As a chiropractor, I think a lot about posture. And one of the activities that seems to cause a lot of stress in most people's bodies is spending prolonged periods of time at a desk or computer. So I spend a lot of time talking to people about how to have proper posture at their desk or work station. So here is the skinny. You want to sit in a chair where your sacum, or your low back, touches the back of the chair. It's best to have a chair where you can really have good back support. You want a chair that's designed for your body. So that the seat is not too deep for you, or not too shallow. You want your knees to come close to the end of where the edge of the seat is. And you want your feet to be able to touch the ground.
Most of us sit on chairs with our feet up on the rung. Or tucked up under us. And we want to make sure that the feet are actually on the floor. So adjust the height of your chair so your weight is on two feet, and two (?). That'll really distribute the weight properly through your entire muscoskeletal system, and put the least amount of strain on your body.
So let's talk about keyboards. Many people put their keyboard on a desk. Either because they're using a laptop, or that's just where they put the keyboard tray. But it's really important when you're at a keyboard, that your shoulders are dropped. So this is how you should set it up. Your shoulders should be completely dropped. And your elbows should be dropped and resting at your side. You want a right angle at your elbow. And no break at your wrist. This means that your keyboard should be about the height of your elbows.
Most people have their keyboard a little bit higher. And you might think, well what's the difference? It's just a few inches higher. But the difference is that when you have to start using the mouse, you end up engaging the elbow and the shoulder muscles. And this causes isometric contraction in those muscles. And that can really add up to a lot of pain by the end of the day.
I recommend that people get keyboard trays. The kind that screw on under your desk. You can slide them out. Get a wide one so you can put your mouse on it too. This way when you don't need your keyboard you can slide it under your desk, but when you need it you can adjust it just for the height you need for your body.
Now let's talk about the screen. The middle of the screen should be exactly at eye level. Or maybe an inch below. Many of us are putting laptops or computers on desks and the screens are a little too low. And that means that we're flexing our head forward all day. And that puts enormous strain on our neck and our shoulders. So raise your screen up a little bit. So that the middle of the screen is right at eye level. You'll be glad you did it. It'll make a really big difference.