Put a dumbbell on the floor beside a flat bench. Lay across the flat bench with only your shoulders touching the bench so that the dumbbell is above your head.
Starting position – Reach back over your head and grasp the dumbbell under the top plate and lift the weight up over your chest with your palms facing up and arms straight.
Movement – Lower the weight over your head toward the ground without bending your arms, as far as you can making sure to stretch out completely. Then bring it back up over your chest again.