The crossmembers 4 contain fixing holes (not shown) distributed, optionally uniformly, all the way along their length to enable support 1 to be fastened, for example by screws, to the floor and/or to the wall, avoiding possible obstacles such as holes or pipes.The mounting and hinging arrangement of the structure 100 also includes a hinge pin 5 (not shown in FIG. 1) approximately perpendicular to