Abstract: A chair comprising a frame having a seat portion and a back portion is adapted to support the trunk of the body of an occupant. The frame is supported on a base. The chair includes a mechanism for allowing that part of the body portion supporting the upper trunk of the body of the occupant to tilt relative to that part of the back portion supporting the lower trunk of the body of the occupant and the seat portion. The chair also includes a mechanism for allowing the seat portion to tilt relative to the base. The tilt axis is located underneath and substantially adjacent to the anterior end of the seat portion. The back portion includes a pair of oppositely disposed tubular arms that define side members of the frame. Each of the tubular arms is discontinuous at a point adjacent the lumbar region of the seated occupant. The back portion tilting mechanism comprises a pair of coiled springs each tightly inserted within the respective tubular arm and extending across the respective point of discontinuity.