Also according to the ISU, jumps must have the following characteristics to earn the most points: they must have "very good height and very good length"; they must be executed effortlessly, including the rhythm demonstrated during jump combinations; and they must have good take-offs and landings. The following are not required, but also taken into consideration: there must be steps executed before the beginning of the jump, or it must have either a creative or unexpected entry; the jump must match the music; and the skater must have, from the jump's take-off to its landing, a "very good body position". Somersault-type jumps, like the back flip, are not allowed. The back flip has been banned by the ISU since 1976 because it was deemed too dangerous and lacked "aesthetic value".