The condition formally known as tendinitis was earlier only seen in factory workers. It causes the tendon that bends and flexes the thumb to become inflamed.
More and more people are complaining about this type of pain in their thumb each year, according to doctors.
"One of the hypotheses is that the joints get loose and lax, and because of that, the bones kind of move differently than they would in a normal situation," said Kristin Zhao, from the Mayo Clinic in the US.
Zhao said the movements we require our thumbs to make as we hold our phones are awkward.
More From This Section
"It's also a movement that requires some force through the thumbs. It's not just free movement in space," she said.
Researchers began using a dynamic imaging technique in 2010 to watch the bones of a healthy patient move so they could document what is normal and compare it with what is not.
"Our hypothesis is that abnormal motion of bones in the thumb could be causing pain onset and eventual osteoarthritis," Zhao was quoted as saying by the 'CBS Minnesota'.
To prevent problems, start by giving your thumbs a break, doctors said. Mix up your method by using your forefinger or use your voice to dictate a message.
Perform daily stretching exercises with wrists and fingers may also help prevent the condition, they said.