Document Type : Original Article

Authors

1 Department of Ergonomics, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran

2 Research Center for Health Sciences, Institute of Health, Shiraz University of Medical Sciences, Shiraz, Iran

3 Department of Physiotherapy, School of Rehabilitation Sciences, Shiraz University of Medical Sciences, Shiraz, Iran

4 Institute of Mechanics, College of Technology and Engineering of Shiraz, Shiraz, Iran

Abstract

Background: Musculoskeletal disorders in the upper extremities are common among computer users. This study aimed to assess the effect of mouse pad angle on the forearm muscles activity and upper limb discomfort.
Methods: This is an experimental research design. The mouse pad was set at 0, 10, 20, and 30 degrees of forearm supination. Ten subjects performed an identical text editing task with mouse in each pad position. Electrical activity of the selected forearm muscles was recorded with surface electrodes. 10-point rating scales were used for assessing perceived discomfort.
Results: Extensor Carpi Radialis had the lowest mean of Electromyography (EMG) values in the 0° slanted pad (5.94), and the highest values were associated with Pronator Quadratus in 0-degree slanted pad (22.29). The highest and the lowest mean (SD) of the users’ upper limb discomfort were 3.70 (1.63) and 1.90 (1.28) in 30° and 10° slanted pads, respectively.
Conclusion: Using slanted mouse pads could be a helpful and practical tool for office workers to keep more neutral wrist/hand positions.

