Repetitive strain injury (was: ThinkPad Pointers)

[Bill McGonigle]

On Jan 17, 2008, at 07:21, Ben Scott wrote:

>   But not for eight hours a day five days a week.

A professional playing a piano bar could be expected to work a 4- 
midnight shift, but they take breaks (see they've worked that out too  
already)!  Odd, isn't it, that we expect musicians to take breaks,  
but a transcriptionist who takes a half hour break every 90 minutes  
would be a 'slacker'. (Back to your cube!)  That's not to say  
musicians can't get RSI - many do, but they largely ignore the  
standard advice, "if it hurts that's your body's way of telling you  
you're doing something wrong."  Lord knows I've gotten there on 18- 
hour code-a-thons.

>   Besides, "we've
> always done it that way" isn't a very good reason for doing anything.

In and of itself, that's correct.  But we ought not be too hasty in  
tossing out all of our time-tested techniques because they're old,  
especially when they work.

>   As I understand it, convention wisdom is that you want neither.  You
> want neutral.  With wrists *down*, you tend to be bending yours hands
> up at the wrist joints.  Support the wrist and/or heel of the hand, so
> you're neither bending a lot, nor trying to hold your hands suspended
> in mid-air.  Proper posture is the most important thing, and next to
> that, simple wrist support (which might just involve moving your
> keyboard).

It may be that I've never seen a decent wrist support, but all the  
ones I have seen still lead to a positive (on the vertical axis)  
deflection of the hand from the wrist.  I'm arguing for a straight  
path, from arm muscles to fingers, for the tendons to take, which is  
what the 'wrists up' position does.  I see I never specified that,  
which may have lead to the impression of a negative deflection for  
those unacquainted.  To try to explain better:

* Sit up straight.
* Let your upper arms hang naturally.
* Put your hands out in front of you, at the minimal-resistance point  
of deflection from the sagittal-axis of your body, fingers hanging  
neutrally, with the line from the inside of your elbow to the tops of  
your knuckles parallel with the floor. (boy, we have lots of degrees  
of freedom)  Your wrists will be at the same deflection as if you  
were standing with your arms hanging freely.
* Hold your hands over the keyboard
* Type/Play

Obviously proper keyboard and chair height are essential.  Also, as  
every six year old piano student knows, it takes about a week for  
your large muscles to be strong enough to support the arms' weight  
for any length of time, for most values of suburbanites.  I suspect  
farm kids don't see this problem.

-Bill

-----
Bill McGonigle, Owner           Work: 603.448.4440
BFC Computing, LLC              Home: 603.448.1668
bill at bfccomputing.com           Cell: 603.252.2606
http://www.bfccomputing.com/    Page: 603.442.1833
Blog: http://blog.bfccomputing.com/
VCard: http://bfccomputing.com/vcard/bill.vcf