Contintually pecking at an arm in a non sporting situation is pretty stupid.
That said, slamming a strike down on a shoulder or arm on the way it is often a good idea. It clears the arm so that you can continue in unguarded as well as gets them to immediately experience pain while you continue to attack. It quickly puts them on the defensive. But agian, I woul only suggest it as a "hard check" during an attack.
JWT
If you pr!ck us, do we not bleed? If you poison us, do we not die? And if you wrong us, shall we not revenge? If we are like you in the rest, we will resemble you in that the villany you teach me, I will execute, and it shall go hard but I will better the instruction. MOV