STARTING POSITION:
Select the appropriate weight of the dumbbell. Sit on a flat bench and grab the dumbbell to place it on your thigh. Lie back on the bench moving your arms to hold the dumbbell with a prone grip just above you with your elbow extended. Retract your shoulder blades rising your chest up.
MOVEMENT:
Slowly lower the dumbbell by bending your elbow until the dumbbell almost touches the chest while you inhale. Using your triceps muscle, push the dumbbell back to the starting position while you exhale. Repeat the movement for the specified amount of repetitions and then repeat with the other arm.
TIPS: Make sure you only move the forearm. Make sure your shoulder blades are always retracted.