Postural and Musculoskeletal Effects of Smartphone Use on the Neck and Upper Extremities in University Students

Background: Smartphone use is highly prevalent among university students and commonly involves sustained neck flexion and unsupported upper-limb postures, which may be associated with musculoskeletal symptoms of the neck and upper extremities. Objective: To estimate the prevalence of neck and upper-extremity symptoms among university smartphone users and to evaluate associations between symptoms and self-reported smartphone-use posture (neck posture, back support, and arm support). Methods: A cross-sectional survey was conducted in 2018 among 180 university students (18–30 years) who used smartphones for at least four hours daily and reported at least one year of smartphone exposure. A structured questionnaire assessed demographics, smartphone-use patterns, postures during use (neck flexed vs neutral; back supported vs unsupported; arm raised with vs without support), and symptom presence and characteristics. Associations were tested using chi-square analyses with effect sizes summarized as odds ratios. Results: Overall, 171/180 participants reported at least one neck or upper-extremity symptom (95.0%). Pain was the most common symptom (53.9%), and the neck was the most frequently affected region (47.2%). Symptom prevalence was higher in participants reporting flexed neck posture (144/144; 100.0%) than neutral posture (27/36; 75.0%) (p<0.001), and in those using unsupported raised-arm posture (122/123; 99.2%) than supported posture (49/57; 86.0%) (p<0.001). Unsupported back posture was also associated with higher symptom prevalence (97/99; 98.0%) than supported back posture (74/81; 91.4%) (p=0.043). Conclusion: Neck and upper-extremity symptoms were highly prevalent and were associated with forward-flexed neck posture and unsupported raised-arm posture during smartphone use.