Keywords

  1. Gonçalves JS, Shinohara Moriguchi C, Takekawa KS, Coury HJCG, Sato TO. The effects of forearm support and shoulder posture on upper trapezius and anterior deltoid activity. J Phys Ther Sci. 2017;29(5):793-8. doi: 10.1589/jpts.29.793. PMID: 28603347; PMCID: PMC5462674.
  2. Jovanović S, Šimunič B. Effect of ergonomic Armrest forearm support on wrist posture related to carpal tunnel pressure during computer mouse work. Int J Ind Ergon. 2021;86:103220. doi: 10.1016/j.ergon.2021.103220.
  3. Sako S, Sugiura H, Tanoue H, Kojima M, Kono M, Inaba R. Electromyographic analysis of relevant muscle groups during completion of computer tasks using different computer mouse positions. Int J Occup Saf Ergon. 2017;23(2):267-73. doi: 10.1080/10803548.2016.1275140. PMID: 28002978.
  4. Gonçalves JS, Moriguchi CS, Takekawa KS, Sato TO. Effects of work surface and task difficulty on neck-shoulder posture and trapezius activity during a simulated mouse task. Int J Occup Saf Ergon. 2019;25(1):86-90. doi: 10.1080/10803548.2018.1438960. PMID: 29424654.
  5. Clarisse G, Cail F, Pascal W. Comparing learning during the familiarization phase with a slanted mouse and a vertical mouse when performing a repeated pointing-clicking task. Int J Occup Saf Ergon. 2022;28(1):333-42. doi: 10.1080/10803548.2020.1754637. PMID: 32270750.
  6. Emerson S, Emerson K, Fedorczyk J. Computer workstation ergonomics: Current evidence for evaluation, corrections, and recommendations for remote evaluation. J Hand Ther. 2021;34(2):166-78. doi: 10.1016/j.jht.2021.04.002. PMID: 34030954.
  7. Sánchez-Brau M, Domenech-Amigot B, Brocal-Fernández F, Quesada-Rico JA, Seguí-Crespo M. Prevalence of Computer Vision Syndrome and Its Relationship with Ergonomic and Individual Factors in Presbyopic VDT Workers Using Progressive Addition Lenses. Int J Environ Res Public Health. 2020;17(3):1003. doi: 10.3390/ijerph17031003. PMID: 32033372; PMCID: PMC7038098.
  8. Dehghan N, Choobineh A, Razeghi M, Hasanzadeh J, Irandoost M. Designing a new computer mouse and evaluating some of its functional parameters. J Res Health Sci. 2014;14(2):132-5. PMID: 24728748.
  9. Coelho DA, Lourenço ML. A tentative efficiency index for pointing device use in computer aided design: A pilot study. Work. 2018;61(1):157-70. doi: 10.3233/WOR-182785. PMID: 30223418.
  10. Johnson P. DJ, Hews J., Rempel D. Office Ergonomics: Motion Analysis of Computer Mouse Usage. Proceedings of the American Industrial Hygiene Conference and Exposition; Fairfax, VA: AIHA1993. CRID: 1570009750641418368.
  11. Hemati K, Mirjalili S, Ghasemi MS, Abdolahian Y, Siroos R, Sanati P, et al. Functional parameters, wrist posture deviations and comfort: A comparison between a computer mouse and a touch pen as input devices. Work. 2020;65(4):701-6. doi: 10.3233/WOR-203124. PMID: 32333572.
  12. Chaparro A, Rogers M, Fernandez J, Bohan M, Choi SD, Stumpfhauser L. Range of motion of the wrist: implications for designing computer input devices for the elderly. Disabil Rehabil. 2000;22(13-14):633-7. doi: 10.1080/09638280050138313. PMID: 11052213.
  13. Andersen JH, Fallentin N, Thomsen JF, Mikkelsen S. Risk factors for neck and upper extremity disorders among computers users and the effect of interventions: an overview of systematic reviews. PLoS One. 2011;6(5):e19691. doi: 10.1371/journal.pone.0019691. PMID: 21589875; PMCID: PMC3093401.
  14. Lee DL, McLoone H, Dennerlein JT. Observed finger behaviour during computer mouse use. Appl Ergon. 2008;39(1):107-13. doi: 10.1016/j.apergo.2006.12.008. PMID: 17400173.
  15. Coenen P, van der Molen HF, Burdorf A, Huysmans MA, Straker L, Frings-Dresen MH, et al. Associations of screen work with neck and upper extremity symptoms: a systematic review with meta-analysis. Occup Environ Med. 2019;76(7):502-9. doi: 10.1136/oemed-2018-105553. PMID: 30894425.
  16. Radwan A, Kallasy T, Monroe A, Chrisman E, Carpenter O. Benefits of alternative computer mouse designs: A systematic review of controlled trials. Cogent Eng. 2018;5(1):1521503. doi: 10.1080/23311916.2018.1521503
  17. Jensen C, Finsen L, Søgaard K, Christensen H. Musculoskeletal symptoms and duration of computer and mouse use. Int J Ind Ergon. 2002;30(4):265-75. doi: 10.1016/S0169-8141(02)00130-0.
  18. Andersen JH, Thomsen JF, Overgaard E, Lassen CF, Brandt LP, Vilstrup I, et al. Computer use and carpal tunnel syndrome: a 1-year follow-up study. JAMA. 2003;289(22):2963-9. doi: 10.1001/jama.289.22.2963. PMID: 12799404.
