Performing the: A Step-by-Step Tutorial Dumbbell One Arm Reverse Fly
Extend the arm with the dumbbell straight down from your shoulder, keeping a slight bend in your elbow, this is your starting position.
Keeping your torso still and your arm slightly bent, lift the dumbbell up and out to the side until it is at shoulder level.
Pause for a moment at the top of the movement and squeeze your shoulder blades together.
Lower the dumbbell back to the starting position in a controlled manner to complete one repetition. Repeat the exercise for your desired number of reps before switching to the other arm.