US Patent 7600821 Seat

A seat provides a band-like support for the body sides of a user so as to reduce the supporting pressure on the user's lumbar and to hold the user's upper body stably. In this seat, the center of a load to be received in regions symmetrically divided to a vertical central line of the seat are positioned outside of a back region defined by left and right angulus inferior scapulae and by the upper ends of iliac bones. Moreover, the load ratios in the individual regions are not more than 25% in the region corresponding to a region extended downward from the back region.