How to sit on a Chair?

Those who have to sit on a chair for long hours e g. business executive, judges and magistrates, students, clerks etc. should make sure that they are using the proper chair. The height of the chair should be such that while sitting on it, the feet are placed flat on the ground. The knees are at the same or a slightly higher level than the hips and the back is touching the back support of the chair. If for some reasons a high chair has to be used then a foot board should be placed under the feet to achieve the same effect.