Only in Britain would a national health body formally assist in the prevention of Wii injuries. The British Chiropractic Association has "developed a 'Wii Warm Up' to help users retain nimble fingers but avoid over exertion".

Tips include the "Shoulder Shrug":

Slowly shrug your shoulders towards your ears. Hold for 2/3 seconds, and then relax. Repeat 3 times. Because it is easier to relax a muscle after you've tightened it, you will relax the muscles in the shoulder and allow the blood to flow into the arms.

And my personal favourite, the "Neck Muscle Stretch":

Try to make a double chin, to stretch the muscles at the base of the neck. Hold this position for 2 to 3 seconds and repeat 3 times. Always stretch very slowly.

Try to make a double chin? If you're relying on the Wii for exercise, you're probably on at least a triple. Luke Plunkett

The Wii Warm Up [BCA, via metrowii]