The invention relates to a chair having a seat structure formed by a frame member that defines a central opening. A flexible membrane extends across the central opening. A pair of support pads, one disposed on either side of the cross-beam member, is provided and arranged at a level below the central opening of the frame member. The support pads are arranged within the seat structure so as to be rearwardly disposed with respect to the front edge of the frame by a first distance and spaced apart from each other by a second distance, the first and second distances generally corresponding to the positioning of the ischicial tuberosity of a user when the user assumes a seated position engaging the seat structure.