A spinal surgeon points out that sitting upright is a trap and advises reclining instead, while two other experts caution against immediately blaming screen use.
The website FastCompany published an article titled "Your smartphone is changing your body. Doctors say most people don’t know it’s happening," which can be interpreted in Thai as "Smartphones not only change behavior but may also be changing your body." It begins by noting that doctors and researchers have informally coined the term "Phone body" to describe physical changes caused by years of looking down, squinting, and scrolling on smartphones.
The most common condition encountered is called Tech neck. When people lower their heads to look at screens, the muscles at the back of the neck work to support the head. Initially, these muscles can handle the load, resulting in ordinary aches and pains. However, over time, the strain affects the spinal discs, which cannot compensate indefinitely. Prolonged stress may lead to premature cell death and accelerated degeneration.
Daniel Riew, a cervical spinal surgeon at Och Spine, New York-Presbyterian/Weill Cornell Medical Center, notes that he increasingly sees patients in their 20s, particularly due to smartphones' negative impact on posture, which people often neglect to address—unlike office desks where monitors can be raised.
From Riew's perspective, the solution is not to sit perfectly upright but to recline about 25-30 degrees with lumbar support and a headrest to distribute the weight of the head and torso onto the chair. He says this posture can be maintained for many hours without discomfort.
Regarding childhood myopia, Donald Mutti, a vision scientist, comments that screens likely do not directly increase myopia risk. Instead, the key factor is insufficient outdoor time, as screen use tends to keep children indoors more.
However, outdoor exposure for children also has conditions: they should spend about two hours outside daily, with at least 15-minute intervals under natural light of approximately 2,000 lux—roughly four times the light level in typical offices. This light intensity is easily found outdoors, even under tree shade.
The most sensitive aspect of the "Phone body" is handgrip strength, a general health indicator. Handgrip is essential for daily activities, and although it is declining in the general population, it is overly simplistic to blame this solely on frequent smartphone use.
Johannes Beller, a professor of medical sociology at Medical University Lausitz–Carl Thiem, states that a 2019 retrospective study found handgrip strength was already declining before smartphones became widespread.
Beller explains that these trends reflect lifestyle and occupational changes more than any single device’s fault. The most important factor is maintaining physical activity and strength for overall health.