STARTING POSITION:
Select the appropriate resistance on the weight stack. There should be a handle that is attached to a low pulley. Grab it with your right hand and stand up straight with your left shoulder pointing to the pulley. Contract your pelvic floor and core while keeping your chest up.
MOVEMENT:
Lift the handle to your side until your arm is parallel to the floor while you exhale. Return to the starting position in a smooth movement while you inhale. Repeat the movement for the specified amount of repetitions and then repeat with the other arm.
TIPS: The exercise key is quality over quantity. The trick is to perform the exercise using proper form. While your are doing the exercise, move only the shoulder joint, make sure you don't move any other part of your body.