When you stand up and walk friction is an essential aid. There is friction between your foot or shoe and the ground. Sometimes the friction is high, like walking on carpet, and sometimes it is low when stepping on shiny tiles. Stand up and take a couple of paces, noticing what happens. You will observe that as you raise one foot and move it forward the rear foot grips the floor. By this method you are able to push against the floor surface and move forward confidently.
