The turntable technique that consists of moving a vinyl record forward and backward with your hand while the record is playing is called

The answer is Scratching.  This is the turntable technique that consists of moving a vinyl record forward and backward with your hand while the record is playing.  It is sometimes called Scrubbing.  This is a technique that Disc Jockeys used to to produce percussive or rhythmic sounds.

All of them are man made