Impact of Screen Time and Cervical Biomechanics on Neck Disability Index among Healthcare Students: A Cross-Sectional Study with Biomechanical Validation

Background: Nowadays, smartphones and digital screens have become a regular part of study life for nursing, physiotherapy, and allied health students. Reading PDF notes and watching lectures on mobile phones for long hours often makes students bend their necks forward without noticing it. Although this problem is commonly called text neck syndrome, it is still unclear whether neck disability comes mainly from total daily screen hours or from the actual physical load placed on the neck due to faulty sitting postures.  Objectives: This study aimed to find the prevalence of self-reported neck disability among healthcare students in Kuppam, measure their daily screen time from smartphone tracking logs, calculate their physical neck tension in natural study postures, and find a safe diagnostic cut-off value for cervical spine loading.