Support device for supporting a body or a part of a body, in particular of a human body, comprising at least one deformable element with a first face and a second face opposite each other and provided with at least one detection means for detecting deformations of said deformable element, in which the detection means comprises: a substrate sheet (20), which is connected to one of the faces of said deformable element (6) extending parallel thereto and is provided with a plurality of metal windings (19) formed flat on at least one face of this substrate sheet, and a plurality of metal pellets (28), which are connected to the other face of said deformable element.