Doorknobs

So I have a new theory. You know how some doorknobs are round and rotatable, while some have a long part to press down? And how the long sort can be opened with an elbow? Whereas with the round ones you have to have at least one free hand? Well I do believe the little round kind are made to prevent you from dying on a staircase. For example, if you are carrying a multitude of packages for, say, christmas or something, you will be forced to make two trips to carry all of them if the doors cannot be opened with an elbow. However, the likelihood of tripping down the staircase is decreased. Thus a round doorknob saved my life, hypothetically.
Merry Christmas everyone.