 The pull on the knot at the end of the drop levers the jaw and head violently up and to the right, which combines with the jerk of the rope becoming taut to wrench the upper neck vertebrae apart.This produces very rapid death, whereas the traditional position beneath the ear was intended to result in the mass of the knot crushing closed (occluding) neck arteries, causing cessation of brain circulation.The knot is non-jamming but tends to resist attempts to loosen it.