Extent and Association of Smartphone Usage With Musculoskeletal Outcomes Among Medical Students: A Comparative Cross-Sectional Study

Introduction As gadgets become a part of human life, smartphone (SP) use involves repetitive hand and digit movements that may contribute to musculoskeletal strain, especially in the thumb, neck muscles, back muscles, and upper limb joints. Adoption of non-neutral postures during SP use may also contribute to musculoskeletal disorders. In the contemporary scenario, the present study aimed to assess the association between SP usage and musculoskeletal outcomes among medical students. Methods The phase II MBBS students were stratified into low (score of ≤30) and high (score of ≥30) users based on their response to the SAS-SV (Smartphone Addiction Scale-Short Version). The objectives were: (i) comparing forward head protrusion (FHP), measured using the craniovertebral angle (CVA); (ii) documenting the region of maximum pain among the neck, hands, and joints of both upper limbs using the visual analogue scale (VAS); and (iii) assessing the cross-sectional area (CSA) and circumference of the median nerve (MN) within the carpal tunnel, as well as the CSA of the flexor pollicis longus (FPL) tendon, measured at the mid-thenar level using ultrasonography. Results The CVAs of the low and high users were 45.89 ± 5.8 and 45.24 ± 4.8, respectively. The lower the CVA, the higher the FHP. The prevalence of neck pain was statistically higher among high users (p < 0.05). Pain was reported more frequently among high users in the shoulder and thenar regions, but this was not statistically significant. The circumference (1.10 ± 0.15), CSA (0.09 ± 0.16) of the MN, and thickness of the FPL (0.14 ± 0.27) were increased in high users in their dominant (right) hand compared to low users (1.08 ± 0.14, 0.06 ± 0.01, and 0.11 ± 0.19, respectively). Conclusion The study documents a possible association between increased SP use and musculoskeletal discomfort, particularly in the neck, but objective structural changes were not evident. The findings were not statistically significant, which may partly be due to methodological limitations. The planning and development of more specific preventive measures, which are critical for reducing SP-associated repetitive strain injuries, would benefit from future studies incorporating larger samples, dynamic assessments, and better control of confounding factors to clarify these relationships.