Cable one arm incline fly on exercise ball

Sit on an exercise ball with your feet flat on the ground and your back against an incline bench. Hold a cable handle in one hand with your arm extended and palm facing inward. Keeping a slight bend in your elbow, slowly lower your arm out to the side until your hand is in line with your shoulder. Pause for a moment, then squeeze your chest muscles to bring your arm back to the starting position. Repeat for the desired number of repetitions, then switch arms.