Upper back Pain:
My back hurt for months. Upper back, mostly my neck, spine and across my shoulder blades. I was getting headaches too, that felt like they were caused by tension in my shoulders, but now I feel fine! I'm sharing this hoping someone else can benefit.
I felt like I was stooping while I sat at my desk at work, the monitors were a bit low with no height adjustment so I was bending forward to look at them which made the pain in my back feel worse.
Health and safety studies suggest that the height of your chair seat is adjusted so when sitting with your feet flat on the floor and your lower legs vertical, your knees bend at roughly 90 degrees so your thighs are horizontal or sloping slightly downward, your back should be vertical and supported by the back of the chair, and the arms of the chair should be raised to the height of your elbows so as to just support your forearms, basically sit up straight.
The page at: http://www.globaltotaloffice.com/ggi_08/adjusting_a_chair.html
gives a pretty good description of how to adjust an office chair for comfort, right up until step eleven where you forget all the settings you have made and change it all so it will fit underneath the desk.
All the other desk related instructions are about raising the chair or using a footrest if your feet don't reach the floor. None of them suggest what to do if you are too tall for your desk or how to dig a small trench in the floor so your thighs are actually touching the chair. I always wondered why many chair seats would tilt forward but not back (unlike the one in that link). No part of me ever touched the front of the seat as my knees were higher than the bit I sit on. Ignoring step eleven I now have my seat height correctly set for me, the whole seat gives support, the backrest supports my back and my feet rest comfortably on the floor.
This brings my chair arms to 27 inches off the floor when I am sitting on it; there is an inch or so spring movement as I sit down. I'm not massive, only just over six feet tall, but if I set the chair any lower than this my knees begin to hurt and my back feels like it's trying to curl up into a ball.
The top of the desk was 28¼ inches from the floor, and the clearance under the metal frame that runs along under the front of the desktop was 26 inches meaning the 27 inch high chair arms will not fit under the 26 inch desk.
The desk top
The metal rail underneath
The chair arms will not fit under the desk
Because the chair arms don't fit under the desk I was sitting too far away from it and I had to stoop forward to reach the keyboard. I was constantly resting my upper body weight on my elbows and forearms while using the keyboard and the mouse. My shoulder muscles were permanently tense both trying to hold the weight of my upper body off my elbows and support my head at its inclined angle.
Giving myself a raise:
So I wondered what it would be like if my desk was higher. Looking underneath it was only supported on four small adjustable feet fitted at the four corners of the frame. The adjustment is only for levelling, not for raising or lowering the desk. Office chairs adjust easily but most desks seem to be a fixed height. Just for a quick cheap test I brought some offcuts of 2 inch thick timber into work and slipped them under the desk feet to raise it by 2 inches.
Remember to take the coffee cup off the desk before lifting it, and anything else that might fall, and be careful of your lower back while you're doing it. It's best to get someone else to assist either by doing the lifting for you or by daring to be the one underneath and slip the wood into place under the desk. You only need to lift one corner at a time and not very far off the floor. Position it so the desk feet are away from the edges of the wood and it makes a stable enough support as long as you don't intend to climb on the desk or perform any vigorous activity on or against it. The desktop is now 30 inches from the floor with a clearance underneath of just under 28 inches.
Nearly two inches - timber is rough sawn at two inches and reduces by about a quarter inch when planed smooth.
Place a block under each corner
The new desk height
and found I could raise my chair a little more
I sat down and was able to slide the chair arms under the metal rail and sit right up to the desk, resting my forearms comfortably on the desktop. I moved the keyboard and mousemat away from the edge and toward the middle of the desk, and found I could raise my chair a little more. The back of the chair is now supporting my back rather than only touching me if I leaned backwards. Sitting there felt like that first day when you move up to big school and the furniture is larger than you are used to. Any crumbs from eating my sandwiches at my desk now fall neatly onto a napkin on the desk instead of mostly down the front of my trousers.
Relief from back pain:
The change in desk height doesn't look much different, but after just one day
of sitting upright and close to the desk my back felt good. My back felt good all evening when I was at home too, so much so that I was eager to get to work next morning to sit at my 'new' desk some more. After less than a week my back doesn't hurt, my spine no longer feels like I need to stretch it at the end of the day when I get in the car, and I feel taller when I walk. What a difference two inches makes! These bits of wood are staying.
Adjust the monitor height:
Now I realised that the monitors are a little low. There is no height adjustment. The stands do allow the screens to tilt back or forward and I can angle them to look straight at them, but I am looking down at a steeper angle than I want to. Health and safety studies recommend that the top of the monitor should be roughly at eye level. A quick measurement indicated that the monitors needed to come up by about two inches.
A day's test with them balancing on some more bits of offcut timber let me know that this was more comfortable. There are commercially available monitor stands but these are about four inches high and have a fairly large desk footprint. I wanted something tidier and different and I managed to combine three of my hobbies, woodwork, computers, and guitars. I'll write up the construction method of my monitor stands in another article.