Carpel tunnel syndrome is a disorder affecting people who make repetitive movements. While many of the earlier, industrial age, causes like incessant hand-sewing, have been eliminated, the most common modern form is from typing. The repetitive movement compresses the median nerve in the wrist, causing pain in the hands, loss of hand strength, inability to sleep at night, and so on. Billions of dollars of worker's compensation claims are filed every year.
Some experts think that changing motions may make a considerable difference. Every ten minutes while typing, stop, flex your wrists, and flick your fingers upwards. They claim that this will prevent the syndrome. While others disagree, this has given me a tech idea.
Instead of a keyboard, we would have a tube, wide as a keyboard, and tall enough that a person's hands could be comfortably fit inside. Keys line the upper surface of the tube, and one can type by flicking your fingers upwards to the keys. (People with carpal tunnel from typing are most assuredly touch typists -- a hunt-and-peck typist could not make enough keystrokes in a day to injure themselves.) The device would come in USB and PS/2 styles, just like existing keyboards, and one would daily switch back and forth between the tube keyboard and the traditional kind.
Since the tube keyboard and traditional keyboard would require opposite finger-movements to type, this would allow people to type day after day with no repetitive injury.