Abstract: The invention provides a back support for supporting a mattress on a bed having a bed base. The back support comprising a generally rectangular frame, a plurality of strap fittings and a corresponding plurality of individually adjustable straps. The generally rectangular frame have side members. The plurality of strap fittings are arrangable along the side members of said frame. The corresponding plurality of individually adjustable straps are attachable to said strap fittings to extend laterally between said side members (i.e. extending laterally of the mattress in use) for supporting the mattress. The back support is adapted to be placed onto the bed base to lie between the bed base and the mattress.