Adjust your chair properly. Here’s how:
Stand in front of your chair and adjust the seat so that its highest point is just below your knee cap. Sit so that there is large enough space to fit a clenched fist between the front edge of the seat and the lower part of the legs. Ensure that the back rest supports the hollow of your lower back. Adjust the height of your chair so that your work surface is at elbow height when you are seated; determine elbow height by holding your arms straight down at your sides. Use a foot rest if, after adjusting the seat to the proper height, your feet still are not resting flat on the floor.
