Footlocks are a group of wraps on your foot that lockout your position on the fabric. Generally, a single footlock uses both fabrics on one foot. A double footlock puts one fabric on each foot. An open footlock has one fabric on your foot and the other is free, "the free pole/side/fabric/tail." This video goes into depth about figure 8 footlocks from the ground into the air, including dancer footlock from ground to air, ankle hang, and single ankle hang. Not only are footlocks designed for upright wrap scenarios, there is just as much important material to be covered in them from the upside down!
One of my goals is to provide information and inspire viewers in making setups beautiful. To take even the smallest piece of information and get dorky about it. It doesn't have to be "Ignore this part while I set up!..." Challenge yourself to taking all the steps to refine your movement.