Smartphone use is a risk factor for both neck and shoulder musculoskeletal disorders. The objective of this study was to evaluate an ergonomic arm support prototype device, which may help improve posture while using a smartphone, by determining its effect on muscle activity, muscle fatigue, and neck and shoulder discomfort. Twenty-four healthy young adult smartphone users performed 20 min of smartphone game playing under two different conditions, smartphone use with support prototype device (i.e. intervention condition) and without (i.e. control condition), while neck and shoulder posture were controlled at 0° neck flexion and 30° shoulder flexion. Activity and fatigue of four muscles were measured using surface electromyography (sEMG), these were: anterior deltoid (AD), cervical erector spinae (CES), upper trapezius (UT) and lower trapezius (LT). The intervention condition showed significantly decreased activity of all muscles. Fatigue of all muscles, except LT, significantly increased over time compared to the start point in the control condition. There was no significant difference in muscle fatigue between each time point in the intervention condition. In conclusion, the ergonomic arm support prototype device can be used as ergonomic intervention to reduce neck and shoulder muscle loading and fatigue.

使用智能手机是颈部和肩部肌肉骨骼疾病的危险因素。这项研究的目的是评估一种符合人体工程学的手臂支撑原型设备，通过确定其对肌肉活动、肌肉疲劳以及颈部和肩部不适的影响，它可能有助于改善使用智能手机时的姿势。24 名健康的年轻成年智能手机用户在两种不同条件下进行了 20 分钟的智能手机游戏，智能手机使用支持原型设备（即干预条件）和不使用（即控制条件），而颈部和肩部姿势控制在 0°颈部屈曲和 30° 肩关节屈曲。使用表面肌电图 (sEMG) 测量四块肌肉的活动和疲劳，它们是：前三角肌 (AD)、颈竖脊肌 (CES)、上斜方肌 (UT) 和下斜方肌 (LT)。干预条件显示所有肌肉的活动显着减少。与对照条件下的起始点相比，除 LT 之外的所有肌肉的疲劳随着时间的推移显着增加。在干预条件下，每个时间点之间的肌肉疲劳没有显着差异。总之，符合人体工程学的手臂支撑原型装置可用作人体工程学干预，以减少颈部和肩部肌肉负荷和疲劳。