A chair assembly includes a back shell member including a laterally-extending top portion, a laterally-extending bottom portion and a pair of longitudinally-extending side portions extending between the top portion and the bottom portion and cooperating therewith the defined open space therebetween, and a cover having a first surface adapted to support a seated user and a second surface opposite the first surface, wherein the cover is positioned over the back shell member to cover at least a portion of the open space, and wherein the cover comprises an elastomeric material having a longitudinal direction compliance to lateral direction compliance ration of at least 3:1.