  19. Karlqvist L, Tornqvist EW, Hagberg M, Hagman M, Toomingas A. Self-reported working conditions of VDU operators and associations with musculoskeletal symptoms: a cross-sectional study focussing on gender differences Int J Ind Ergon. 2002;30(4–5):277-94. doi: 10.1016/S0169-8141(02)00131-2.
  20. Lin MY, Young JG, Dennerlein JT. Evaluating the effect of four different pointing device designs on upper extremity posture and muscle activity during mousing tasks. Appl Ergon. 2015;47:259-64. doi: 10.1016/j.apergo.2014.10.003. PMID: 25479996.
  21. MJ S. History of work-related musculoskeletal disorders. New York: Tailor and Francis; 2001.
  22. Cook C, Burgess-Limerick R, Papalia S. The effect of wrist rests and forearm support during keyboard and mouse use. Int J Ind Ergon. 2004;33(5):463-72. doi: 10.1016/j.ergon.2003.12.002.
  23. Lee YH, Su MC. Design and validation of a desk-free and posture-independent input device. Appl Ergon. 2008;39(3):399-406. doi: 10.1016/j.apergo.2005.04.006. PMID: 18022139.
  24. Aptel M, Aublet-Cuvelier A, Cnockaert JC. Work-related musculoskeletal disorders of the upper limb. Joint Bone Spine. 2002;69(6):546-55. doi: 10.1016/s1297-319x(02)00450-5. PMID: 12537261.
  25. Onyebeke LC, Young JG, Trudeau MB, Dennerlein JT. Effects of forearm and palm supports on the upper extremity during computer mouse use. Appl Ergon. 2014;45(3):564-70. doi: 10.1016/j.apergo.2013.07.016. PMID: 24054504.
  26. Wang X, Lavender SA, Sommerich CM, Rayo MF. The effects of using a footrest during computer tasks varying in complexity and temporal demands: A postural and electromyographic analysis. Appl Ergon. 2022;98:103550. doi: 10.1016/j.apergo.2021.103550. PMID: 34450458.
  27. Shahwan BS, D'emeh WM, Yacoub MI. Evaluation of computer workstations ergonomics and its relationship with reported musculoskeletal and visual symptoms among university employees in Jordan. Int J Occup Med Environ Health. 2022;35(2):141-56. doi: 10.13075/ijomeh.1896.01822. PMID: 34605825.
  28. Chen HM, Leung CT. The effect on forearm and shoulder muscle activity in using different slanted computer mice. Clin Biomech (Bristol, Avon). 2007;22(5):518-23. doi: 10.1016/j.clinbiomech.2007.01.006. PMID: 17360086.
  29. Zipp P, Haider E, Halpern N, Rohmert W. Keyboard design through physiological strain measurements. Appl Ergon. 1983;14(2):117-22. doi: 10.1016/0003-6870(83)90158-8. PMID: 15676472.
  30. Gaudez C, Cail F. Effects of mouse slant and desktop position on muscular and postural stresses, subject preference and performance in women aged 18-40 years. Ergonomics. 2016;59(11):1473-86. doi: 10.1080/00140139.2016.1148783. PMID: 26847952.
  31. Houwink A, Oude Hengel KM, Odell D, Dennerlein JT. Providing training enhances the biomechanical improvements of an alternative computer mouse design. Hum Factors. 2009;51(1):46-55. doi: 10.1177/0018720808329843. PMID: 19634308.
  32. Lourenço ML, Lanhoso F, Coelho DA. Usability Evaluation of Slanted Computer Mice. Int J Environ Res Public Health. 2021;18(8):3854. doi: 10.3390/ijerph18083854. PMID: 33916935; PMCID: PMC8067547.
  33. Bridger R. Introduction to Human Factors and Ergonomics. Boca Raton: CRC Press; 2017.
  34. Cram JR. Cram's introduction to surface electromyography. Boston: Jones & Bartlett Learning; 2011.
  35. Gustafsson E, Hagberg M. Computer mouse use in two different hand positions: exposure, comfort, exertion and productivity. Appl Ergon. 2003;34(2):107-13. doi: 10.1016/S0003-6870(03)00005-X. PMID: 12628567.
  36. Hedge A, Feathers D, Rollings K. Ergonomic Comparison of Slanted and Vertical Computer Mouse Designs. Proceedings of the Human Factors and Ergonomics Society Annual Meeting. 2010;54(6):561-5.
  37. Labbafinejad Y, Eslami-Farsani M, Mohammadi S, Ghasemi MS, Reiszadeh M, Dehghan N. Evaluating Muscle Activity During Work With Trackball, Trackpad, Slanted, and Standard Mice. Iran Rehabil J. 2019;17(2):121-8.
  38. St-Onge N, Samani A, Madeleine P. Integration of active pauses and pattern of muscular activity during computer work. Ergonomics. 2017;60(9):1228-39. doi: 10.1080/00140139.2017.1303086. PMID: 28304226.
  39. Visser B, de Korte E, van der Kraan I, Kuijer P. The effect of arm and wrist supports on the load of the upper extremity during VDU work. Clin Biomech (Bristol, Avon). 2000;15 Suppl 1:S34-8. doi: 10.1016/s0268-0033(00)00058-9. PMID: 11078904.
  40. Salmani Nodooshan H, Choobineh A, Razeghi M, Shahnazar Nezhad Khales T. Designing, prototype making and evaluating a mechanical aid device for patient transfer between bed and stretcher. Int J Occup Saf Ergon. 2017;23(4):491-500. doi: 10.1080/10803548.2016.1274161. PMID: 28041534.