A shrug is a shrug. Front or back doesnt matter, unless its the additional stress your putting on the shoulder that make you like them. I personally dont do shrugs or anything of the nature to specifically train the traps. Like most hae said, deads either from the floor or racked, olympiclifts, especially high pulls or shrugs with the use of a hex bar. The hex bar keep the hands in a neutral position and keeps some of the strain off of the shoulders.
Have to disagree on that point. My traps are very wide and thick. they lay back on myshoulders like two slabs of meat, but they have no height. The only way I have found to get height is by shrugging behind the back with strict form. Just like any other muscle, you can isolate different regions of the traps. That has been my experience anyways.
im going to tell you how to get some peak on those traps bro..site injections.i had the same problem..u can deadlift for years.you can do shrugs for years.u can do up right rows for years...u can anything and everything....they wont get to the point of peak.......but if u start hitting them with oil they will get bigger....i promise u that.......dw