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

The habit of using smartphones while walking has become widespread among modern individuals, particularly when pedestrians are in a hurry. However, there has been little exploration into the differences between standing and walking at various speeds in terms of smartphone use. In this study, we examined 60 young participants (30 men and 30 women) who engaged in smartphone tasks such as one-handed browsing or two-handed texting while standing, walking slowly, and walking normally. The measured variables included neck flexion (NF), head flexion (HF), gaze angle (GA), and viewing distance (VD). The study findings indicate that using smartphones while walking may cause a more pronounced kyphotic curve in the cervical spine compared to when standing, leading to increased strain in the neck region. The heightened neck load can be attributed to the concurrent dynamic nature of both walking and smartphone usage. Moreover, two-handed texting had a more detrimental impact on NF, HF, and GA when contrasted with one-handed browsing. The interplay among hand operation, posture, and maintaining arm position displayed an uncertain correlation with VD. While women typically exhibited smaller NF, HF, and GA than men, it is important to explore whether their shorter VD might contribute to increased eyestrain.