I am sorry but I have no idea what this even means.. I am guessing, intepreting that maybe it means is the butt of the boss burdened? As in, is it difficult being the boss?
Sometimes, yes, sometimes no.. I had a boss once, a chef, who did NOTHING, his only task was to make everyone else do all his work and to shout and bully them.. I don't imagine he had a lot of burden on his butt.