Position yourself in a back extension station and hook your feet under the leg anchor. Your body should form a straight line from your hands to your hips. Lower your torso, allowing your lower back to round, until it’s just short of perpendicular to the floor. Raise your upper body until it’s slightly above parallel to the floor. At this point, you should have a slight arch in your back, and your shoulder blades should be pulled together.
Pause for a second, then repeat.