What movie is this? Alien living as humans

I can’t remember the name of this movie, but is old, from the 1960’s or 70’s. It was about a community hidden out in the boonies. Maybe farmers. A couple visits this community, probably to study them. These people are taught that they can not raise their feet, thus when they walk, they drag their feet. There is one scene where some kids are floating; that may be what happens when they do not drag their feet. They are actually aliens that were stranded on Earth, living as humans for a couple / several generations. Offspring where the ones not allowed to walk normal but instead drag their feet.

The outsider Female might have been a teacher or a doctor.