International journal of advanced smart convergence

The Institute of Internet, Broadcasting and Communication (한국인터넷방송통신학회)
권호 표지
DOI QR코드

DOI QR Code

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
Download PDF
⟨ Previous Next ⟩

Abstract

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.

Keywords

Table 1. General characteristics of subjects

OTNBCL_2019_v8n2_211_t0001.png 이미지

Table 2. Comparison of muscle activity of upper trapezius muscle

OTNBCL_2019_v8n2_211_t0002.png 이미지

References

  1. Lee JH, Song YW, Na SH, Jeong MG. Determination of proper monitor height based on the musculoskeletal load and preference during VDT monitoring tasks. Journal of the Korean Institute of Industrial Engineers. Vol. 32, No.3, 236241. 2006.
  2. Woo HK, Moon BY, Cho HK. Ocular symptoms on VDT syndrome and symptoms-related factors. Journal of Korean Ophthalmic Optics Society. Vol.16, No.3, 351-356. 2011.
  3. Kim HJ. The effect of musculoskeletal disease care program at VDT workplace. Hanyang unisersity, Master's Thesis. 2010.
  4. Blangsted AK, Sogaard K, Christensen H, Sjogaard J, The effect of physical and psychosocial loads on the trapezius muscle activity during computer keying tasks and rest periods. Eurjappl Physiol. Vol.91, No- , 253-258. 2004. DOI: https://doi.org/10.1007/s00421-003-0979-z
  5. Lee HK, Park SK, Cho GP, Hong YG. Comparative study on perceptive symptom of video display terminals syndrome between occupational and hobby group. The Journal of Korean Society of Health Sciences. Vol.4, No.1, 17-35. 2007.
  6. Parihar JKS, Jain VK, Chaturvedi P, Kaushik J, Jain G, Pashwini KS. Computer and visual display terminals (VDT) vision syndrome(CVDTS). Medical J Armed Forces INDIA. Vol.72, No.3, 270-276. 2016. DOI: https://doi.org/10.1016/j.mjafi.2016.03.016
  7. Kwon BH, Park GH, Kim W, Kim YM, Choi HG. Analysis of the development of musculoskeletal diseases in Korea(1998-2007). The Korean society of human engineering. Journal of Academic Research. Vol.-, No.- , 28-33. 2008.
  8. Yang SH, Park B, Choi JH. Performance and posture evaluation of ergonomic keyboard. Journal of the Korean Society of Safety. Vol.14, No.4, 168-175. 1999.
  9. Builock MI. Ergonomic: the physiotherapist in the workplace. Churchill Livingstone. 53-181. 1990.
  10. Hamilton N. Source document position as it affects head position and neck muscle tension. Ergonomics. Vol. 39, No. 4, 539-610. 1996. DOI: https://doi.org/10.1080/00140139608964483
  11. Kim MW. A study on the change of attitude and the tension of the trapezius muscle in the upper extremity according to the height and design of the keyboard. Seoul National University. Master's Thesis, 2000.
  12. An CS, Lee MH, An YH. The effect on the tension trapezius muscle of the height keyboard computer. Journal of Korean Society of Physical Therapy. Vol.18, No.6, 67-75. 2006.
  13. Karlqvist LK, Bernmak E, Ekenvall L et al. (1988). Computer mouse use position as a determinant of posture, muscular load and perceived exertion, Scand J Work Environ Health. Vol. 24, No. 1, 62-73. 1998. DOI: https://doi.org/10.5271/sjweh.279
  14. Yoo JY, Ha TH, Soon S, Kim JH. Working posture and muscle tension according to screen position during VDT operation. Annals of Rehabilitation Medicine. Vol.24, No.4, 765-775. 2000.
  15. Hagberg M. Electromyographic signs of the shoulder muscular fatigue in two elevated arm position. Am J of Phy Med. 60(3):111-21. 1981. DOI: https://doi.org/10.5271/sjweh.1579
  16. Larsson EL, Aaro S, Normelli G, Oberg B. Weight distribution in the sitting position in patients with paralytic scoliosis: pre- and postoperative evaluation. EUROPEAN SPINE JOURNAL. Vol.11, No.2, 94-99. 2002. DOI: https://doi.org/10.1007/s00586-001-0373-7
  17. Harvey R, Peper E. (1997). Surface electromyography and mouse use position. Ergo. 40(8):781-789. DOI: https://doi.org/10.1080/001401397187775
  18. Blangsted AK, Sogaard K, Christensen H, Sjogaard J. The effect of physical and psychosocial loads on the trapezius muscle activity during computer keying tasks and rest periods. Eurjappl Physiol. Vol. 91, No. 1, 253-258. 2004. DOI: https://doi.org/10.1007/s00421-003-0979-z
  19. Franklin GM, Friedman AS. Work-related carpal tunnel syndrom. Physical medicine and rehabilitation. Clinics of North America. Vol. 26, No.3, 523-537. 2015.
  20. Song DB, Kim DS, Moon JK. Development of medical evaluation methods and identification of the occurrence and occurrence of cumulative traumatic diseases. A research service report for the prevention of occupational diseases, Korea Occupational Safety Corporation. 1997.
  21. Simoneau GG, Marklin RW, Berman JE. Effect of computer keyboard slope on wrist position and forearm electromyography of typists without musculoskeletal disorders. Physical Therapy. Vol.83, No.9, 816-830. 2003. DOI: https://doi.org/10.1093/ptj/83.9.816
  22. Kargar N, Choobineh AR, Razeghi M, Keshavarzi S, Meftahi N. Posture and discomfort assessment in computer users while using touch screen device as compared with mouse-keyboard and touch pad-keyboard. WORKANDOVER MEDICAL PUBLISHERS INCORPORATED. Vol.59, No.3, 341-349. 2018. DOI: https://doi.org/10.3233/wor-182685
  23. Lee WE. Changes in fatigue and performance error as a function of standing-workable height. Suseong University, Magazine. Vol. 10, No.1, 258-271. 1996.
  24. Park HG, Park SS, Cho NJ. The effect of standard and downward slope of the keyboards on upper trapezius electromyography of typists with taping. Journal of Clinical Electrophysiology. Vol. 6 No.1, 103-114. 2008.
  25. Bendix T. Adjustment of the seated workplace-with special reference to heights and incliations. of seat and table. Danish Medical Bulletin. 34:135-139. 1987.
  26. Jaschinski W. Individual ergonomical design at visual display units: Visual functions and the preferred placement of computer screens. Advances in Occupational Erogonomics & Safety. Vol.1, No. 1, 227-232. 1996. DOI: https://doi.org/10.3403/00229370u
  27. Lim SH, Park HS, Kim HW. Assessing muscle tensions during VDT qorks with surface electromyography. Annals of Occupational and Environmental Medicine. Vol.12, No.4, 524-536. 2000.