Estimation of Forearm, Deltoid, and Trapezius Muscle Activities Due to Overuse of Smartphone with and Without Armrest

Abstract

Recent boom of smartphone technology and attractive new features with affordable price are continuously convincing new users to upgrade their phone and eventually they spend far more screen-time than ever before. Recent studies have shown that deltoid, trapezius, and forearm muscles mostly get affected among other muscular regions. But previous studies have some research gap in measuring combined effect of these three muscles due to smartphone use and they did not consider armrest conditions while measuring the combined muscular effect. Eight participants were recruited and EMG of six muscles (Upper Trapezius (UT), Anterior Deltoid (AD), Abductor Pollicis Longus (APL), Flexor Carpi Ulnaris (FCU), Extensor Pollicis Longus (EPL), and Abductor Pollicis Brevis (APB)) was recorded. Results found difference of UT MVC% when using cellphone on the chair with or without armrest. Gender had influence on part of muscles activity.