Take your hand and feel the back of your head, just where your spine joins the bottom of your skull. If you can feel a thin growth, a bit like a small boney tail, it could be a sign your body is responding to 21st-century living and smartphones. 

A study published in the journal Scientific Reports in 2018 argued that heavy use of smartphones and handheld devices might explain why an increasing number of young people have an unusual boney spur on the back of their skulls.

Scientists from the University of The Sunshine Coast in Australia noted that a growing number of young people have a boney growth sticking out of the back of their skull. Typically, the growths were 2.6 centimeters long (1 inch), but they were seen to grow up to 3.1 centimeters (1.2 inches) in length.

Known as an enthesophytes or enlarged external occipital protuberance (EEOP), the bony projections arise from the sites where ligament or tendon attaches to a bone. Since they typically grow over a long period of time, they expected to find they were more common in aging populations. However, they found the exact opposite. In a study of 1,200 people, aged from 18 to 86, the enlarged spikes occurred in 33 percent of the participants, but most commonly in males ages 18 to 30 years old. In fact, every decade increase in age resulted in a 1.03 reduction in the likelihood of having the growth.

Previous studies also suggest that this is a relatively new phenomenon, as it wasn’t seen in young adults during the 1990s, at least not to the same extent.

"I have been a clinician for 20 years, and only in the last decade, increasingly, I have been discovering that my patients have this growth on the skull," lead author David Shahar, a health scientist at the University of The Sunshine Coast in Australia, recently told the BBC Future.

The research didn’t look for a clear cause-and-effect relationship; however, the fact it’s such a recent phenomenon among young adults started to get the researchers thinking. Drawing on other studies that have suggested smartphone use is associated with bad postures, they suggested that smartphones and “text neck” could be to blame. Spending hours each day with your neck crooked downwards, endlessly flicking through the same three apps over and over again, applies new stresses to the base of the skull, to which the body responds by laying down new bone. The result, they hypothesize, is this strange boney spur.

“The development of EEOP may be attributed to, and explained by, the extensive use of screen-based activities by individuals of all ages, including children, and the associated poor posture,” the study authors conclude.

“We hypothesize that the use of modern technologies and hand-held devices, may be primarily responsible for these postures and subsequent development of adaptive robust cranial features in our sample.”

Update 21/06/2019: We should stress that this is fairly speculative and there are a range of other factors to consider. For example, as The New York Times highlighted, much of their data came from people visiting a chiropractic clinic and required X-rays. Therefore, it’s safe to say, these subjects might not be representative of the whole population.

[H/T: BBC Future]