The first time I saw a door designed this way was in a men’s restroom at a restaurant. A cast iron plate stuck out from the bottom of the door – slip your shoe underneath and pull the door open. Someone decided this would be an improvement on the sanitary technique of grasping the door handle with a paper towel.
I don’t think the principle has been taken far enough. Opening a door with an armload of boxes is a trick. Lever-style handles manipulate without too much trouble. But far too often I find myself wedging my load against the doorjamb, slipping a hand out and swinging the door open before gravity yanks its inertial chain.
Imagine a door with a “handle” at foot-level. I suppose that makes it a “footle” or a foot-knob. You could step on the latch to push the door open, or pull it up to operate it in the other direction.
Of course, a door handle of this nature could cause temporary imbalance. However, if you’ve got a balance problem, just use the conventional handle.
It would appear (from page 1 of my Google search) that most design solutions aim at the sanitary benefits. This is such a narrow application, especially because they involve free swinging doors only.
Residential front doors are an obvious next step.
The next time you try to use a door with both hands full, consider how simple it would be if you could just use your foot instead.