I have always wondered the reason why we swing our arms when we walk. There is no human being on planet earth who walks with their arms pinned by their sides. Everyone walks with both arms going up and down like a pair of well trained army boots . I once tried to walk with my arms pinned to my side and I looked like a mechanical robot. It wasn't nice at all. It wasn't that uncomfortable, but it was really weird. So why do you think we swing our arms when we walk?