Browse > Article
http://dx.doi.org/10.21598/JKPNFA.2021.19.3.391

Effects of a Notebook Computer Supporter on Biomechanical Characteristics in Wrist Joint Muscles of Healthy Young Adults  

Ma, Sung-Ryong (Department of Occupational Therapy College of Natural Science and Public Health and Safety, Chosun Univerisity)
Song, Chiang-Soon (Department of Occupational Therapy College of Natural Science and Public Health and Safety, Chosun Univerisity)
Publication Information
PNF and Movement / v.19, no.3, 2021 , pp. 391-399 More about this Journal
Abstract
Purpose: As laptop use increases throughout the COVID-19 pandemic and its use outside of traditional workstations proliferates, it is imperative to expand the limited research available regarding ergonomic exposure. This study aimed to identify the effects of a laptop supporter on biomechanical characteristics in the wrist joint muscles of healthy young adults. Methods: This was a cross-sectional observational study design with thirty-four healthy young adults as participants. They conducted a typing exercise performed under two different conditions, which were with and without a notebook computer supporter. This study measured the biomechanical characteristics of the muscles of the wrist joints including the flexor carpi ulnaris (FCU), the flexor carpi radialis (FCR), the extensor carpi radialis longus (ECRL), and the extensor carpi ulnaris (ECU). Measurements were taken three times: before typing, immediately after typing for 30 minutes with a supporter, and immediately after typing for 30 minutes without a supporter. The statistical method to compare the three different measurement conditions was the repeated measures ANOVA. Results: The participants showed significantly different levels of dynamic stiffness in both the FCU before typing and immediately after 30 minutes of typing with a supporter, and showed significantly different levels of dynamic stiffness in the FCR before typing and immediately after 30 minutes of typing with a supporter. The dynamic stiffness level immediately after 30 minutes of typing without a supporter was significantly different than that immediately after 30 minutes of typing with a supporter. However, the muscle tone was not significantly different among the three different conditions. Conclusion: The results of this study revealed that a laptop supporter used to correct the eye level of the electronic screen increases the dynamic stiffness of the wrist joint flexors, so it is necessary to consider the neutral position of the wrist joint during typing.
Keywords
Biomechanics; Muscle; Notebook peripherals; Young Adults; Wrist joint;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 Asundi K, Odell D, Luce A, et al. Changes in posture through the use of simple inclines with notebook computers placed on a standard desk. Applied Ergonomics. 2012;43(2):400-407.   DOI
2 Canalys. Global PC market Q4 2020. https://www.canalys.com/newsroom/canalys-global-pc-market-Q4-2020. 2021.
3 Dzaky M, Ma F. Real-time muscle fatigue monitoring based on median frequency of electromyography signal. In 5th International Conference on Instrumentation, Control, and Automation (ICA). 2017;135-139.
4 Kang OH, Lee SR, Heo GS, et al., Study on estimation of muscle f atigue u sing f oot pressure a nd EMG. Preceedings of the Autum Conference on Korean Society for Precision Engineering. 2012;1203-1204.
5 Jung S, Chae Y, Roh S. Comparing the characteristics of CTS by the frequency of exposure to wrist-burdening work: CTS surveillance system, 2001-2004. Korean Journal of Occupational Environment and Medicine. 2010;22(2):85-94.   DOI
6 Roll SC, Hardison ME. Effectiveness of occupational therapy interventions for adults with musculoskeletal conditions of the forearm, wrist and hand: a systematic review. American Journal of Occupational Therapy. 2017;71(1):7101180010p1-7101180010p2.   DOI
7 Wikipedia. Laptop computer. www.enwikipedia.org/wiki/laptop. 2021.
8 Kim WT. Analysis of EMG change in wrist muscles by using a wrist splint and an ergonomic keyboard. Daegu University. Dissertation of Master's Degree, 2011.
9 Hoang C. A thesis submitted to the faculty of graduate studies in partial fulfillment of the requirements. York University. Dissertation of Master's Degree. 2016.
10 Kim MH, Yoo WG. Effects of a visual feedback device for hip adduction on trunk muscles and sitting posture in visual display terminal workers. Asia-Pacific Journal of Public Health. 2011;23(3):378-385.   DOI
11 Lee DH, Kang B, Choi S, et al. Change in musculoskeletal pain in patients with work-related musculoskeletal disorder after tailored rehabilitation education: a one-year follow-up survey. Annals of Rehabilitation Medicine. 2015;39(5):726-734.   DOI
12 Lee H. A study on muscle activity and fatigue change pattern on short time isometric works. University of Seoul. Dissertation of Master's Degree, 2006.
13 Lee WE. Effect of distance between trunk and desk on forward head posture and muscle activity of neck and shoulder muscles during computer work. Journal of the Korean Society of Physical Medicine. 2013;8(4):601-608.   DOI
14 Loghmani A, Golshiri P, Zamani A, et al. Musculoskeletal symptoms and job satisfaction among office-workers: a cross-sectional study from Iran. Acta Medica Academica. 2013;42(1):46-54.   DOI
15 Nejati P, Lotfian S, Moezy A, et al. The study of correlation between forward head posture and neck pain in Iranian office workers. International Journal of Occupational Medicine and Environmental Health. 2015;28(2): 295-303.
16 Occupational Safety and Health Act. www.law.co.kr. 2021.
17 Parihar JKS, Jain VK, Chaturvedi P, et al., Computer and visual display terminals (VDT) vision syndrome (CVDTS). Medical Journal Armed Forces India. 2016;72(3):270-276.   DOI
18 Cho YK, Hwang S. The effect of computer monitor height on flexion-relaxation phenomenon in the cervical spine. Holistic Health Science. 2014;4(1):25-33.
19 Alyami H, Albarrati AM. Comparison of spinal angles in a typing task on a laptop and a desktop computer: a preliminary study. The American Journal of Occupational Therapy. 2016;70(6):1-5.
20 Lee J, Chee Y, Bae J , et a l. The wearable sensor s ystem to monitor the head and neck posture in daily life. Journal of Biomedical Engineering Research. 2016;37(2):112-118.   DOI
21 Roh SW, Park JW, Han SH, et al. Health-related quality of life and upper extremity pain in workers using computer. Journal of the Korean Academy of Rehabilitation Medicine. 2010; 34(3):325-335.
22 Ereline J, Rarenson K, Vahtrik D, et al., Skeletal muscle tone and motor performance characteristics in dentists as compared to controls. Agronomy Research. 2017;15(4): 1571-1581.
23 Asundi K, Odell D, Luce A, et al. Notebook computer use on a desk, lap and support: effects on posture, performance and comfort. Ergonomics. 2010;53(1): 74-82.   DOI
24 Aydin NS, Dilbay NK, Selcuk H, et al. Muscue activation of the upper trapezius and functional typing performance during computer typing task: a comparison of two different wrist immobilization methods. Journal of Bodywork & Movement Therapies. 2021;27(3):472-476.   DOI
25 Caneiro JP, O'Sullivan P, Burnett A, et al. The influence of different sitting postures on head/neck posture and muscle activity. Manual Therapy. 2010;15(1):54-60.   DOI
26 Ardiyanto A, Subagyo S, Herianto H. Effect of wrist extension angles and low-velocity ulnar deviation movements on forearm muscle activity. Proceedings of the XXXth Annual Occupational Ergonomics and Safety Conference. 2018.