SINGAPORE - Are you reading this on your smartphone? This new study should make you sit up.
Tilting your head over a game of Candy Crush, a frequent sight on trains here, can put up to 60 pounds (27kg) of weight on your neck, according to the study in Surgical Technology International.
The incremental stress experienced can lead to "early wear, tear, degeneration, and possibly surgeries", the report said.
"People spend an average of two to four hours a day with their heads tilted over reading and texting on their smartphones and devices," said Dr Kenneth Hansraj, Chief of spine surgery at New York Spine Surgery & Rehabilitation Medicine in the study.
"Cumulatively this is 700 to 1400 hours a year of excess stress on the spine."
By using simulations in a design engineering software, Dr Hansraj modelled the amount of stress a person's spine is subject to when they tilt their heads forward 15 to 60 degrees.
"An adult head weighs 10 to 12 pounds in the neutral position. As the head tilts forward the forces seen by the neck surges to 27 pounds at 15 degrees, 40 pounds at 30 degrees, 49 pounds at 45 degrees and 60 pounds at 60 degrees," the study said.
Dr Hansraj advises that individuals should make an effort to look at their phones with a neutral spine and avoid spending hours each day hunched over.
Maintaining a neutral spine - with ears aligned with the shoulders and shoulders open - not only reduces wear and tear on the spine, it has been associated with a decrease in cortisol, a hormone produced in response to stress.