Re: High-tech loses headband

Patrick Wilken (
Sat, 14 Aug 1999 11:06:00 +1000

>Due to carpal tunnel syndrome, I have to rest my hands for a week or
>two. I probably won't even be checking my email, since the doc says
>complete rest is very important.


I am not sure if this is of any particular direct relevance to you, but I thought you might be interested.

best, patrick


Research published in this week's (10 April) edition of New Scientist has shed light on the cause of the most elusive type of repetitive strain injury (RSI). The early findings have already led to alternative treatments radically different from established practice, that could potentially help tens of thousands of sufferers to make a recovery. The new evidence could also lead to better ways of preventing the affliction in the future.

RSI covers a whole category of injuries that result not from a single incident but from sustaining a particular activity over a long period of time. In some forms -- such as carpal tunnel syndrome which causes chronic pain and irritation in the wrist -- problems are due to physical damage that can be observed and treated with surgery, but other forms have proven more puzzling. Keyboard users complaining of unfocussed pain or a general lack of dexterity in their hands or forearms have baffled doctors by displaying no signs of physical damage. These forms of RSI are labelled overuse syndrome and patients are advised simply to rest in the hope that their symptoms will disappear.

Researchers in the US and Germany have discovered that rest may be useless for these particular sufferers. Experiments have shown that long periods spent making rapid, repetitive hand movements can lead to harmful changes within the brain, rather than in the hand. Change in itself is normal, because the parts of the brain used to monitor sensation and control movement are continually being honed by experience. However, the researchers postulate that some rapid hand movements are effectively 'fooling' the brain into making the wrong kind of adjustments to its map of the body.

It seems that the small, rapid movements used in typing and operating a mouse can be mistakenly processed by the brain as though different muscles were operating simultaneously, rather than in rapid succession. If the brain makes this mistake, its mental map of the hand can become inaccurate. Eventually the brain will lose its ability to distinguish between, say, muscles on the back and the front of the fingers. Once the degradation is in place, it becomes impossible or painful to use the fingers properly as the brain mistakenly tells muscles to pull in opposite directions at once.

Rest cannot correct the problem, because inactivity does nothing to mend the mental map. By contrast, researchers realised that slow exercises designed to force the brain to make fine distinctions might be restorative. So while resting is pointless learning Braille, for example, might do the trick.

The researchers have observed the brain changes in primates made to work switches for their food, and in musicians suffering from a repetitive stress condition known as focal dystonia. New Scientist reports that the brain-maps of the musicians were shown to improve after re-training. No-one has yet studied the brains of computer users suffering from overuse syndrome, but a small group of such patients who underwent the new treatment were all able to return to work within three months.

One unanswered question is why the majority of keyboard users don't develop this kind of RSI. According to the published report, it may only be those people with a generally poor ability to spread their fingers that are at risk.

Patrick Wilken
Editor:        PSYCHE: An International Journal of Research on Consciousness
Board Member:      The Association for the Scientific Study of Consciousness