Effect of different smartphone uses on posture while seating and standing

In this study, we investigated possible alterations of neck and trunk posture when using smartphones. Fifteen healthy young subjects were asked to perform four activities with the smartphone (gaming, messaging, web surfing, video watching) in two different postures (stand and seat). Kinematics of both neck and trunk was recorded by an optoelectronic system, and the neck, trunk and cranio-cervical angles were extracted to evaluate the variations with respect to the baseline condition. The results showed statistical differences for neck and trunk angles between the two postures for all the activities with an increase of the values in the seated position. No significant differences were found among the activities except for neck angle in both standing and sitting postures. The results highlight that the significant alteration of the neck and trunk posture shows up when the activities are performed in the seated position. Furthermore, the variation of the neck angle depends on the performed activity; in fact, during gaming the flexion-extension of the neck is greater than during video watching. These results suggest that during smartphone use the posture undergoes some changes that may be a potential risk factor to develop neck pain, musculoskeletal fatigue and disorders.