工程科学学报.第41卷，第11期：1493-1500.2019年11月 Chinese Journal of Engineering,Vol.41,No.11:1493-1500,November 2019 DOI:10.13374/j.issn2095-9389.2019.04.24.007;http://journals.ustb.edu.cn 长时间颈部前屈对颈部肌肉疲劳的影响 徐明伟，金龙哲四，于露，刘建国，张安琪 北京科技大学土木与资源工程学院，北京100083 ☒通信作者，E-mail:忉jin@ustb.edu.cn 摘要长期颈部前屈对颈椎造成严重影响.为定量评估长时间低头对颈椎疲劳造成的影响，选取20名健康受试者，保持低 头角度40°~60°持续3.选择胸锁乳突肌.颈部夹肌和肩部斜方肌测量其表面肌电信号.经滤波、整流、振幅标准化等处理 后，对每60s的肌电值进行积分和求其平均功率频率.研究发现，积分肌电值的波动变化具有规律性，首次增大后的减小表 征肌肉进入疲劳状态；不同肌肉的平均功率频率(mean power frequency,.MPF)值具有明显差异，决定着该肌肉疲劳耐受性的 持续时间，且在整个颈部前屈过程中MPF并非简单的线性关系.提出用MP℉的导数来提取疲劳特征，用窗口化的MPP负数 累积判定肌肉疲劳.结果表明，MP℉负数累积能很好地判断肌肉疲劳，胸锁乳突肌在20in内出现最终疲劳，而颈部夹肌和 肩部斜方肌在20min左右出现了短暂性疲劳，随后在75~100mi时又出现了最终疲劳.因此建议持续颈部前屈时长不超 过20min. 关键词表面肌电：颈椎疲劳：疲劳特征：肌电积分：平均功率频率 分类号TG142.71 Effect of long-term bowing of the head on neck muscle fatigue XU Ming-wei,JIN Long-zhe YU Lu,LIU Jian-guo,ZHANG An-qi School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China Corresponding author,E-mail:Izjin@ustb.edu.cn ABSTRACT Long-term neck flexion posture is a common awkward posture resulting from long-term head-down work,long-term looking at a computer screen,and long-term playing with a mobile phone.Fatigue and chronic injury of cervical muscles are easily caused by long-term bowing of the head.Long-term bowing of the head to play with a mobile phone causes injury to the cervical spine. Long-term neck muscle contraction is an important cause of fatigue and chronic injury of the neck muscles and tissues.Therefore,it is of significance to analyze the changes of muscle activity during long-term neck muscle contraction and to determine the time threshold of neck muscle fatigue to reduce the damage caused by neck muscle fatigue.To quantitatively evaluate the effect of long-term head-down playing with a mobile phone on cervical spine fatigue,20 healthy subjects were selected and kept the head-down angle between 40 and 60 for 3 h.On the basis of the analysis of cervical spine muscle architecture and anthropometry,the surface electromyography (sEMG) of the sternocleidomastoid,cervical gripper,and shoulder trapezius muscles was recorded.The original sEMG data were processed by filtering,rectifying,and amplitude standardization.The EMG values every 60s were integrated,and their mean power frequency(MPF) was calculated.Results show that the fluctuation of the integral EMG is regular and the decrease after the initial increase indicates that the muscle is in the fatigue state.The MPF values of different muscles have obvious differences,which determine the duration of fatigue tolerance of the muscle.Moreover,the MPF does not exhibit a simple linear relationship during the entire bowing process.The results also show that negative MPF accumulation can be used to assess neck muscle fatigue.The sternocleidomastoid muscle is in the fatigue state in 20 min,whereas the cervical gripper and shoulder trapezius muscles are temporarily fatigued in approximately 20 min and in the 收稿日期：2019-04-24 基金项目：国家重点研发计划课题资助项目(2016YFC0801700)长时间颈部前屈对颈部肌肉疲劳的影响 徐明伟，金龙哲苣，于    露，刘建国，张安琪 北京科技大学土木与资源工程学院，北京 100083 苣通信作者，E-mail: lzjin@ustb.edu.cn 摘    要    长期颈部前屈对颈椎造成严重影响. 