While standing upright, hold a barbell plate in both hands at the 3 and 9 o'clock positions. Your palms should be facing each other and your arms should be extended straight out in front of you. This will be your starting position.
Initiate the movement by rotating the plate as far to one side as possible. Use the same type of movement you would use to turn a steering wheel to one side.
Reverse the motion, turning it all the way to the opposite side.