Elbows are usually pretty easy to dismember, as long as you hit from the right direction. If you hit it "with" the axis, it's pretty much impossible to dismember without a RAGEPOWAR attack, but if you hit it on top, below or behind, it will snap pretty easily. A relaxed elbow is, of course, harder to bork than a held elbow, but the same things apply: don't hit with the axis, hit against it.