Level: Introductory Peter Seebach (crankyuser@seebs.plethora.net), Author, Freelance
04 May 2005 With aching hands and wrists, the cranky user writes about ergonomics, from in-home doctor visits to the proper time for font smoothing.
Most people, if you mention work-related injuries, think of vast machinery, hydraulic presses, gears, and missing or mangled limbs. In fact, computer-related injuries are pretty common (and I'm not just talking about dropping the monitor on your foot).
Ergonomics is a field full of superstitions and rumors. Fads are commonplace. People do a lot of things which may or may not really help; they even do a few things which hurt.
Failure to take ergonomics seriously can have real, permanent effects. Some people can no longer type on a keyboard. One woman at a newspaper where my mother worked was encouraged to bravely soldier on, typing even though her wrists hurt and she couldn't feel her fingers anymore. Now she's on lifetime disability and I think both she and the company regret it.
Ergonomics is only partially a vendor or employer problem, though. To a certain extent, it is up to users to take charge of their own postures. You, as a user, can do a lot of things -- and should be aware of many ergonomic issues, too.
One more thing: I'm a cranky user, not a doctor. I'm not qualified to give medical advice, just to pass on a few stories and examples. If you are experiencing pain, talk to a doctor.
Doctor, it hurts when I do this
One of the main things to realize is that physical dimensions vary from one person to another -- human specifications are an extremely individual thing. The excellent advice that worked for someone else could injure you. So, rule one: If it hurts, stop. Doesn't matter how brilliant the theory is -- if it hurts, STOP. Talk with a doctor about it, but don't do it anymore. (One possible exception might be those rare cases when you need to train your muscles -- and some people have difficulty distinguishing among muscle pain, strain, and fatigue. Even so, don't push it. If it starts to hurt, take a break.)
Sometimes, it's impossible to take a break. You have a deadline or a similar human-defined schedule milepost that looms. In these cases, a little judgment goes a long way. Don't let people assume that you can just work a little harder and then go back to normal. I once had a minor hand injury cripple my writing work for about two months. Be prepared to spend a long time favoring an injured hand or wrist, taking extra care not to overload it.
It's a typing injury; I fell on the way to the computer
People generally associate typing injuries with, well, typing. That's pretty reasonable most of the time, but it's important to realize that anything you
do with your hands may have an impact on them. While I've had a number of mild run-ins with typing-related injuries, it was trying to open a locked rackmount case with a pair of pliers that impeded my typing ability more than any other strain. And if you've injured your hands typing or using a mouse or pointer, you may find that other hand/wrist activities are impacted substantially.
A little word about mice. You can choose among several kinds of pointing devices; only some of them are mice. Trackballs come in a couple of different types -- some are supposed to be moved with your thumb, others with your fingers. Unfortunately for left-handers, many trackballs are very clearly right-handed. If you use a pointing device a lot, make a point (the pun is intended) to try different types to see which ones work for you.
I can't use an actual mouse for long without serious pain; my mother can't use a trackball. Almost no one I know likes trackpads, but the people who do will use them even on desktop systems. The only thing I've generally seen agreement on is that almost all artists love drawing tablets.
Take five!
It is hard to overstate the importance of regular breaks. You can find a lot of software that encourages you to take regular breaks from working. This isn't just about typing, but also about eyestrain, stretching your legs, and getting up and moving around. The degree to which regular breaks matter depends on your work habits. If you take irregular breaks constantly, it may not matter that much.
How and when you take a break leaves a lot of room for personal style. I mostly use a fairly simple X11 program called xwrits (see Resources) to remind me to take breaks from typing. It's easy enough to tell it to not bug me and come back later, so I've been known to postpone my hourly rest break for as much as five hours (not a healthy idea).
On the other hand, a program which you can't pause could be problematic; if you're a system administrator trying to fix a security hole, you might not appreciate a 10-minute delay.
One feature that only some programs have is network awareness. If you work with multiple computers, you might easily take a so-called break from one to work on another machine. I do this sometimes. Once again, it's not healthy. If possible, get up and walk around. Looking into the distance is good, too; it helps you relax your eyes.
