The way we type on a smartphone — jerking our thumbs in a side to side motion across the keyboard — is an unnatural way for the joint to move. Considering we now spend approximately five hours per day on mobile devices, it’s little wonder our hands are starting to show signs of wear and tear.
Essentially, “smartphone thumb” is a type of tendinitis — a condition that occurs when a tendon which joins muscle to bone becomes irritated and inflamed. It’s usually caused by a relatively low impact movement repeated consistently, and this specific type of tendinitis has only previously been seen in factory workers.
“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,” Dr. Kristin Zhao, a biomedical engineer at the Mayo Clinic in Rochester told CBS News. “Our hypothesis is that abnormal motion of bones in the thumb could be causing pain onset and eventual osteoarthritis.”
If you are one of the increasingly large number of people experiencing pain in your thumbs, it might be time to switch up your typing technique. Using a forefinger to text instead of your thumbs should help to avoid the strains of overuse.