is this a workout that pitchers should do? what does shrugs work and how is it beneficial?

As part of an overall strength and conditioning plan, yes, it’s fine. Use dumbbells at your side. Straight up, straight down; don’t roll your shoulders.

Why not?

I stoped doing just shrugs…Deadlifting more than just takes care of any trap work. I suggest getting into cleans [quote]12 Steps to the Perfect Clean

but if you have to shrug look up a kettlebell (dumbells could be used for this) JUMP SHRUG