There are a couple of different ways to do the chest fly exercise. One way is to use a flat bench and the other is to use an incline bench. The incline bench chest fly will put more stress on the upper part of your chest and anterior deltoids.
To perform the chest fly exercise on an incline bench you'll need an incline bench and a pair of dumbbells.
Performing the Exercise
Set the incline bench somewhere between 30 and 45 degrees. To get into the starting position grasp a dumbbell in each hand and lie flat against the bench with your feet flat on the floor. Extend your arms out above your chest with your palms facing each other and try to keep your arms slightly bent. You don't want them to be straight and stiff with your elbows locked. To perform the actual movement, slowly bring your arms down to about shoulder level and then return to the starting position. When you bring your arms together above your chest, be sure you only bring them close enough together to a point where your chest muscles are still being stressed. The dumbbells should never touch each other. Try to complete two to three sets of 8 to 12 repetitions.
When you perform this chest fly exercise on an incline bench you are using not only your chest muscles but the muscles in your shoulders and arms as well including your anterior deltoids, biceps and triceps.
The easiest way to prevent injury while doing any strength training exercise is to use a weight that is light enough for you to complete the movement with full control. If you lift too heavy you're likely to have poor posture and increase your chances of pulling or straining your muscles and tendons which could ultimately lead to a serious injury.