The shoulder press machine is a great way for beginners to start developing a strong, powerful set of shoulders. A broad set of shoulders are the pinnacle of toned muscular body and using a seated shoulder press machine will help to develop and condition the shoulder (deltoid) muscles in preparation for more advanced exercises. This Shoulder Exercise Targets your Trapeziums and Deltoid Muscles from a Weight Machine. Complete the exercise in a slow and controlled manner. Use a very light amount of weight until you are comfortable with the lift.Do not locks your elbows at the top of the lift.