Smartphone Addiction and Isometric Rotator Cuff Muscles Strength Among Adults

Background: Smartphones are essential in daily life, but excessive use may contribute to poor posture, affecting shoulder stability and rotator cuff muscle strength. Purpose: A cross section observational study was carried out to investigate how smartphone addiction affected the strength of rotator cuff muscles in adults. Methods: The study included 300 participants aged 18–30 (mean age 21.30 ± 2.75 years). Smartphone addiction was assessed using the Smartphone Addiction Scale-Short Version (SAS-SV), and rotator cuff muscle strength was measured using a hand-held dynamometer. Results: Spearman correlation analysis showed a weak negative non-significant correlation between SAS score and right Infraspinatus & Teres minor (r = -0.093, p = 0.107) and right Subscapularis (r = -0.097, p = 0.095), while a weak negative significant correlation was found with right Supraspinatus (r = -0.162, p = 0.005). For the left side, a weak negative significant correlation was observed with left Infraspinatus & Teres minor (r = -0.119, p = 0.039) and left Supraspinatus (r = -0.172, p = 0.003), whereas a weak negative non-significant correlation was noted with left Subscapularis (r = -0.094, p = 0.104). No significant difference was found in Infraspinatus & Teres minor and Supraspinatus strength between both sides (p > 0.05), but right Subscapularis showed a significant reduction in strength compared to the left side. Conclusion: There is a negative correlation between smartphone addiction and isometric rotator cuff muscles strength.