When you walk, which type of friction primarily helps you push off the ground without slipping?

When you walk, the ground must hold your foot in place while you push against it, so the force that prevents slipping is static friction. Static friction is the grip that keeps your foot from sliding as you apply a backward push; it acts in the opposite direction to your attempted slip. This frictional force is strong enough to match the horizontal component of the push you generate. For example, when you step forward, your foot contacts the floor and static friction supplies the necessary forward pull so the foot stays planted until you lift it. Thus static friction is the key type of friction that lets you push off without slipping.