James Cullen was already spending long periods sitting at his work PC when he was given a BlackBerry last year. Soon the 59-year-old investment banker found himself answering e-mails on the handheld device out of hours, too. After a few months, he started experiencing a debilitating stiffness and pain in the thumb and fingers of his right hand.

“Now, it’s difficult to close my hand, or pick up a kettle,” he says, “and shaking hands can be very painful.”

Cullen blames a modern malady: “BlackBerry thumb”. This is a colloquialism for a form of repetitive strain injury (RSI) linked not just to over-use of a BlackBerry, but of other handheld devices, including mobile phones.

Indeed, earlier this year it was reported that an Italian girl needed treatment after she’d developed a 100-a-day text habit, while a 13-year-old girl developed “texting” tendonitis, according to the Medical Journal of Australia, after sending nearly ten messages a day for a month.

The American Society of Hand Therapists recently warned consumers that handheld electronic devices are linked to a rising incidence of carpal tunnel syndrome and tendinitis. The problem is compounded, it was suggested last week by the Manchester Area RSI Support and Action Group, because doctors sometimes fail to pick up on the signs.

A typical symptom of this high-tech “abuse” is an aching, stiff thumb, but hand and arm pain can also feature. According to Kevin Fleisch, head of the London Area RSI support group, it is a combination of pressure from work and the addictiveness of these gadgets that we should blame. “People need to realise that prolonged use carries a danger.”

Carsten Uth, a physiotherapist with a special interest in ergonomics, explains that while the exact causes of “BlackBerry thumb” are not clear, the thumb tendons can become swollen and painful through overuse. The pain may also be caused, say experts, by premature onset osteoarthritis, brought on by the strain put on the thumb joint.

“We also think that nerve damage in the thumb and wrist occurs in some cases,” Uth says. “People tend to sit slumped, with their neck stuck out and looking down at these small screens. That can cause compression of the nerves that run from the neck, down the arm and into the hand, making nerve damage more likely. Posture is at the heart of so many RSIs, and it’s impossible to maintain good posture when using these gadgets.”

Depending on the underlying cause, treatment can include manipulation of the vertebrae in the neck, arm and hand stretches, and cortisone injections to dampen inflammation of the thumb tendons. With treatment and rest, recovery from the pain of using a handheld device is usually within six to eight weeks, but it can take up to six months, or even longer.

Research In Motion, which makes the BlackBerry, says that the company considers ergonomic factors when designing its keyboards. “Any product can be overused so people should listen to their bodies and adjust their routine if necessary.”

But what can you do to help your hand? Holding the BlackBerry at head height, to sit up straight and look forward, is not the answer, says Uth, because that carries a risk of shoulder injury. But users can make sure their posture in daily life is good. Ultimately, it’s good time management that might save you from condition.

“Be disciplined: if it’s possible to answer that evening e-mail tomorrow at your work PC do so,” Uth says.

www.londonrsisupportgroup.org.uk

Some of the names have been changed

Don’t be a BlackBerry fool