HOW: Begin on your side with your shoulders, hips, knees, and ankles stacked over each other. In this side lying position open your top knee up towards the ceiling. Your feet can stay in the same position, make sure this motion is driven from the knee.
FEEL: You should feel the outer hip, particularly the glute muscles with this exercise.
COMPENSATION: Avoid rotating your entire trunk with this exercise, make sure your chest does not open up towards the ceiling.