If you work at a computer you are in danger of repitive strain injury (RSI). Setting up an ergonomic work station can be crucial to your health and happiness.

Check out my other various ergonomic Instructables:
Stand Up Desk, Standing Desk, How to make a vertical, ergonomic (tie-fighter) keyboard, and Create an Ergonomic Standing Desk and Office on the Go.

Step 1: Research, Experiment, and Listen

RSI is typically the result of a mismatch between what your body evolved to do, and what you are actually doing. In their natural state, humans collect fruits and vegetables, hunt game, carry their young, and explore their surroundings. To succeed in the modern world, humans sit still, focus on a tiny area for long periods of time, slam their fingers repeatedly against artificial surfaces, and ignore their surroundings. Unfortunately, building up the resources and free time to explore our surroundings often means hammering out that last bit of code, or finishing up a document with just another thousand mouse clicks.

This project documents what I have done to control my RSI. Controlling yours will be different and you will need to research, experiment, and listen to your body.

Resources I found useful: "Repetitive Strain Injury : A Computer User's Guide" by Emil Pascarelli and Deborah Quilter. Both authors have new books that are probably also good. Hand University has great pictures of the wrist to help you understand what might be inflamed. The ATIC Lab at MIT has resources and also allows students to borrow various keyboards and pointing devices to try them out, which is truly invaluable.

For me, the hardest part of this process was listening to my body. The pain usually does not come immediately, so it is often very difficult to determine what activity caused it. What I found is that pain is not discrete. There are levels of feeling before true pain that can signal distress or damage. Generally, these manifest themselves as "being aware" of some part of your body. For example, after typing on a small or badly positioned keyboard I will become aware of my wrists; I try to recognize these signals and take a break or stop to prevent progressing into pain.

Step 2: Take Frequent Breaks

You were not designed to type all day long. You need to take breaks.

I use Workrave to help remind me to pause. It has multiple timers that are only active when you are mousing and typing and can be set to actually prevent you from overusing your computer, if you desire.

I have a micro-pause of 45 seconds for every 3 minutes of typing/mousing, and a 10 minute rest-break for every 30 minutes when I stretch, walk around, and do non-computer-related work. This may seem maddening, but it works for me. The frequent micro-pauses are not even lost time; while pausing, I think about the next thing I am going to write or do and can do it quickly and directly when the pause is over. They also come with plenty of warning, so I can scroll to the next page of a document and continue reading with my hands at rest.

Although it may seem like you are pulse-width modulating your work with breaks, I have found my productivity equal or better than before I took breaks. With your computer telling you to take breaks, you can get angry at it and not at your hands when they force you to stop.

Now that I work primarily on a Mac, I've been using AntiRSI. It doesn't have the same level of control as Workrave (30 second micro pauses are the max!), but accomplishes nearly the same goal.

Step 3: Stretch

During my rest breaks and whenever I feel stiff, I stretch my wrists. With so many stretches available, you'll need to pay close attention to make sure you are getting a proper stretch on the right muscle group. I fine-tuned my specific set of stretches with a physical therapist.

I hold each of these for 30 seconds or longer. With one hand straight out in front of me and my fingers pointed down, I pull my fingers towards my body to stretch the inside of my forearms. Next, I put my arms out from my sides, make fists, and bend my wrists downwards to stretch the outside of my forearms. Occasionally, with the backside of my hands, I push against something solid to get an even deeper stretch. With my fingers pointed away from me, I twist my hands at the wrist around my forearms once in each direction. I finish up by hanging from a pull-up bar or something similar for 30 seconds with straight arms and 30 seconds with my arms bent -- this part often feels great as my weight pulls straight through my wrists.

Step 4: Position Your Arms

Position your keyboard and mouse such that your forearms are horizontal and your upper arms vertical. The weight of your hands and arms should be supported by your shoulder muscles and not resting on any surface of the keyboard while typing. Your hands should be floating above the keyboard surface. Try to achieve the same position when mousing. Resting your hands or wrists on a "wrist rest" and then asking your tendons to do fine motor control by typing is bad news. When resting, you can use the wrist rest or place your hands in your lap.

To dial in the proper height, I use under-desk keyboard drawers such as the Kensington 60044 and 3M AKT200SL. On both of these models, I've removed the gel-filled wrist rests so that my keyboard fits properly. An important feature is that the mouse platform is independent of the keyboard platform. It is unlikely that your keyboard and mouse will be perfectly positioned for you at the same level or angle. I prefer the Kensington because it is continuously adjustable while the 3M has detents.

After taking breaks, I consider arm position the most important thing. When I'm forced to use a laptop, I put the computer in my lap and make sure not to rest my arms on it while typing.

Step 5: Choice of Keyboard and Mouse

Keyboards and mice can be quite expensive, and trying them out at a store is not enough. I can't stress enough how wonderful it was to borrow different devices from the MIT ATIC lab. See if you can borrow devices from an RSI support group, or start your own.

