The lateral waist bump increases the difficulty of the lateral hip bump. This exercise is performed to challenge the hip stabilizers and increase strength and endurance of the hip. Placing foam under the foot increases the difficulty by making it unstable. At first, place the foam 6 inches from the wall. When you become more comfortable with the exercise, move the foam further from the wall. Perform the exercise with slow and controlled movements.
This exercise can become more difficult with incorporating weights or squatting. Closing the eyes and using more unstable foam will also make it harder.