A seat cushion for a chair has a plurality of cushion grooves deformed a seat load of a user formed in a central portion of a lower surface thereof, the plurality of cushion grooves include: a plurality of main cushion grooves disposed in a plurality of rows in a front-rear direction and a left-right direction and spaced an equal interval from each other; and a plurality of sub-cushion grooves each connecting one of the plurality of main cushion grooves and formed in a straight shape with narrower widths and smaller depths than the plurality of main cushion grooves.

The utility model discloses a comfortable chair suitable for multiple usage postures. An overturnable desk board is arranged on a chair backrest, and a desk board adjustment mechanism can fix the angle of the desk board and support the desk board. The chair is provided with overturnable chair armrests, and armrest angle adjustment mechanisms can adjust the angle of the armrests, so as to provide users with various usage postures, realizing high flexibility and practicality. Embedded armrests are also arranged on the chair armrests and can be equipped with matching small desk boards. With embedded armrest adjustment mechanisms, the embedded armrests can be adjusted in both height and forward/backward position, so as to cater to users of different body types and heights.

The utility model discloses a comfortable chair suitable for multiple usage postures. An overturnable desk board is arranged on a chair backrest, and a desk board adjustment mechanism can fix the angle of the desk board and support the desk board. The chair is provided with overturnable chair armrests, and armrest angle adjustment mechanisms can adjust the angle of the armrests, so as to provide users with various usage postures, realizing high flexibility and practicality. Embedded armrests are also arranged on the chair armrests and can be equipped with matching small desk boards. With embedded armrest adjustment mechanisms, the embedded armrests can be adjusted in both height and forward/backward position, so as to cater to users of different body types and heights.