My posture is so appalling whileI sit for hours at this computer that I'm surprised I don't suffer from deep-vein thrombosis, never mind carpal tunnel syndrome. I've certainly got off lightly compared to friends and colleagues who, despite having orthopaedic chairs, wrist supports, footrests, and posture the envy of a concert pianist, still get shooting pains in their arms whenever they press Ctrl Alt Delete. Modern computers, with their almost brutal efficiency, don't give us the regular, convenient breaks that the old-style office environment did.

Two things have remained unchanged throughout the rise of the computer workstation: the keyboard and the mouse. Mice may tart themselves up as trackballs and the like, but they essentially still do the same thing – remotely control a pointer on a screen which we position over things and click. But with the popularity of touchscreen smartphones and the advent of tablet computers such as the iPad, suddenly the mouse looks like a slightly laughable piece of equipment for controlling a computer – a bit like using chopsticks to peel a banana. Why fiddle about when you can just get in there with your fingers and do it directly?

But there's a good reason why touchscreen displays won't spell the end of the remote pointer, and it's down to a physical reaction that makes carpal tunnel look like a mild case of pins and needles.

"Gorilla arm" is a condition that was spotted almost as soon as light pens were invented as a means of interacting directly with screens. The pens received some hype in the mid-Eighties as a fabulous new input method, but anyone involved in ergonomics was quietly murmuring: "No, no, you forgot about gorilla arm."

As any sadistic PE teacher will tell you, extending ones arm horizontally for long periods can be painful, and while it's a perfect punishment for people who have chosen to hide in bushes rather than participate in a cross-country run, it's not something you want in an office environment. The arm starts to feel strangely swollen – hence the term "gorilla".

Apple announced last week that its laptop and desktop machines would never feature touchscreens. Instead, it is concentrating on desk-mounted trackpads to achieve those multi-touch effects – scrolling, zooming and rotating. Toshiba and Hewlett Packard have flown in the face of human frailty by manufacturing desk-mounted touchscreens – and sure enough, at least one reviewer immediately noted that their arm felt a bit funny after using them.

So, whatever the film Minority Report may have excitingly predicted, the vertical, desk-based screen will be something we stare at, and the horizontal desk surface will be something we interact with. Until, that is, inspiration deserts us and the desk becomes something we stare at, and the screen something we do our best to ignore.

* Children with a flair for unravelling computer code and who fancy some excessive treats this Christmas could do worse than follow the example of 12-year-old Alex Miller, a San Jose resident who has just become the latest beneficiary of Mozilla's "bug bounty" program.

Individuals discovering a critical security hole in the Firefox web browser receive a cheque for $3,000 (£1,900) and, curiously, a Mozilla T-shirt. Miller estimates that he spent about 15 hours looking for it – a neat $200 hourly rate. Few companies offer such bounties. Google raised its bonus for discovering bugs in the Chrome browser to £3,133.70 this summer, but many adopt the "if it hasn't gone wrong yet, it doesn't matter" approach. Others have even fired employees who have dared to point out vulnerabilities in software.

Miller (don't you just love him) also plays the guitar, is learning Mandarin Chinese, and donated the first $100 of his earnings to a kitten rescue charity. Perhaps here we have the new Mark Zuckerberg, except slightly better-adjusted.