<p>Chair member for promoting correct posture. The chair member may form the chair seat (2) or back rest (4) or it may be a portable cushion. The seat embodiment includes a forward support portion (6) of relatively high density resilient material and an adjacent rear support portion (7) of relatively low density resilient material, differential deformation of the two portions locates an occupant's ischial tuberosity behind the forward support portion (6) which thereby resists forward movement of the sitter from the chair.</p>
