Cell phones seem to be one of the many boogeymen of modern society; they can be blamed for almost everything. Exasperated adults often lament how frequently people, especially young children, check their devices. So when a news story interrupted my hotel breakfast with the headline, “Cell phones linked to horns in children,” it almost wasn’t surprising. Almost. Never mind the misleading thoughts the headline prompts (I know I wasn’t the only person thinking of devil’s horns). Try to approach this story with an unbiased curiosity. If you haven’t already seen the original research article, please check it out before reading further. Link here: https://www.nature.com/articles/s41598-018-21625-1 [1]
What’s the verdict? Does the study support the ideas of cell phones causing horn development via an enlarged external occipital protuberance (EEOP)? Probably not. Each of the authors’ claims in the discussion section makes sense individually. Increased stress at transitional zones of bone and ligament can cause connective tissue proliferation, sometimes in the form of bone spurs. [2] High frequency of forward head protraction could theoretically explain how one-third of the study population has EEOPs. But the data of the study simply do not support phones and other devices causing this phenomenon. Below the sensational x-ray images of prominent EEOPs are several graphs. Figure 3 shows that all ages have comparable amounts of forward head protraction, except for the oldest (60+) age group. Figure 4 places the highest prevalence of EEOP in the youngest (18-29) and oldest age groups. The authors claim that EEOP rates in the 18-29 age category are statistically significant and that “EEOP was unlikely to occur across any of the other age categories.” The word “unlikely” is dangerously subjective. Given that the lowest EEOP percentages were around 10% for people in their fourth through sixth decade, one could easily argue that it is simply not a correct interpretation of figure 4.
In the methods section, which is oddly placed after the sensational claims of the discussion section, it is clear that this was a descriptive study with no intentional control. All x-ray images were obtained from a mix of symptomatic and asymptomatic patients presenting to one chiropractic clinic. Considering the ubiquity of handheld devices, it would be difficult to run a study of young adult EEOP size with the control being individuals without significant device use. Even so, this study is not controlled for the time period of the imaging, only including x-rays taken after the advent of widespread cell phone use.
The authors gloss over important facts to drive their point home. Logistic regression showed a statistically significant relationship between age, sex, and forward head protraction; however, earlier in the paper they mention that males are 5.48 times more likely to have EEOP than females. They argue that differences in mobile device habits between males (more movies and gaming) and females (continuously checking social apps) could explain this, but bone spur formation is already known to be more prevalent in males. [3]
Let’s return to the root argument of the study: an otherwise unexplained increase in EEOP frequency in the 18-29 age group could be explained by frequently looking down at devices such as cell phones. Few studies have explored the musculoskeletal implications of mobile devices, and the evidence for neck flexion causing pathology is limited and inconclusive. [4] Briefly glancing at the study’s data and arguments could lead you to believe the authors. The theory behind increased neck flexion causing EEOP formation is plausible, but the study does not demonstrate a clear connection to cell phone use. There are simply too many other possible factors for EEOPs in young people, such as school-work or reading. All these arguments ignore the fact that small EEOPs are subclinical and insignificant. Even so, the article was convincing enough to spark viral news stories giving mothers more reason to tell children to put their phones away.
Horns in the back of our heads can probably be added to the list of cell phone myths. We also know that cell phones do not significantly affect brain function [5], cause cancer [6], or cause depression (assuming healthy social network use). [7] In fact, cell phones have the potential to improve the delivery and treatment of mental disorders through specialized apps and increased patient-provider contact. So what headline should the cable news organizations have run if they wanted to demonize cell phones? Cell phone use while driving continues to be the biggest danger of cell phones by far. Kudos to Arizona for becoming the 48th state to pass a texting while driving ban. [8] Better late than never.
- Shahar D, Sayers MGL. Prominent exostosis projecting from the occipital squama more substantial and prevalent in young adult than older age groups. Sci Rep. 2018 Feb 20;8(1):3354. doi: 10.1038/s41598-018-21625-1.
- Benjamin M, Toumi H, Ralphs JR, Bydder G, Best TM, Milz S. Where tendons and ligaments meet bone: attachment sites (‘entheses’) in relation to exercise and/or mechanical load. J Anat. 2006 Apr;208(4):471-90.
- Rogers J, Shepstone L, Dieppe P. Bone formers: osteophyte and enthesophyte formation are positively associated. Ann Rheum Dis. 1997 Feb;56(2):85-90.
- Xie Y, Szeto G, Dai J. Prevalence and risk factors associated with musculoskeletal complaints among users of mobile handheld devices: A systematic review. Appl Ergon. 2017 Mar;59(Pt A):132-142. doi: 10.1016/j.apergo.2016.08.020.
- Zhang J, Sumich A, Wang GY. Acute effects of radiofrequency electromagnetic field emitted by mobile phone on brain function. Bioelectromagnetics. 2017 Jul;38(5):329-338. doi: 10.1002/bem.22052.
- National Cancer Institute. Cell Phones and Cancer Risk. National Institutes of Health. Accessed 2019 July 2 from: https://www.cancer.gov/about-cancer/causes-prevention/risk/radiation/cell-phones-fact-sheet.
- De-Sola Gutiérrez J, Rodríguez de Fonseca F, Rubio G. Cell-Phone Addiction: A Review. Frontiers in Psychiatry. 2016 Oct 24; 7: 175.
- Fifield J. Arizona Ban on Cell Phone Use While Driving: What to Know About the Law. AZCentral. Published 2019 Apr 8. Available from: https://www.azcentral.com/story/news/politics/arizona/2019/04/08/arizona-ban-cellphone-texting-while-driving/3405522002/.
Luke Wohlford is a medical student in the University of Arizona College of Medicine - Phoenix, Class of 2022. He graduated from the University of Arizona in 2018 with a Bachelor of Science in physiology. Luke plans to go into emergency medicine has special interests in public health and EMS. He spends most of his free time hanging out with his dogs Kanye and Kelso or feeling guilty about not exercising.