The present study aimed to investigate the upper trapezius muscle activity during simulated car driving while adopting three different arm positions. Ten participants were instructed to maintain the following positions: hands on the steering wheel (Hands-On), hands not on the steering wheel (Hands-Off) and hands not on the steering wheel but arms on armrests (Armrests). During the tasks, multi-channel surface electromyography (EMG) was recorded from the upper trapezius muscle with 64 two-dimensionally distributed electrodes. Amplitudes of surface EMG in Armrests were lower than in Hands-On (p = 0.004). The spatial distribution of surface EMG changed with time in Hands-Off and Armrests (p < 0.05), but not in Hands-On (p > 0.05). These findings suggest that being freed from steering leads to the recruitment of various muscle fibers/motor units within the upper trapezius muscle and the use of armrests may help reduce the physiological burden loaded on the muscle of drivers.

本研究旨在研究在模拟汽车驾驶过程中采用三种不同的手臂姿势时上斜方肌的活动。十名参与者被要求保持以下姿势：手放在方向盘上（Hands-On），手不在方向盘上（Hands-Off），手不在方向盘上但手臂放在扶手上（Armrests）。在任务期间，使用 64 个二维分布电极从斜方肌上部记录多通道表面肌电图 (EMG)。扶手中的表面 EMG 幅度低于手动操作 ( p  = 0.004)。Hands-Off 和 A​​rmrests 的体表肌电图空间分布随时间变化 ( p  < 0.05)，而 Hands-On 则没有变化 ( p > 0.05)。这些发现表明，从转向中解放出来会导致上斜方肌内各种肌肉纤维/运动单位的募集，而扶手的使用可能有助于减轻驾驶员肌肉上的生理负担。