Reverse Machine Flyes are an effective exercise for targeting the rear deltoid muscles and the upper back, including the rhomboids and trapezius. To perform this exercise, sit facing the reverse fly machine with your chest against the pad and your feet flat on the floor. Grasp the handles with an overhand grip, keeping your arms slightly bent. Keeping your back straight and chest pressed against the pad, pull the handles outward and backward in a wide arc until your arms are extended to the sides. Squeeze your shoulder blades together at the peak of the movement, then slowly return the handles to the starting position. Reverse Machine Flyes help improve shoulder strength, enhance upper back muscle definition, and promote better posture. Adjusting the weight on the machine allows you to vary the intensity of the exercise to suit your fitness level.