Reaching For RSI
July 31st, 2005 | Published in RSI Stories | 1 Comment
In an article in The Union, a newspaper in Nevada County, CA, Dave Moller writes about workstation setup and computer ergonomics. The article discusses how best to arrange your workstation, and the importance of exercises and taking breaks. This is all pretty standard advice, and something you’ve probably heard a dozen times before, but a reminder now and then doesn’t hurt.
One thing that caught my attention was a short section on “reducing lever arm forces” by moving things such as “coffee cup, pens and telephone to within 10 inches of your body”.
I think this is actually pretty important. Well, not those items, at least not for me. But one of the things I did in the past that I believe caused me a lot of pain was when I had my mouse located far to the right of my keyboard. Since I was centered over the letter keys, every time I used the mouse, I had to reach way over and try to perform precise movements with my arm partly extended. This requires more muscular control than you might realize, and over time it fatigued the smaller muscles of the arm and hand, which caused me to rest my arm on the table or chair arm, which caused me to sort of lean to one side, which made my posture even worse than it normally is.
Currently I’m mousing with my left hand, which works out pretty well. The mouse is to the immediate left of my keyboard, and the keyboard and numpad is to the immediate right of the letter keys. This setup feels pretty well balanced. Of course, for a right-handed person, this means getting used to mousing with your left hand, and using a mouse that works left-handed. It took me a few weeks to acclimate to the new setup, but I think it’s better for me long-term.
August 8th, 2005 at 12:35 pm (#)
It is better to put items you use a lot closer to your body, I agree. But this will not affect the muscles of the hand and forearm (much). Biomechanics and knowledge of lever arms will tell you that extending the arm has the most effect on joints that are the farthest removed from the hand, so shoulder, neck and back. If you grab something now and then that is a bit of a reach, that will not be a problem. Might even be good for you to move a bit. If you need to do that very often, or if you need to hold a certain position with arms away from your body, it’s different. That creates static tension in your muscles, impeding blood flow, causing fatigue and in some (many?) cases RSI.
Holding your mouse for long periods of time (without even using it actively), especially when it is not close to your body, increases the chance to get RSI.