A true edge rising cut, that is being launched from prima custodia, while raising both hands high. It is done as a draw cut - with emphasis on the slicing action.
As such, the cut has quite a short reach, aspecially in comparison with its alternative, a false edge rising cut. This is not neccessarilly a flaw. You will use krucke siege only if you want to agressively close the distance; and krucke is well suited for that.
The name (krucke - crutch) was probably chosen because of resemblance of an old man trying to hit somebody with a crutch used as a walking support.