The Effect of Keyboard Height on the Muscle Activity of the Upper Trapezius Muscle

  • Lee, Jun-Cheol (Yeungnam University College, Dept. of Physical Therapy) ;
  • Baek, Hong-Seok (Daejeon University, Dept. of Emergency Medical Technology)
  • Received : 2019.06.05
  • Accepted : 2019.06.15
  • Published : 2019.06.30


This study is designed to reduce worker fatigue, improve efficiency and provide a functional working environment based on previous studies that pain occurs in the shoulder area, especially the upper trapezius muscle, when the keyboard height is not appropriate. In this study, the height of the keyboard is four, the height of the elbow and desk is the same height, the height of the desk is 3cm lower than the elbow, the height of the desk is 6cm high, and the height is 9cm high. When working on the keyboard, the wrist and forerunner were organized into four groups of 10 people so that the height was different for each group. When the height of the keyboard is given in various ways compared to the height of the elbow of the subject, it is verified whether there is a difference in the RMS (Root Mean Square) of the upper trapezius muscle. The results of this study showed that the muscle activity of the upper trapezius muscle cap was significant only in the left and right keyboard height -4cm, 0cm, +4cm, +8cm group, but the difference in muscle activity was not significant in the rest group. The first study will require a study of the control of the factors affecting the tension of the subjects, the measurement of muscle activity against various muscles, and whether the length of the shoulder and fingertips of the subject affect muscle activity according to the keyboard type.


Upper trapezius;VDT Syndrome;Keyboard Height;Electromyogram

Table 1. General characteristics of subjects

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Table 2. Comparison of muscle activity of upper trapezius muscle

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