A good office chair has armrests with width, depth, angle and height that fit the body, also the backrest shape fits the body to support natural movement. When a chair conforms with your shape, it naturally distributes your weight and relieves pressure, minimizing fatigue and tension in the body. Good airflow is also important much like the idea of flexibility, to keep you cool during long hours here, and with a combination of flexibility and support, you can focus more on your work and decrease fatigue as you spend more and more time sitting.