The Anal Impaler
To be used more sadistic, bolt or fix the spreader bar to the floor. Make them get all the way on their tip toes and then raised the dildo and insert as far as possible. If they now attempt to put their heel down to rest, the dildo will further penetrate them if they have room. If not they will be forced to remain on their tip toes totally impaled.
Note: Ankle restraints and dildo are sold separately. Any flared based dildo, less than 1.75 inches in diameter will work with the rod.