the shoulder support is really where they made the huge stride in the seat belt. The lap belt really didn't do much other than helping maintain the position of the person in the seat during a roll over or a slide. Your body would still fold over just as easily and there is really nothing you can do about becoming one huge hinge when you hit a poll at 60 mph. With the tilt locking mechanism in the belt console and the shoulder strap, if everything works as it should, you aren't going anywhere. Thats why 25 years ago there wasn't a damned case of whiplash, everyone just has broken necks/noses/jaws. Now, the only thing NOT locked against the seat is your 8 lb head that can get moving pretty damned fast in a crash.