An automatic back scratcher is a device that can scratch a person's back without requiring the person to perform a physical movement. This is usually while he is laying in bed. The back scratcher can also be used while standing if the person cannot reach his back.
Some automatic back scratchers operate either from a battery or through an electric outlet. Automatic back scratchers tend to be used by the elderly and by patients in nursing homes.
A "SpongeBob SquarePants" episode that originally aired in 2006 featured an invention known as the Automatic Back Scratcher, Hair Comber, Nose Picker, Ukelele Tuner 9000.