Video narration
Why don't your feet slide backward when you walk? Your shoes touch the floor, and the two surfaces resist sliding past each other. That helpful resistance is friction. Watch what happens as you take a step: your foot pushes backward on the floor. Friction pushes back on your foot, helping your body move forward. Friction is not just what slows you down; it is the grip that makes movement possible. That same grip lets bicycle brakes slow you down and helps you hold a glass. But friction is not always useful. Too much rubbing wastes energy, creates heat, and wears surfaces away. So friction can help motion-or hinder it-depending on the situation. On a slippery floor, there is less grip, so walking becomes difficult. Now you can answer the question: your feet do not slide backward because friction grips the floor, letting you push backward and move forward.