A seat support mechanism that is adapted to constrain motion of a bottom of a seat relative to a floor as the seat bottom moves up and down relative to the floor, where the seat has a seat back, and where the seat is constructed and arranged to support an occupant thereof above the floor, wherein the seat bottom has a front edge, and wherein the seat bottom supports the occupant's thighs with the knees in front of the front edge of the seat bottom. The seat support mechanism is constructed and arranged such that as the seat bottom is moved up and down, the seat support mechanism causes the seat bottom to pivot about a virtual lateral horizontal pivot axis located farther from the front edge of the seat bottom than the occupant's knees. The seat support mechanism is further constructed and arranged such that the back of the seat remains at a relatively constant angle to the floor as the seat bottom moves up and down and pivots.