Hover technology is a thing in 2015(1985) and it appears many places.
When Marty has troubles with Griff Tannan he borrows a young girl’s hover scooter and breaks off its handlebar. Hes able to put his skateboarding skills to use on the resulting hover board.
Griff and his gang chases Marty on their own hover boards. Griffs has a top of the line hover board labeled a Pit Bull. Though Marty clearly has to manually supply forward momentum to his, Griffs has miniature swivel-mount jet engines that (seem to) respond to the way he shifts his weight on the board.
George requires traction for a back problem, but this doesn’t ground him. A hover device clamps his ankles in place and responds to foot motions to move him around.
Hover tech is ideal for leaning control, like what controls a Segway. That’s just what seems to be working in the hoverboard and hovertraction devices. Lean in the direction you wish to travel, just like walking. No modality, just new skills to learn.