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Keyboard Ergonomics

Typing injury, a form of Repetitive Stress Injury (RSI), is a controversial topic. One school of thought is that physical damage from typing tends to creep up on you, starting as minor discomfort that barely registers. However, if you keep doing the things that cause injury, the problem will worsen. Tendinitis can develop. Muscles in the hands and arms may become irritated as well, a condition called myositis. As soft tissues become more inflamed and swollen, they can press on adjacent nerves, causing tingling, pain, and weakness in the fingers, and diminished motor control. Carpal Tunnel Syndrome in the wrist is a frequent complication of typing injury. Sometimes scar tissue will develop. The cumulative effect of all this can become permanently crippling.

Or not. Others believe that claims of Carpal Tunnel Syndrome and other afflictions blamed on computer typing are being grossly exaggerated; becoming a trendy disease, or even fraud.

Well, I suffer from typing pain myself, partly due to typing aggravating a more general problem with polyneuritis related to a chronic medical condition. I don't have the symptom profile associated with Carpal Tunnel Syndrome, but some keyboards will have me in severe pain (enough that I can't continue typing) in less than 10 minutes. Typing can leaves me in pain from my fingertips to shoulders for hours or days. However, on my good days some keyboards allow me to do moderate amounts of typing throughout the workday (taking breaks of course) without excessive discomfort. The difference appears to be keyboard design. Why do so many keyboards have such a long key-travel, stiff key springs, and a hard landing when the keys bottom out?

My favorite conventional keyboards that I've tried are the built-in ones on the PowerBook G3 Series, both WallStreet and Bronze. The beauty of the G3 Series keyboard is that the key travel is about 1/8 of an inch, and the touch is both feather-light and silky-smooth.

I find the Apple USB keyboards pretty decent and comfortable, and another keyboard I own, which I am typing on right now, is a MacAlly New Wave ADB ergonomic keyboard. This unit has a palm rest, and is one of the better inexpensive conventional keyboards that I have tried. However, it also suffers from what I consider some design flaws -- ones, I hasten to add, that are common to most computer keyboards.

One of these is that keyboard designers insist on inclining the keyboard's plane back to front, which is the exact opposite of what ergonomics specialists recommend. Is this a throwback to the days of manual typewriter keyboards? The MacAlly New Wave has a substantial incline even with the little feet at the back retracted, and the palm rest -- an otherwise great idea -- is rendered almost useless by being angled down away from the keys.

To compensate, I've duct-taped a strip of 5/8" plywood under the front of the keyboard to level the plane of the keys, and then another 5/16" strip on top of that under the palm rest. Those makeshift adjustments improved my comfort level using the keyboard substantially. The keys are still too stiff, have an annoying over-center action, and travel too far, but this is a keyboard that I find reasonably comfortable to use nevertheless.

Probably the worst keyboard I've used is the old pre-ADB one that came with the Mac Plus, 512k, et al. Those hard-bottoming keys make my hands numb in a few minutes. I find the same problem with the full-size Apple Keyboard II, which has a nice, light, key action, but which also bottoms out hard. The Apple ADB keyboards and the MacAlly New Wave all are membrane designs, which by nature of the keys bottoming on the soft membrane material have a softer landing.

When I got my PowerBook 5300 back in 1996, I used it with the little, retractable feet that elevate the back of the computer extended as a matter of course. It just "looked right" to have the keyboard angled toward me like the one on my old Remington typewriter.

The 5300 has a pretty mediocre keyboard, with a fairly stiff, rough action, although I still find it preferable to almost any conventional desktop keyboard because the key travel is short and the landing somewhat resilient. However, some research I did about typing injury and computer ergonomics during a really bad episode of hand pain informed me that a point of general consensus among many experts was that the keyboard should be flat and level to help flatten out the wrist angle, or even actually angled away from the user. I retracted the feet on the 5300, and while it felt a bit awkward at first, I soon became a convert when I discovered that my hands and wrists were significantly more comfortable in the flat position.

My daughter, who now owns the 5300, has gone a step farther than that, using a Road Tools Podium Coolpad with the elevation pedestals positioned on the nearside so that the PowerBook's keyboard is actually angled away from her, which she says she finds comfortable.

When the G3 Series PowerBooks were introduced, some users complained about their keyboard's flexible "springiness" -- not "solid-feeling" like the older PowerBooks. There were even instructions posted on Websites for reinforcing the G3's "flimsy-feeling" keyboard. Bad idea (for several reasons).

The G3 Series keyboards were actually state of the art -- flat plane, feather light touch, and short travel. Compared to most other keyboards, I find using them an almost sensual experience. I don't know whether the G3 Series keyboard's flexibility was intended to address the ergonomics issue or not, but it's a significant part of the reason why these PowerBooks are so easy on the hands.

At least one scientific study corroborates my subjective observation. Computer keyboards designed with "springy'' keys "can significantly reduce hand pain such as that associated with carpal tunnel syndrome," according to research by David Rempel of the ergonomics program at the University of California-San Francisco and the University of California-Berkeley.

Rempel's findings showed "that a significant reduction in symptoms is possible with a simple intervention -- using springs underneath each key that change the force or feel of the key switches.''

The 12-week study was conducted on 20 keyboard users at Lawrence Livermore National Laboratory who had reported symptoms associated with the onset of carpal tunnel syndrome.

Comparing a control group of test subjects using regular keyboards with another group using a ``springier'' keyboards, the researchers determined that keyboard design can play a critical role in managing hand and wrist pain.

Rempel's study used the "Protouch'' keyboard manufactured by the Key Tronic Corp. of Spokane, Washington, which produces of keyboards for PCs, terminals, and workstations, but unfortunately not for Macs.

Unfortunately, when I contacted KeyTronic a while back, I was told that they no longer manufacture the "Protouch" unit, which was not purpose-designed for ergonomics, but rather as an inexpensive entry-level unit. The "springiness" was told, was actually a result of leaving out certain parts that were included in Key Tronic's more expensive keyboards for reasons of economics -- not ergonomics.

However, there are several choices for Mac users in true ergonomic keyboards.

Part 2

Kinesis Keyboards

Comfort Keyboards

More Ergonomic Keyboards

Charles W. Moore

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