It is one of the few exercises for the posterior deltoid that you can do in isolation, apart from the work you receive in shoulder extension movements, such as paddles and dorsal pulls.
Stand, holding dumbbells with a neutral grip. Lean forward until your torso is parallel to the ground, keeping your knees bent and your arms stretched. Raise the weights vigorously until your hands are close to shoulder height. Fully contract the posterior deltoid, bringing the scapula closer together. Get down to the starting point without dropping the weight. Throughout the exercise, you must keep your elbows almost stretched so that the back shoulder works more.