uhh, i don't think that would really fit in to the game, i mean, where are u gonna find a shield in 2281. shields stopped being used long before the war in 2077, and any shields in museums were likely destroyed in the war.
Not antique sword and board shields made of wood and iron... modern riot shields. Look in any daily CNN news feed, and you'll see thousands of them in use. Everywhere. All over the world.
But, that little factoid aside, shields have traditionally been most useful in group combat situations, where you have lines of men with sheilds working close together and protecting each others flanks. As a solo combat item, it would just slow you down and make you easier to kill in any situation with more than one opponent. And if they have guns, it would just be laughable.