Apply a resistance band around your legs and move it to above your knees. Lie on your side with head comfortably supported and knees bent. Knees and hips should be stacked perfectly on top of each other, and feet should be in a straight line with your tailbone and head. Then push your top knee upwards to the ceiling. Make sure your hips stay stacked; it is easy to roll your body backwards instead of pushing your knee straight up. You can hold in the open position for 30-60 seconds or open and close for a quantity of reps.