Set up for the exercise by setting an adjustable back bench to an angle of around 30-40 degrees.
Grab a set of dumbbells and position yourself with your chest on the bench.
Your feet should be used for stability on the floor, your shoulders should be about level with the top of the back padding and you arms should be hanging - holding the dumbbells with a neutral grip (palms facing one another).
Moving only at the shoulders, raise your arms in a semi-circular motion out to your sides until your arms are parallel to the floor. Keep a slight bend in your elbows throughout the movement.
Squeeze your shoulder blades together at the height of the movement and then begin slowly lowering the dumbbells back to the starting position.