In the current Dilbert newsletter, Scott Adams describes an affliction that's affecting his drawing skills. Here's what he writes:
"Alert readers have noticed that Dilbert looks different lately, almost as if someone else is drawing it. Well, it's still me, but here's what's happening: I lost the use of my right hand for drawing, thanks to overuse. Technically, it's called a focal dystonia. It's essentially a brain-mapping problem caused by overusing the hand. The hand is structurally healthy and perfectly fine for every possible use EXCEPT drawing. It's very specific. My brain essentially removed from me the ability to do the thing that was hurting it.
One way I can confirm that it's a brain issue is that when I try to draw with my LEFT hand, my RIGHT hand spasms immediately. Some part of my brain doesn't want me drawing because that's what caused all the discomfort.
For a few weeks I worked left-handed. I'm not quite ambidextrous, but if I work slowly, it looks about the same. Some of the lefty ones have a "L.H." on them to tip you off.
Left-hand drawing was too slow, so I looked for, and found, a technical solution. Wacom has a product that allows you to draw directly onto a special flat computer screen that tilts and turns just like paper on a drawing board. It's called the Cintiq 21UX, and I've been using it for the past several weeks, with much success. It will take a while for my characters to look the same as old, but I'm closing in on it.
The reason I can draw on the computer, but not on paper, is because now I work at a different scale (larger), and the feel of the stylus on the screen is so different from pen-on-paper that my brain doesn't think I'm drawing, so it doesn't trigger the hand spasms.