"...in fifty years, do you believe that people will be recognizably human?"
- Greg Bear
Auto-Car
A personal vehicle for indoor and outdoor use.
In the world of this story, most human beings had given up walking.
... the Academy of Natural Sciences in Philadelphia was filled with the usual throng of pleasure seekers, each in his own auto-car.
(The Autocar from The Revolt of the Pedestrians)
Noiselessly, on rubber-tired wheels, they journeyed down the long aisles, pausing now and then before this exhibit or that which attracted their individual attention... Finally, a boy stopped his auto-car in front of a glass case.
"What is that, Father? They look as we do, only what peculiar shapes."
"That, my son, is a family of pedestrians... This family was shot in the Ozark mountains. It is believed they were the last in the world..."
The automobile had developed as legs had atrophied. No longer content to use it constantly outdoors, the Successors of Ford had perfected the smaller individual machine for use indoors, all steps being replaced by curving ascending passages. Men thus came to live within metal bodies, which they left only for sleep. Gradually, partly through necessity and partly through inclination, the automobile was used in sport as well as in play. Special types were developed for golf ; children seated in autocars rolled hoops through shady parks ; lazily, prostrate on one, a maiden drifted through the tropical waters of a Florida resort. Mankind had ceased to use their lower limbs.
I think that this is a spot-on prediction of the increasing use of "scooters" by people who should be healthy but have given up walking for reasons of obesity or laziness.
In the 2008 movie Wall-e, the entire population has given up walking:
Should AIs and AI Robots Demand Rights?
'This robot is a creature... It is a manlike being. Therefore, like any other talking, thinking man, he is entitled to a court trial!'