Lie supine on your back and bend knees with feet on the floor. Your hands may be at your sides. Now extend your right leg up toward the sky, and one vertebrae at a time, slowly lift your back up off the floor, extending your hips and right leg as high as you can, contracting your abdominals AND your glutes. Pause at the top, and now come back down one vertebrae at a time. Continue on the SAME SIDE for the number of repetitions suggested. Now switch sides.
Keep your neck long, and always contract your abdominals, moving up and down one vertebrae at a time to protect your back.