Red, tired eyes and that pounding in my head
Tiny fonts are a particular nuisance. I am a habitual user of high-resolution displays and large fonts. I find tiny fonts to be very obnoxious. Back when
I used Quicken, I dreaded accounting work because it required me to read what was probably a 9-point font. My display was set so 12-point fonts were a little small but quite readable; a 9-point font was really not viable. (Of course, it wasn't really 9 points, it was 9 pixels. On my high-resolution display, it was probably 6 points.)
Reading is nearly automatic for most people. They tend not to notice immediately when it becomes difficult; but hurt themselves as they continue to look. A co-worker at
one job used the standard fixed font that is a default for xterm and complained of headaches regularly. When I convinced him to switch to an 18-point font, his headaches stopped.
Firefox and Mozilla have a feature that lets you specify a minimum font size so that no text will ever be rendered smaller than this size. This is a wonderful
feature. I have it set to 18 points -- I'm not kidding. Eighteen points is about right for my display, making all text fairly clear and legible. A lot of
pages look badly formatted. Perhaps more ominously, a number of corporate pages look a lot worse when you can actually read the fine print they've tried to hide behind a tiny font, but this is a question of ethics, not aesthetics.
All programs should let you choose fonts -- it is simply impossible to pick a font which is reasonable for all displays and all eyes. Of particular note is that the lowest common denominator approach, so good in many aspects of computer design, leaves people squinting to see teeny-tiny fonts that would probably look good on a 640 x 480 display.
Smooth out the edges of letters
The benefits of font smoothing are debatable. Many people swear by it; I like it some of the time.
Recently though, when I looked at high-resolution LCD displays, I noticed that they all looked atrocious. I had to really stare to read the standard text on the display. Then I got an insight -- the blurring looked almost like it might be intentional. I turned off font smoothing and suddenly everything was sharp and clear.
This was on a Windows machine in a store. To see what a display looks like without smoothing, here are quick instructions (instructions for your operating system might be different):
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Right-click on the desktop, and select Properties.
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Select the Appearance tab.
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Click Effects.
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Uncheck smooth fonts with ClearType in the pop-up window.
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Click OK.
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Click Apply in the main Properties control panel.
On these sample machines, this change turned blurry dark-grey text into crisp, clear black text. I'll accept a few "jaggies" to be able to read the text easily. In general, font smoothing hurts legibility on small fonts while improving it on large fonts. On the Mac, you can specify a minimum size for font-smoothing. I am inclined to turn it off in most cases.
Monitor the graphic situation
High-res displays also leave you with graphic size problems. A lot of Web pages carefully designed to be elegant and legible on a 1024 x 768 display, or even 800 x 600, look like ant tracks on a higher-resolution display. This is one of the cases where graphical buttons which just contain a word are particularly odious.
It is hard to do anything about this. If the graphic is too small, it's notoriously difficult to make it look much better (although displaying it enlarged may help you make out details). If all else fails, go to a lower resolution -- although this makes a bigger difference on a CRT than it does on an LCD. You can run most CRT displays at resolutions that are really beyond their capabilities. The advertised best resolution is often a very poor choice. My 19-inch monitor, which looks a bit blurry at 1600 x 1200, can theoretically do 2048 x 1536, but it can't display individual pixels distinctly at that resolution!
The correct adjustment of your monitor is especially important for graphics. Most text is high-contrast even on a poorly adjusted display. Graphics, by
contrast, are easy to render unusable. (That pun was unintended.) If your hardware supports gamma correction, use that. Most displays that have settings for brightness and contrast are at their best with the contrast turned up almost all the way and the brightness set just dark enough that you can't see the edges of the scan area when displaying black pixels. If it goes any brighter than that, you lose some of your contrast range.
A badly adjusted monitor can really hurt. Monitor quality, especially LCD quality, has improved incredibly over the last few years. When I got a new LCD display, my CRT went instantly from being the good monitor I do my serious work on to being the not-so-good monitor I use for plain text. If you're suffering serious eyestrain, consider a new monitor.
Coming up next...
You have lots of options to adjust a system and make it less painful to use. Next month, I'll look at some of the things that are sold as possible
solutions, whole or partial, to ergonomic problems, and evaluate some advice for trying them out.
This week's action item: Adjust your display and experiment with resolutions and settings such as font smoothing. Pick a new font. Experiment.
Resources
About the author  | 
| | Peter Seebach has been using computers for years and is gradually
becoming acclimated. He still doesn't know why mice need to be cleaned
so often, though. You can contact Peter at crankyuser@seebs.plethora.net. |
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