使用电子产品对颈部肌肉的影响

为探明使用电子产品对颈部肌肉活动的影响,以8名在校大学生为实验对象,在座位下使用两种屏幕尺寸不同的手机和平板电脑,在手持电子产品或将其放置桌面两种使用方式下,进行阅读、打字和游戏3种不同的操作持续90 s,运用表面肌电系统记录每名实验对象在这12种不同情况下的左右颈斜方肌的表面肌电信号,经过心电信号滤除、全波整流和均方根(RMS)振幅平滑处理后,计算每隔10s的积分肌电值.结果表明:电子产品屏幕越小,颈斜方肌的激活程度越高,但无显著性差异(P>0.05);手持电子产品对颈斜方肌的刺激程度高于将其放置桌面上,但无显著性差异(P>0.05);打字与阅读、打字与游戏两组不同操作对颈斜方肌的刺激程度均有显著性差异(P<0.05),阅读与游戏两组无显著性差异(P>0.05);左、右颈斜方肌在屈颈中被激活的程度不同,并且具有显著性差异(P<0.05).可见电子产品的屏幕尺寸不同、使用方式不同、操作不同等因素对颈部肌肉的活动都产生一定的影响.在特定的坐位下,打字操作对左右颈斜方肌的激活程度最显著,而屏幕尺寸与使用方式的改变对颈部肌肉活动的差异性不显著.研究还发现左、右两侧颈斜方肌的激活程度不对称,长此以往将导致不对称的头颈姿势,进而可能增加颈部肌肉骨骼疾病的风险.

The Impact of Use of Electronic Products on Neck Muscles

To find out the impact of use of electronic products on activity of neck muscles, This study took 8 college students as the experimental subjects. They sat at the table and played with iphone and ipad under two kinds of usage: hand-held them or placing it desktop. They used electronic products to read, type and play games for 90 seconds. In this study, the surface electromyographic testing system was used to record the electromyographic signals of the left and right neck trapezius muscles. The original EMG signals were processed by filtering, full wave rectification and root mean square (RMS) amplitude smoothing, calculated integral electrical values of every 10s. The results showed that the smaller the screen size of electronic products, the higher the activation degree of trapezius, but there was no significant difference (P > 0.05).The degree of stimulation of the trapius muscle by handheld electronic products was higher than that by placing it on the table, but there was no significant difference (P > 0.05).There were significant differences in the stimulation degree of the trapius muscle between the two groups of typing and reading, typing and playing (P < 0.05), while there were no significant differences between the two groups of reading and playing (P > 0.05).The degree of activation of the left and right trapezius muscles in the flexion of the neck were different, and there were significant differences (P < 0.05).It can be seen that the screen size of electronic products, the use of different ways, different operations on the neck muscle activity have a certain impact. The activation degree of the trapezius muscles were the most significant by typing under the specific sitting position, while the changes in screen size and usage modes had no significant difference in neck muscle activity. The study also found asymmetrical activation of the trapezius muscles on the left and right sides of the neck, which in the long run can lead to asymmetrical head and neck postures, and then may increase the risk of musculoskeletal disease in the neck.