Let's take a lesson this winter from penguins and Canadians: two species of rugged animal that have perfected the ice walk.  Have you ever seen a Canadian fall on a surface of ice while not playing hockey, or a penguin fall without the intention of sliding belly down on glacier? The thing about walking on ice is that you can't walk with your long-strided natural gait.  You have to switch up your movement to shorter shuffling steps that are very close to your center of gravity to prevent your legs from...