WII KNEE: Ouch - be careful, that's sore.Many people like to spend Christmas curled up on a couch in front of the fire with a box of Milk Tray, but in recent years, a growing number are having a seasonal burst of physical activity, as they perfect their golf swing and their tennis serve. No sitting around watching the TV for these poor unfortunates - they're up and running about for the entire season, and it's taking its toll on their health.

What's with all this exercise during the traditional time of lethargy?

The arrival of the Nintendo Wii has got folks up off their couches to participate in the virtual action - and has seen an increase in sports injuries directly related to the popular games console.

You're saying I hurt myself playing my Wii?

Looks like you've got a touch of Wii knee - a new ailment that afflicts users of the games console. Researchers at Leeds Teaching Hospitals have identified this new, er, strain of injury, and doctors have warned that an epidemic of Wii knee is set to break out as more families add the Wii to their array of home electronic devices.

But why does it hurt when I Wii? It's just a video game - the injuries are not supposed to be for real.

Because the Wii is a physical game, requiring the user to imitate the movements of a sportsperson, the danger of doing oneself an injury is greatly increased. People who are normally unused to getting up to change the channel are now having to jump wildly about the room like a virtual triathlete, and normally sedentary dads now have to make like Pete Sampras in order to keep up with their kids on the Wii scoreboard. Something's gotta give, such as the knee, elbow or lower back.

Well, now that I think of it, I did quite a bit of twisting and turning on the Wii balance board last night.

Doctors and osteopaths in the UK have warned against excessive use of the Wii in the first few days, especially if the user is unused to physical activity. The British Society for Surgery of the Hand noticed an increase in hand injuries last year due to careless use of the Wii, and predicted that this Christmas just past will see a huge increase in sprains, strains and broken fingers. One hand surgeon treated a patient whose finger had been fractured when her partner hit her hand with his remote control during a particularly enthusiastic game of tennis.

Sounds more like an epidemic of clumsiness.

The Wii was the most in-demand item for Christmas 2008, so this season not only brought a bonanza for the game dealers, it also promises a bumper season for physiotherapists, as waiting rooms begin to fill up with people suffering from RSI (remote-control strain injury).

Maybe we should go back to old-fashioned video games - at least you only got sore thumbs.

Alas, the Wii is here to stay, so the best advice is to make sure you are properly prepared for your Wii session. Do some stretches beforehand, and try to fit in some regular exercise in between Wii games. And for goodness sake, don't challenge gramps to a game of tennis right after Christmas dinner.

Try at home:"Dad wouldn't let us get a Wii, and then he put his back out playing Twister."

Try at work:"That's the 10th employee who injured himself taking down the Christmas tree - sounds suspicious."