In the 1980s, there was "Pac Man wrist." In the 1990s, people developed "mouse shoulder." Later, there were reports of children developing "Nintendinitis" — cramps, numbness, pain or strains in the hands or wrists from playing video games.

The latest techno-pain could be "text message injury," a phrase coined by the British as the number of people in the U.K. complaining of sore thumbs from typing on cell phones and BlackBerries rapidly increased.

Americans might soon catch up. We sent approximately 130 billion text messages last year, double the number sent in 2005.

When new technology proliferates, repetitive stress injuries tend to follow. A new device may prompt people to frequently use a part of their body in new and unusual ways. Any frequent activity could potentially lead to soreness, numbness or pain in the overused body part. Overuse could also lead to chronic injury and pain.

We can overuse our digits and joints in many ways, and new devices can add to all that.

"With most overuse problems, it's an accumulation of what you do all day," said Stacey Doyon, president of the American Society of Hand Therapists. "We're being able to do more and more on small devices, and that's what's killing us. People are using them 24 hours a day. You get no break from it."

THUMBS ARE IMPORTANT

People underestimate the importance of the thumb.

"The thumbs are, by far and away, the most important digit on our hands," says Dr. Douglas Weikert, a hand surgeon and director of the hand center at Vanderbilt University Medical Center. "If I was going to build a hand from scratch, I'd start with a good thumb."

The thumb enables us to pinch and grab, actions that make many of the activities we take for granted possible. Weikert said that the base of the digit, where the thumb meets the hand, is also particularly prone to develop arthritis in part because we use it so much.

The newest use for our thumbs — entering information into tiny, digital devices — is relatively new but growing fast.

We've thundered away at buttons on joysticks and control pads with video games for the past 20 years. We punch e-mails into Blackberries exclusively with our thumbs. We may hit the screen of a Palm Pilot with our thumb instead of a stylus. We swivel through our music with our thumbs on increasingly small iPods.

Tweens and teens hardly talk on the phone, but they rapidly tap out text messages with their thumbs.

Text message injuries still are rare in the United States.

In other countries, where text messaging is more prevalent, there are already signs that all the thumbing hurts. A survey released by Virgin Mobile last year found that 38 percent of people in Britain suffer from sore wrists and thumbs from texting.

While messaging is growing exponentially in the U.S., Americans are still far behind other nations.

Americans who have wireless devices average about 50 text messages a month. According to a 2006 report in Business 2.0 magazine, people in Ireland average 100 text messages a month, while people in the Philippines send more than 200 text messages a month. The average Briton sends about 60 text messages a month.

That may be why few American physical therapists or physicians have actually seen cases of text message injury.

There still are no surveys or studies tracking possible text message injury in the United States.

Weikert says we may not see a significant increase in hand and thumb injuries for years because the technology is most popular with children and teens right now.