为定量评估长时间低头对颈椎疲劳造成的影响，选取 20 名健康受试者，保持低 头角度 40°～60°持续 3 h. 选择胸锁乳突肌，颈部夹肌和肩部斜方肌测量其表面肌电信号. 经滤波、整流、振幅标准化等处理 后，对每 60 s 的肌电值进行积分和求其平均功率频率. 研究发现，积分肌电值的波动变化具有规律性，首次增大后的减小表 征肌肉进入疲劳状态；不同肌肉的平均功率频率 (mean power frequency，MPF) 值具有明显差异，决定着该肌肉疲劳耐受性的 持续时间，且在整个颈部前屈过程中 MPF 并非简单的线性关系. 提出用 MPF 的导数来提取疲劳特征，用窗口化的 MPF 负数 累积判定肌肉疲劳. 结果表明，MPF 负数累积能很好地判断肌肉疲劳，胸锁乳突肌在 20 min 内出现最终疲劳，而颈部夹肌和 肩部斜方肌在 20 min 左右出现了短暂性疲劳，随后在 75～100 min 时又出现了最终疲劳. 因此建议持续颈部前屈时长不超 过 20 min. 关键词    表面肌电；颈椎疲劳；疲劳特征；肌电积分；平均功率频率 分类号    TG142.71 Effect of long-term bowing of the head on neck muscle fatigue XU Ming-wei，JIN Long-zhe苣 ，YU Lu，LIU Jian-guo，ZHANG An-qi School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China 苣 Corresponding author, E-mail: lzjin@ustb.edu.cn ABSTRACT    Long-term  neck  flexion  posture  is  a  common  awkward  posture  resulting  from  long-term  head-down  work,  long-term looking  at  a  computer  screen,  and  long-term  playing  with  a  mobile  phone.  Fatigue  and  chronic  injury  of  cervical  muscles  are  easily caused by long-term bowing of the head. Long-term bowing of the head to play with a mobile phone causes injury to the cervical spine. Long-term neck muscle contraction is an important cause of fatigue and chronic injury of the neck muscles and tissues. Therefore, it is of significance to analyze the changes of muscle activity during long-term neck muscle contraction and to determine the time threshold of neck muscle fatigue to reduce the damage caused by neck muscle fatigue. To quantitatively evaluate the effect of long-term head-down playing with a mobile phone on cervical spine fatigue, 20 healthy subjects were selected and kept the head-down angle between 40° and 60° for 3 h. On the basis of the analysis of cervical spine muscle architecture and anthropometry, the surface electromyography (sEMG) of the sternocleidomastoid, cervical gripper, and shoulder trapezius muscles was recorded. The original sEMG data were processed by filtering, rectifying, and amplitude standardization. The EMG values every 60 s were integrated, and their mean power frequency (MPF) was calculated. Results show that the fluctuation of the integral EMG is regular and the decrease after the initial increase indicates that the muscle is in the fatigue state. The MPF values of different muscles have obvious differences, which determine the duration of fatigue tolerance of the muscle. Moreover, the MPF does not exhibit a simple linear relationship during the entire bowing process. The results also show that negative MPF accumulation can be used to assess neck muscle fatigue. The sternocleidomastoid muscle is in the fatigue state in 20 min, whereas the cervical gripper and shoulder trapezius muscles are temporarily fatigued in approximately 20 min and in the 收稿日期: 2019−04−24 基金项目: 国家重点研发计划课题资助项目 (2016YFC0801700) 工程科学学报，第 41 卷，第 11 期：1493−1500，2019 年 11 月 Chinese Journal of Engineering, Vol. 41, No. 11: 1493−1500, November 2019 DOI：10.13374/j.issn2095-9389.2019.04.24.007; http://journals.ustb.edu.cn