What is the correct ergonomic height for my desk, computer monitor and office chair?

THE CHAIR

Move the chair AWAY FROM THE DESK.

1. Sit back in the chair with your back positioned properly against the chair backrest.
2. Check that the gap between the inside of your knees and the front edge of the seat. It should be about 3 fingers wide. If it is more than 3 fingers wide, increase the depth of the seat by adjusting the seat slider forward to extend the seat depth. If it is less than 3 fingers wide, adjust the seat slider backwards to shorten or reduce the depth of the seat.
3. Now adjust the height of the chair. The correct chair height is when both your feet (with shoes), are flat on the floor and your knees are slightly lower than the level of your hips. By sitting with your knees below the level of your hips you reduce the rotation of the pelvis which in turn reduces the pressure in the lumbar discs. What happens when you sit?
4. Adjust the height of the armrests so that when your forearms rest on the arm pads, your elbows are bent at approximately 90⁰. Your shoulders should be relaxed and comfortable – in other words you should not have to lift your shoulders (armrests too high) or let them droop downwards (armrest too low).
5. Adjust the width of the armrests to suit your body shape. Ideally the arm pads should be positioned so that your upper arm is vertical and not extended too far outwards away from your body.
6. Rotate the arm pads so that your forearms rest comfortably over the full extent of the arm pad.
7. Adjust the tension of the swivel mechanism so that it suits your body weight. When you relax in the chair, you should easily be able to recline backwards without using excessive force. As you recline, the spring tension should “balance” your weight.
8. Adjust the height of the backrest and/or the position of the lumbar support so that it fits snugly in the lumbar region of your back. Ensure that you keep the spine in a natural position. Don’t over or under accentuate the inward curvature of your spine. Back support for office chairs.
9. Adjust the headrest into a comfortable position. Tip: Placing your head back and touching the headrest forces you to push your shoulders into the backrest and lift up your chest. This lifts your diaphragm which enables you to breathe better. Improved breathing leads to better concentration.

Now (and only now), move the chair towards the desk.

THE DESK

1. The top of the armrests should be inline with the surface of the desk. In other words, just like your forearms were resting comfortably on the arm pads, they should now rest comfortably on the desk with your elbows bent at about 90⁰.
2. If your elbows are bent at an angle much greater than 90⁰, the desk is too low. RAISE THE HEIGHT OF THE DESK.
   Do not lower the chair height because you will then sit with your knees above the level of your hips which will increase the pressure in the lumbar discs and quickly result in back pain. Furthermore, you will automatically hunch your back resulting in shoulder and neck pain. This is VERY IMPORTANT. If the desk is not height adjustable, use blocks of wood, old books, reams of paper etc, to raise the height of the desk.
3. If your elbows are bent at an angle much less than 90⁰, the desk is too high. Lower the height of the desk. If the desk is not height adjustable, then RAISE THE HEIGHT OF THE CHAIR. This means that your feet will no longer be flat on the floor, so use a FOOTREST to support your feet. DO NOT let your feet dangle in the air.
4. If you need to sit closer to the desk and only use the desk to support your forearms, lower the armrests so that they are under the desk when you work. Alternatively slide the arm pads backwards to allow you to sit closer to the desk.
5. If you work with papers, you may want to consider using a document holder. What are the health benefits of a document holder?

THE MONITOR

1. Adjust the height and distance of your monitor so that the top of the screen is at eye level and about an arms-length away.
2. If you use 2 monitors, position them equally from you. Ergonomics in the workplace.

RELAXING IN THE CHAIR

Release the synchronous or free-float mechanism and tilt fully backwards in the chair to increase the angle between your thighs and torso. By changing this angle, you automatically stimulate, or activate numerous muscles in your lower back, core and legs. As a result, the blood flow through these muscles increases, bringing oxygen and other nutrients to the muscles and carrying away the waste products of muscle metabolism. By doing so, muscle fatigue and it’s associated pain is reduced, particularly in the lower back. This is known as Dynamic Sitting.