Posture and desk setup

OSHA suggests sitting 50 to 100 cm from the screen; the Korean labour ministry's guideline asks for at least 40 cm.

Picture an evening spent typing a four-page school report. (This is a made-up example.) By the end your neck is stiff, one wrist aches a little, and you have been leaning towards the screen for an hour without noticing. Nothing dramatic happened. The same small strain simply repeated a few thousand times. This course teaches touch typing, where each finger has its own keys and the eyes stay on the screen, in six short units with a practice keyboard on every page. The chair and the desk come before the first key, though, because a bent wrist or a raised shoulder repeated all evening adds up.

What a relaxed body looks like at the desk

OSHA, the US Occupational Safety and Health Administration, calls it a neutral position. The joints line up naturally, so muscles, tendons and bones carry the least strain. Hands, wrists and forearms are straight, in line and roughly parallel to the floor. The head is level and faces forward. The shoulders relax and the upper arms hang at your sides, with the elbows close to the body and bent somewhere between 90 and 120 degrees. Your feet rest on the floor or on a footrest. The back is supported, the thighs are about level, and the knees sit at roughly the same height as the hips.

The keyboard sits straight ahead, at elbow height

Put the keyboard directly in front of you, at a height where your elbows are about level with it. OSHA describes what goes wrong otherwise. Too low, and you type with your wrists bent up. Too high, and your shoulders creep up towards your ears. Many keyboards have small feet at the back that tilt them up. Use them only if they make your wrists straighter, and fold them away if they bend the wrists more. Korea's Ministry of Employment and Labor has its own guideline for display screen work. It asks for a keyboard tilt of 5 to 15 degrees, a keyboard no thicker than 3 cm, and at least 15 cm of desk in front of it, so the wrists have somewhere to rest between bursts of typing.

Two guidelines, two sets of screen numbers

OSHA suggests sitting 20 to 40 inches (50 to 100 cm) from the screen. The top line of the screen should be at or slightly below eye level, and the centre of the screen 15 to 20 degrees below a level line of sight. The Korean guideline sets the minimum distance at 40 cm, lines the top of the screen up with the eyes, and puts your view of the work 10 to 15 degrees below horizontal. So the two agree on the direction and differ on the exact numbers. Neither is wrong. Both were written for a whole range of bodies and desks, and neither was measured for you. OSHA adds one more case: if you wear bifocals, you may need a lower screen so that you don't tilt your head back to read it.

Curved fingers, light keys

Once you start typing, keep the fingers curved, as if holding a small ball, with the fingertips resting lightly on the keys. Press lightly and let each key spring back. Hammering tires the hands and buys no speed at all. The Korean guideline adds a point that matters for anyone who types a lot: don't keep the wrists bent outwards for long. A wrist rest is for the pauses between sentences. It is not a place to pin your palms down while the fingers work.

No position stays good for an hour

No posture is good for hours on end. OSHA recommends small changes through the day: adjust the chair or the backrest, stretch the fingers, hands, arms and back, and stand up and walk for a few minutes now and then. People also blink less while they look at a screen. Rest your eyes by looking at something far away, such as a clock across the room, and blink. Then try the practice keyboard below. Its first lesson uses only F and J. Sit the way this page describes, put your index fingers on the two keys with bumps, and type the first line without looking down.