Scott Adams, the author of Dilbert has a condition called focal dystonia, which I'm going to define as a breakdown in the network between your brain and your hands: you tell your hand to draw a straight line and it starts drawing a squiggly line. According to Scott Adams, Drawing the Line, Adams had to change how he draws the strip and adapt to a new drawing tool because of the impact on his work.

Often, focal hand dystonia patients are people who use the small muscles of the fingers and hands.

Adams switched to a new tool, a Wacom Cintiq graphics tablet, to draw Dilbert:

Since January, Adams has been sketching and drawing "Dilbert" using an interactive display developed largely for graphic artists. Produced by Wacom Technology, based in Vancouver, Wash., the Cintiq 21UX LCD tablet allows artists to use a stylus on a pressure-sensitive computerized tablet. For Adams, this means he doesn't have to push down hard to draw. In addition, the software requires him to draw on an enlarged scale. Together, these effects keep his brain from prompting his hand to freeze up, he said.

Via: Mindhacks.