Stress and fatigue characteristics of neck muscles in lateral flexion posture in confined space

Abstract

In order to reduce incidence of occupational muscular disorders since musculoskeletal injury has become one of the key problems in prevention and control of occupational diseases in Chinaꎬ firstlyꎬ a neck musculoskeletal model was established by AnyBody platformꎬ and stress of muscles in lateral flexion position of neck was obtained through reverse dynamics simulation analysis. Thenꎬ 8 healthy subjects were selectedꎬ electromyographic signals of their sternocleidomastoid and trapezius muscles were collected with sEMG technologyꎬ and median frequency (MF) was used as an indicator to assess muscle fatigue based on MF decline rate. Finallyꎬ by setting up different temperature and humidityꎬ effects of high temperature and humidity environment in confined space on neck muscle fatigue were investigated. The results show that with the increase of lateral flexion angleꎬ load of neck muscles is increasing graduallyꎬ and fatigue rate becomes faster. At the same timeꎬ high temperature and humidity working environment will also accelerate fatigue of neck muscles under lateral flexion posture. 第 6 期 张壹泓等: 有限空间环境下颈部侧屈肌肉受力与疲劳特征