Performing the: A Step-by-Step Tutorial Dumbbell One Arm Reverse Fly
Lean forward slightly from your waist and bend your right knee slightly, keeping your back straight.
Extend your right arm straight down from your shoulder, then raise the dumbbell out to the side and up until it's at shoulder level, keeping your arm slightly bent at the elbow.
Slowly lower the dumbbell back to the starting position in a controlled manner.
Repeat the exercise for the desired number of repetitions, then switch to your left hand and repeat the process.