Performing the: A Step-by-Step Tutorial Dumbbell Lying One Arm Pronated Triceps Extension
Slowly bend your elbow to lower the dumbbell in a semicircular motion towards the side of your head, keeping your upper arm stationary and your elbow pointed towards the ceiling.
Continue to lower the dumbbell until your forearm is about parallel with the floor, and you feel a stretch in your triceps.
Using your triceps muscle, lift the dumbbell back to the starting position, straightening your arm but not locking your elbow.
Repeat the movement for the desired amount of repetitions, then switch to the other arm.