Motorized adjustable support device for a padding of a seat and / or reclining furniture, for example, a bed mattress, with a first support part (4) and at least a second support part (6, 8) for the flat support of the padding, the first support part (4) and the second support part (6, 8) being joined together in an articulated manner and can be pivoted with respect to the other by means of actuating means, being arranged in the first support part (4) a plurality of slats (62, 64) parallel and separated from each other, the actuation means having at least one electromotorized actuator and the electromotorized actuator being arranged in the first support part (4) so that that an actuator transmission member is disposed between an upper delimitation plane and a lower delimitation plane of the first support part (4), characterized in that the actuator is arranged essentially in a c complete between the upper delimitation plane and the lower delimitation plane of the first support part (4), because the actuator is a linear actuator and because the transmission element of the linear actuator is a spindle nut which is secured by fixed way in front of a rotation and so that it can be moved in the direction of screwing on a threaded spindle (52) that can be driven by a turn by an electric motor (50) and by which the spindle nut is in a active connection with a pivoting mechanism for pivoting at least one of the support parts (6, 8) with respect to the first support part (4).Dispositivo de apoyo ajustable motorizado para un acolchado de un mueble de asiento y/o reclinable, por ejemplo, un colchón de una cama, con una primera parte de apoyo (4) y al menos una segunda parte de apoyo (6, 8) para el apoyo plano del acolchado, estando unidas entre sí la primera parte de apoyo (4) y la segunda parte de apoyo (6, 8) de manera articulada y pudiendo hacerse pivotar una con respecto a la otra mediante medios de accionamiento, estando dispuesta en la primera parte de apoyo (4) una plur
