Image Number 2 for United States Patent #5300004.
A device providing a sensory indication that the hands of a user executing a sit-up have moved a selected distance desired for proper execution of the sit-up, including an adjustable width base plate having substantially parallel channels disposed on opposite sides thereof, and slide plates disposed in each channel and having an upper surface engageable with the hands of a user, the slide plates being movable the selected distance in the channels between the channel ends. Users of the device consistently, uniformly perform a sit-up which minimizes unnecessary strain on the person's back by first positioning themselves in a starting position on their backs and on the device with their arms extended lengthwise of and parallel to their body. Their hands are then positioned on top of the slide plate positioned with its back end abutting the trailing end of the channel. Each sit-up is then performed by the person elevating his head and shoulders to cause lengthwise movement of his arms which in turn moves the plate in the channel, halting the elevating of his head and shoulders upon feeling the front end of the slide plate strike the leading end of the channel, and finally lowering his head and shoulders to the starting position.