Abstract: A chair includes a base, a seat supported on the base and defining right and left sides, and an armrest. The armrest includes an armrest support rotatably supported under the seat on a bearing mechanism on the base for 360.degree. of movement around the seat, including movement to positions adjacent the right and left sides of the seat. The seat is slidably supported on the base for movement between a forward use position and a rearward position, the rearward position permitting increased clearance in front of the seat for adjustment of the armrest, but the seat being normally biased toward the forward position by a spring device. The base includes a control for supporting a reclineable back.