OK, if I understand your correctly, that is primarily a triceps exercise (an a old one at that). I guess your doing it as a triceps exercise, but it also hits the rear delts a bit. Seen this done standing or even face down on a bench/incline bench. Both short backwards movements.
If that works well for you, than great. But I might prefer the DB triceps kickback as hitting the triceps with a harder contraction. Can also do kickbacks while lying ( face up) on a bench. Starting from a bent arm full stretch position, just kickback the bar out and away from the head. Good Luck.