well, obviously your brain's protected by your skull, but what about the extension of your brain? Well, it just so happens that God gave you a spine. Why is your spine made out of bone? Because it's protecting the most important system in your body, your nervous system. So listen, if your nervous system went through your knee, I'd be a knee specialist. If it went through your hand, I'd be a wrist specialist.