Abstract: Apparatus for indicating the angular position of a patient support surface such as a mattress relative to the direction of gravity is disclosed. An angle sensor mounted to a frame associates with the patient support surface to create an output responsive to changes in position relative to gravity. Circuitry transmits an output signal to activate a display of the angular position of the patient support, thereby indicating whether the angular position is within a predetermined range. Preferably, the apparatus has a circuit for activating an indicator light, which more preferably mounted above the patient support surface. In certain preferred embodiments the apparatus that comprises the light is connected to the headboard, or the like.