KB's and RSI/carpal tunnel syndrome (was Re: Apples and RSI...)

[Rubywand <rubywand@swbell.net>]

Dave Althoff writes ...
> 
> Yesterday, I had an eye-opening experience.
> 
> I've been using computers extensively since about 1981. ....
>
> So I have been using various Apple ]['s for about sixteen years ....
> 
> I would expect that I should have some sign of RSI by now.  But
> d'ya know something?  I don't.  My fingers can break-dance, and my wrists
> don't care at all one bit.
> 
> A few weeks ago, I had a marathon session (total of about nine hours) on a
> Macintosh and on my GS.  I was retouching photographs on the Mac so that I
> could include them in a GraphicWriter III document, so I was doing some
> extensive mousing with both the Mac and the IIgs.  Okay, so no problem.
> 
> Yesterday, I spent about 90 minutes on a PC, running Corel PhotoPaint with
> a Microsoft "ergonomic" mouse, retouching scanned logos that I wanted
> to use with our video character generator (Chyron pc-CODI, if that
> means anything to you).  By the time I went home, I could scarcely move my
> hand.  In fact, it still hurts a little.
> 
> Now I begin to put 2+2 together, and realize something that we've known
> all along.  I have been typing, mostly on computers, for about sixteen
> years.  In that time, my computer use has been almost (but not
> quite) exclusevely Apple ][.
> 
> Our Apples are better designed than "standard" PC's.  Real keyswitches,
> sculpted keys with good spacing, a minimal (or in the case of the GS,
> absent) space between the edge of the case and the front of the keyboard,
> a mouse small enough to actually hold, that doesn't try to conform your
> fingers to it...I think all of that, though it makes the Apple keyboards
> and mice look puny compared to the 104-key behemoths and gigantic mice in
> the PC world, probably does my hands and wrists far more good than all the
> split keyboards, gel-filled wrist-rests (how can people type with those
> damned things?) and other so-called "ergonomic" features put together.
> 
> It is only a theory at this point...But I have to wonder...typewriters
> have been around for ages, and so have word processors.  But most of us
> had never even heard of "carpal tunnel syndrome" (or thought it had
> something to do with clogged sewer pipes) before the rise of the
> PC...in fact, it really wasn't until the inexpensive PC clones, with their
> membrane keyboards arrived, that we started to hear about these RSI problems.
> 
> I just think it is interesting.  Anyone else have any thoughts?
>

     Your mention of the differences among keyboards reminds me a bit of 
differences among joysticks. Two of the things that stand out in comparing a 
good stick and a turkey are Physical Resistance and Feedback.

     A good stick forces you to 'work' against it. Centering Tension (the pull 
toward the center), handle size, and gripping position are designed to supply 
the right amount of opposition to your movements. A good stick also supplies 
reliable feedback-- tension increases as you push the stick farther from center.

     You can use a well-designed joystick-- the CT FlightStick is an example-- 
to battle space aliens for hours without fatigue. A stick with ultra-light 
tension or a mushy feel can produce cramping and fatigue in just minutes. (The 
classic Worst Design was an expensive magnetically-centered stick featuring a 
low centering tension which _dropped_ rapidly as you pushed away from center.)

     Your muscles work best when  1. there is something to work against  and  2. 
the work comes to a clear endpoint. When these conditions are missing, muscles 
must work against themselves. Examples of destructive results are problems 
experienced by tennis players and baseball pitchers. (Were baseball pitchers to 
wear some kind of arm-shoulder strap which would stop arm movement at the end of 
a throw, their careers would be greatly extended.)

     A well-deisgned keyboard will feature keys which smoothly oppose pressing 
with increasing resistance, have a moderate stroke length, and which have a 
clear break-through/stop endpoint. A good, sharp "break-though" event seems to 
be where most otherwise good keyboards fall short.

     The importance of Break-Through is best illustrated by looking at joystick 
'fire buttons'. Every arcade player knows that a correctly tensioned 'snap 
switch' makes for much better play than a mushy button you must squeeze 'until 
something happens' on the screen.

     Of course, there is more to RSI than fatigue induced by poor keyboards. For 
one thing, years of RSI-free experience with Apple II keyboards may relate to 
the differences between game playing, programming, etc. and typing. A skilled 
secretary may type-in more characters in a single day than many computer users 
produce in a month.

     The typical computer user normally engages in a variety of hand, wrist, and 
finger positionings with numerous, randomly-spaced pauses. When some vague 
feeling of stress or tiredness is felt, we automatically stop and rest-- lean 
back and stir a cup of coffee, page through a manual, etc.-- without much 
thinking about it. The business typist's movements are both faster and more 
limited-- i.e. the "R" in "RSI".    

     Another consideration is keyboard (mouse, etc.) placement. Many of us have 
tended to place our computers on whatever table or shelf was convenient. When 
there is a choice, Apple II users tend to aim for a setup which is also a 
comfortable game-playing environment. Such factors tend to favor a 'work 
area' several inches higher than the typist's with a good deal more space to 
'spead out'-- e.g. for game maps, programming manuals & printouts, ... . This 
setup automatically encourages wrist and fore arm support.

     Most game players probably find it difficult to believe that anyone could 
develop stress injuries from mouse use. Yet, watching some CAD and desktop 
publisher business users, it's easy to see how problems might develop-- How does 
anyone get into the habit of _not_ resting the wrist and fore arm when mousing?!

     Other mouse-related RSI factors probably relate to the mouse and choice of 
mousing surface. The stress-reducing benefits of having something to 'work 
against' will be lost on a slick, low-resistance surface. Similarly, we should 
expect that a very light mouse or one with no surface drag will produce fatigue. 
Another major mousing problem is poor buttoning. Mushy, often over-tensioned 
buttons are guaranteed to produce fatigue.

     You took a shot at the Microsoft Ergo Mouse's 'hand support' idea. I agree; 
the notion of using a mouse for hand support is silly. Your wrist and hand 
should, already, be well-supported on the work surface. Even so, I like the Ergo 
Mouse very much. On a good cloth-covered pad, its weight, shape, and drag make 
for very comfortable use. Button placement is close to perfect (for me) and the 
button switches have just the right tension, throw, and 'break-through' for 
low-fatigue clicking.

     Microsoft's Ergo Keyboard is kind of weird-looking. I've used one for a 
couple years and have decided that, for typing, the design is a significant 
improvement over flat, non-split keyboards. The key 'feel' is decent. Tensioning 
is good but presses lack the nice 'snap' (break-through) you get near the bottom 
of a keypress on some other high-quality keyboards.

     You mentioned size. Surprisingly, this is a factor which PC keyboard 
designers do not seem to have examined very thoroughly. Most users seem to like 
the idea of a big keyboard-- 'bigger is better' and more impressive-- so, maybe, 
efficiency is being sacrificed for marketability. Were the MS Ergo Keyboard to 
be shrunk to, say, 70% of its current size, it would, certainly, put more keys 
within easy reach which could reduce user stress.

     It makes sense that well-designed mice and keyboards can impact development 
of RSI. So can factors like positioning and size of the work area. Still, as 
your experience helps to demonstrate, how mice and keyboards are used is likely 
to be the main consideration. Basically, if we want to eliminate RSI, we are 
going to have to mix things up a bit when it comes to assigning tasks.     


Rubywand