CNN has reached out to Shahar and Sayers for comment.
In their research, Shahar and Sayers said young people may be developing tiny hornlike spikes at the back of their skulls, possibly caused by the shift in the weight of our heads from the spine to the muscles at the back of our head and neck. This anatomical feature is called an external occipital protuberance, or EOP.
The possible cause of this shift in weight? You probably guessed it. The researchers hypothesize that it is due to poor posture from people craning their heads forward more because of phone and mobile device usage.
For their first study, the two researchers set a threshold of 5 millimeters to record an EOP, and considered it an enlarged EOP if it exceeded 10 millimeters in length. They discovered that 41% of the participants, ages 18 to 30 years old, had an enlarged EOP in their skulls.
These types of bone spurs are more commonly found in the elderly, and are assumed to be a normal part of the aging process. However, Shahar and Sayers believe that the advance of technology has changed the timeline for this type of bone growth.
Their second paper studied a larger sample size of 1,200 X-rays for subjects 18 to 86 years old. Thirty-three percent of the subjects were found to have the bone growth, but oddly enough, the growth was found to have decreased with age.
“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,” Shahar told the BBC.
But not everybody agrees with the researchers’ ideas.
John Hawks, the Vilas-Borghesi distinguished achievement professor for the Department of Anthropology at the University of Wisconsin-Madison, said “this study doesn’t hold water.”
Hawks noted that the study lacked a results table that would have offered more detail about their findings, and there are contradictions between the text and charts in the study.
Hawks believes the data presented is not being consistently measured.
“There is no information about the duration or frequency of hand-held device usage in this study, so it is not possible to draw any correlation between the observations of enlarged EOPs and hand-held device usage,” Dr. Mariana Kersh, an assistant professor in the Department of Mechanical Science and Engineering at The University of Illinois at Urbana-Champaign and Director of the Tissue Biomechanics Laboratory, tells CNN. “There is definitely no cause and effect demonstrated in this study.
“The hypothesis regarding the role of hand-held device usage is only speculative and not based on any data presented in this study.”
The study lacks a control group, and the X-rays are taken of patients that had to visit a chiropractor with severe enough neck issues to have X-rays taken, which may not offer the best picture of the overall population.
Changing posture alone may also not be enough to spur such a significant bone adaptation.
“Bone adaptation usually occurs in response to dynamic repetitive movements that the body is not accustomed to seeing,” Kersh said. “The strain on the bone must also be of sufficient magnitude (higher than usual) to induce adaptation. With what we know about how bone responds to mechanical loading, changing posture alone would likely not result in bone changes, especially within a single lifetime.
“Inducing bone adaptation through musculoskeletal loading is possible, but requires increased, repetitive, atypical loading which are different from the hypothetical loads suggested by Shahar and Sayer.”