Ever notice how your "Eureka" moments usually happen when you're on the go and out of the office? It's hard to find flow in a cubicle. And there's a good reason for that. You're sitting in a box. Next time you're feeling stuck and your mind seems as blank as your screen, remember this: studies show body movement can unlock creative ways of thinking-no matter what kind of problem you're trying to solve. Here's how to use physical activity to get out of a rut and get your imagination in motion.