A load support member includes spaced apart beam members, a linking member and a stop member. In another aspect, the beam includes a support surface defining first and second landing regions, which are in contact with and support a membrane. In another aspect, a brace member is secured between laterally spaced beams, with the brace member having a greater height than width at the end thereof and a greater width than height at the middle thereof. In another aspect, a pair of armrests are joined to a cross member and a pair of spaced apart beams in a releasable engagement. In yet another aspect, a pair of beam members are fixedly joined with a cross member, which is pivotally connected to a link pivotally connected to the beams. A method of assembling a load support structure is also provided.