How?

Starting with the rope behind you, pull it up and over your head. As the rope passed directly over your head, begin to crouch down toward the floor by bending your knees slightly and leaning forward. Bring your chest low enough so that is it parallel with the floor and then place the rope on the floor in front of you bringing it to a complete stop. Usually, this will be the entry point for another skill, but in the absence of any other skill, exit this position by gently pulling the rope toward your feet and letting your hands pass your ankles. Then begin to stand back up and jump the loop of the rope as it reaches your toes. Then bring the rope over your head and jump the rope in an Open.

Why?

The ground stall is a foundational movement which is the entry point for a lot of other skills such as the Caboose or the Push-Up.