This exercise works the posterior deltoids which visually widens your shoulder girdle. Your deltoids will also become more defined.
Stand with your feet slightly closer than shoulder width apart and take the dumbbells in hand.
With your knees slightly bent, arch your back a little and lean forwards.
Keep your elbows slightly bent.
As you exhale, raise your arms to the sides and pause at the top for 1-2 seconds. As you inhale, lower the dumbbells.
Keep your torso stationary (avoid swinging).
If it is difficult to maintain balance, you can rest your forehead against the side of an incline bench (having laid a towel out beforehand).
It is better to avoid this exercise if you suffer from migraines.
At the top, you can contract your shoulder blades further. Thus the middle and lower delts, rhomboids, teres major and infraspinatus muscle get worked.