Vibrators have been the friend of the female orgasm for over a century now. Back in the 1800s you could only get access to one via a doctor’s appointment. To cure your irrational woman feelings, hysteria. When they started selling them for home use in the 20th century, companies made up weird, fake uses for them; nail buffing tools,special attachments for vacuum cleaners, etc. One very popular way to market the vibrator was to call it a back massager.
Probably thousands of different vibrator have come and gone but there is one that has outlasted them all and maybe will go on into the future as the queen of vibrators: The Hitachi Magic Wand.