A chair includes a seating part having a forward direction in which an occupant of the chair faces when normally seated on the seating part. The seating part has a forward portion for horizontally supporting the thighs of the occupant. There are further provided a support structure secured to the seating part and extending downwardly therefrom; and a pivot axle formed of a bar secured to a lower part of the support structure. The pivot axle extends transversely to the forward direction and forms, by contact with a floor, a pivotal arrangement for providing a forward and a rearward swinging motion of the seating part and the support structure about a pivot axis situated below the seating part. The seating part and the support structure are free from a structural resetting arrangement, whereby the seating part and the support structure are exposed to pivotal forces derived solely from forces applied to the occupant's body.