I decided on a Goldtouch keyboard and 3M Ergonomic mouse. I felt that many of my problems stemmed from rotating my hands from a neutral, handshake-like position to a flat, fingers down position to type and mouse. This keyboard and mouse lets me work in a position closer to neutral.

These devices are not perfect. Previously, I used a Microsoft split keyboard and a Logitech trackball (Logitech Cordless Trackman FX Optical Trackball, which appears to be discontinued). Something that works for you now may not work in a year. My thinking on this is blunt: Each device overuses and destroys a different set of tendons and muscles, and to keep working, you may have to cycle through which set is currently being wrecked while another heals.

Step 6: Use Two Mice at Once

If using a mouse hurts your hands, trying using two mice to switch hands. Right now, I have left and right-handed Evoluent Vertical mice, and I switch between them frequently. Since both my hands go back to the keyboard, it's natural to reach for a mouse with the hand that wasn't last typing. Being ambidextrous helps, but you can learn to mouse with your other hand pretty quick.

I just picked up a Wireless Right Handed Vertical Mouse Version 3 and tried to use it in combination with my Version 2 Left Handed mouse. While the two mice still work together, they are different! The buttons have been changed between versions: version 2 has its right-click button in the center, while version 3 has it on the bottom of the stack of buttons! Also, the resolutions of the mice are different, so moving the left mouse causes less cursor movement than moving the right mouse. Since my computer doesn't know I'm using two mice, there's no way to compensate! Though, I've sorted out the button issue by using USB OverDrive to map both second and third buttons to "right click." If you plan to use two mice, make sure they are the resolution and button layout.

Step 7: Position Your Screen

Position your screen so that when your neck is straight you are able to look horizontally to the approximate top of the screen. Your head is heavy! Looking down towards a low desk or into your lap all day can make your lower back really sore.

I built special stands for my laptop and monitor. As an aside, using two monitors is great; your eye can more easily refocus on something new when you look in a different spot then when you flash open another program window, and there's no key-strokes involved.

Step 8: Sit Up Straight But Move Around

Another factor in preventing back pain is sitting up straight while still moving around. I sit on an inflated ball from FitterFirst that keeps me moving and shifting throughout the day. If you slouch into a chair and let it support your back all day, those muscles get weak and prone to being "pulled" by even the simplest tasks.

I used to use a kneel chair but decided I didn't want the constant pressure on my knees.

Step 9: Manage Pain

When you've gone too far, manage the pain. I apply ice directly to the sore tendon and hold it there with thin rubber bands. 5 minutes is usually enough. Make sure not to overdo it -- you can get frostbite!

Some people swear by Ibuprofen for its anti-inflammatory capabilities. Personally, I am weary of taking a pain-killer because it may allow me to ignore the pain and truly damage myself. See what works for you.

I have been experimenting with curcuminoids, which are found in turmeric. They have anti-inflammatory effects, but no pain-killing. Jury is still out!

UPDATE - The curcuminoids had no effect. However, what has been remarkably useful is fish oil capsules. EPA, one of the omega-3 fatty acids found in fish oil, acts as an anti-inflammatory. 2000 mg of fish oil twice a day makes my wrists feel normal even after a full day of typing. Though, I can still overdo it: My stretch break program was inadvertently turned off for half a day and I hurt afterwards. Lots of people are now recommending fish oil for overall good health, so there's no harm in giving it a try.

Step 10: Improve

Ask someone to take pictures or a video of you working. Be objective and try to improve.

Don't be embarrassed by your crazy-looking setup. People will make fun of you, but that's easier to take than the pain.

Step 11: Other Factors and Ancedotes

Being overweight, leading a sedentary life, smoking, and being chronically dehydrated increase the serverity of RSI. Eating well, exercising, and sleeping enough will help. These things should be obvious.

I once had an RSI flare-up after using the stupid track-point on my laptop for 3 hours straight in a boring meeting. A tendon that controls my thumb or first finger became so seriously inflamed that the pressure required to pick up a pen with my thumb and first finger was enough to bring tears to my eyes. However, it was was the frustration of having a useless hand that would make me cry out.

I swore off computers for three weeks. My loving wife typed the few email responses that were actually critical or couldn't be done with a phone call. Luckily, the third week coincided with a kitesurfing vacation. After a full week on the water, the tendon healed. Since implementing all of these techniques, it hasn't bothered me since (other tendons still give me problems, but not nearly as severe).

I went to physical therapy for a while and decided it was a mixed bag. The ultrasound and massages were not really helping me. However, they did determine that my wrists and fingers are hypermobile, which is why some of the standard RSI stretches were not working for me.

As an experiment, I gave up cycling to work and took the bus. Without the exercise and relaxation of biking, my wrists felt much worse. They promptly improved once I started biking again.