Abstract: A back support means which may be detachably positioned on a mattress comprising a bottom sheet having a width to cover the central portion of a mattress and extending across the width of said mattress, which bottom sheet along with a top sheet form an open-ended pillow receptacle substantially extending the width of said bottom sheet. Within the open-ended pillow receptacle is placed a pillow of a size substantially conforming to the interior of the open-ended receptacle. The pillow is filled with shredded polymeric foam, preferably a rigid or semi-rigid shredded polystyrene foam.