Scott Adams, the artist behind the comic Dilbert, has a movement disorder called focal dystonia that prevents him from drawing in the regular way. It, and his response to it, are discussed in an article in the Washington Post.
Focal dystonia, which can affect the hand (where it’s commonly called “writer’s cramp” when it affects writing), the neck (the most common site), eyelids or vocal chords, is something of a mystery. First reported in people who do fine finger work, including writers, seamstresses and musicians, it affects an estimated 29.5 individuals per 100,000 population [...] Often, focal hand dystonia patients are people who use the small muscles of the fingers and hands.
What I find most interesting about this condition is its neurological roots, as the fine finger work coupled with the stress that often triggers focal dystonia appears to “teach” part of the brain some broken connections:
“We think the disorder is largely associated with the basal ganglia,” which are deep brain structures that help regulate movement, Karp [Barbara Karp, deputy clinical director of the National Institute of Neurological Disorders and Stroke (NINDS)] said. One theory is that repetitive movements or some other cause somehow trigger abnormal learning patterns in the brain.
One therapy for focal dystonia is “sensory training,” changing techniques of practice so that the sensory areas of the brain can learn again how to give proper feedback to the motion parts. Adams, in his case, now uses a graphics tablet and draws Dilbert at many times the final size.
Link to Scott Adams, Drawing the Line in the Washington Post.