Sit down on a pull-down machine with a wide bar attachment on the pulley. Make sure that you adjust the kneepad as needed in order to ensure that the machine’s resistance will not raise your body. Grab the bar with your palms facing forward at a grip narrower than shoulder width. With both arms extended in front of you, bring your torso back at about a 30-degree angle and create a slight curvature in your lower back by sticking out your chest. Bring the bar down until it touches (or nearly touches) your upper chest by drawing the arms down and back. Once the bar has been lowered, focus on squeezing the back muscles briefly before slowly raising the bar back to the starting position. The upper torso should remain stationary throughout the course of the exercise so that only the arms are moving. Repeat the motion for the prescribed number of repetitions.