This exercise involves trying to keep hamstrings turned off, enabling the glutes to do the primary work.
Lie supine on the floor, with the toes against the wall. Actively slide the toes into the wall, using the quads to isometrically extend the knees. The idea is to inhibit the hamstrings. While maintaining a neutral spine and level hips, extend the hips up toward the ceiling. Slowly and with control, lower back down to the starting position.