Field Study of Postural Characteristics of Standing and Seated Smartphone Use

Abstract

Prior investigations have been primarily conducted in a laboratory to examine the effects of the smartphone use on the neck and head positions, whether these results are applicable to actual conditions is still unknown. This field survey thus analyzed the neck flexion (NF), head flexion (HF), gaze angle (GA), and viewing distance (VD) of smartphone users in public areas in Taipei, Taiwan. Six hundred smartphone users (300 men and 300 women) were photographed sagittally in standing, supported sitting, or unsupported sitting postures while using a smartphone. Results showed that women had significantly less NF and HF and shorter VDs than male users. Regardless of gender, higher NF was observed for standing than for sitting. Women had similar NF and HF while sitting supported and unsupported, but both were significantly lower than those while standing. By contrast, male users had higher NF and HF during unsupported sitting than during supported sitting. The NF (45°–50°) was much greater than the recommended maximum safe NF of 15°. Women may be at higher risk of visual strain because of shorter VD.

Text Neck Syndrome: A Growing Health Concern

“…At this position, the gravitational moment is considered the lowest and associated with the least complain of neck discomfort. 3,7 Forces on the neck increased linearly with the increment of the angle of neck flexion. It is doubled when the head tilts forward at 15° to roughly 27 pounds; reaching 40 pounds if the neck is flexed to 30°, 49 pounds at 45°, and angelinafebrina@gmail.com more than fivefold effect at 60 pounds at 60° (Figure ).…”

“…6 Another study collected data on neck flexion in college students during 8 hours of typical smartphone use using wearable motion sensors and discovered that they tended to spend more time with neck flexion exceeding 30° during smartphone use than during other activities. 7 In this current situation, mobile technology is within reach and people tend to spend more time on their smartphones or mobile devices and may end up with prolonged neck flexion causing text neck syndrome. This is a growing health concern and may influence mostly young generation.…”

User Walking Speed and Standing Posture Influence Head/Neck Flexion and Viewing Behavior While Using a Smartphone

“…These activities introduce different physical demands on users, with a notable focus on neck and head flexion (NF and HF, respectively). In particular, the changes in NF and HF that occur during smartphone use have undergone thorough investigation in the literature [3][4][5]. A larger NF is generally associated with heightened strain on the cervical spine [6], consequently escalating the risk of neck and shoulder injuries [7].…”

Holistic Approach for Markerless Head-Neck Posture Assessment

“…This means that the body points used to define the line that forms the angle are not necessarily the same. Most of the time the HTA is defined as the angle between the line through the tragus and canthus and the horizontal line through the tragus [17][18][19][20][21][22][23] (Figure 1(a)). But Mingels et al [24], for example, define HTA as the angle between the line through the tragus and canthus and the vertical line through the tragus (Figure 1(b)), Ormos et al [12] as the angle between the line of the tragus and the base of the nose and the horizontal line through the tragus (Figure 1(c)), and while Salahzadeh et al [25] define it as the angle between the line through the tragus and manubrium and the line through the tragus and chin(Figure1(d)).…”

“…Another angle that is often used to assess the head posture is the gaze angle. It is defined as the angle of the horizontal line through the canthus, and the viewing distance to the smartphone [21,25]. However, most of the studies, especially the cited studies, deal with analyzing a limited range of postures and specify a small number of possible angle measurements or analyses.…”