I saw Nirvana on an old SNL rerun. The bass player had his axe hanging way down near his knees. Both of his arms were nearly straight. His right hand was using a pick and his left wrist was so far straight that his thumb was way up over the fretboard. He sounded OK to me, but that type of position sure looks like a hard way to go. I suppose that guy must be used to it. I wonder if he is fretting notes with his thumb too.