Abstract
The aim was to investigate whether quantitative job demands influence muscle activity among women, and whether there are gender differences in duration of computer, mouse, and keyboard use and muscle activity of shoulder and forearm muscles during work. The study was carried out in an occupational setting, and 24 women and 11 men from a municipal administration participated. The duration of computer, mouse, and keyboard use was measured by a commercial software package. Quantitative job demands were registered by questionnaire. Electromyography (EMG) was measured bilaterally from the upper trapezius and the extensor digitorum communis muscles. No association was found between self-reported quantitative job demands and muscle activity among the women (n=24). The women used the keyboard more frequently (p=0.020) and tended to perform fewer mouse clicks compared to men (p=0.057), but no difference was seen in EMG activity between men (n=11) and women (n=11) from the same department. However, office assistants (six women) showed significantly higher static EMG activity levels (p=0.042) and almost significantly shorter EMG gap times (p=0.060) than the rest of the subjects (5 women and 11 men). This indicated that shorter muscular resting periods among female office assistants as compared to the other subjects were due to differences in job content rather than gender differences.
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References
Bergqvist U, Wolgast E, Nilsson B, Voss M (1995) The influence of VDT work on musculoskeletal disorders. Ergonomics 38:754–762
Bernard B, Sauter S, Fine L, Petersen M, Hales T (1994) Job task and psychosocial risk factors for work-related musculoskeletal disorders among newspaper employees. Scand J Work Environ Health 20:417–426
Birch L, Juul-Kristensen B, Jensen C, Finsen L, Christensen H (2000) Acute response to precision, time pressure and mental demand during simulated computer work. Scand J Work Environ Health 26:299–305
Bongers PM, de Winter CR, Kompier MAJ, Hildebrandt VH (1993) Psychosocial factors at work and musculoskeletal disease. Scand J Work Environ Health 19:297–312
Burr H (2000) Danskernes anvendelse af computere på arbejdet 1999. National Institute of Occupational Health, Copenhagen, Denmark
Delagi EF, Iazzetti J, Perotto A, Morrison D (1981) Anatomic guide for the electromyographer. Thomas, Springfield, Ill., USA
Fogleman M, Lewis RJ (2002) Factors associated with self-reported musculoskeletal discomfort in video display terminal (VDT) users. Int J Ind Erg 29:311–318
Gerr F, Marcus M, Ensor C, Kleinbaum D, Cohen S, Edwards A, Gentry E, Ortiz DJ, Monteilh C (2002) A prospective study of computer users: I. Study design and incidence of musculoskeletal symptoms and disorders. Am J Ind Med 41:221–235
Hägg GM, Åström A (1997) Load pattern and pressure pain threshold in the upper trapezius muscle and psychosocial factors in medical secretaries with and without shoulder/neck disorders. Int Arch Occup Environ Health 69:423–432
Jensen C, Vasseljen O, Westgaard RH (1993) The influence of electrode position on bipolar surface electromyogram recordings of the upper trapezius muscle. Eur J Appl Physiol 67:266–273
Jensen C, Borg V, Finsen L, Hansen K, Juul-Kristensen B, Christensen H (1998) Job demands, muscle activity and musculoskeletal symptoms in relation to work with the computer mouse. Scand J Work Environ Health 24:418–424
Jensen C, Finsen L, Hansen K, Christensen H (1999) Upper trapezius muscle activity patterns during repetitive manual material handling and work with a computer mouse. J Electromyogr Kinesiol 9:317–325
Jensen C, Finsen L, Søgaard K, Christensen H (2002a) Musculoskeletal symptoms and duration of computer and mouse use. Int J Ind Erg 30:265–275
Jensen C, Ryholt CU, Burr H, Villadsen E, Christensen H (2002b) Work-related psychosocial, physical and individual factors associated with musculoskeletal symptoms in computer users. Work Stress 16:107–120
Jonsson B (1982) Measurement and evaluation of local muscular strain in the shoulder during constrained work. J Hum Ergol 11:73–88
Karlqvist LK, Bernmark E, Ekenvall L, Hagberg M, Isaksson A, Rostö T (1998) Computer mouse position as a determinant of posture, muscular load and perceived exertion. Scand J Work Environ Health 24:62–73
Karlqvist L, Bernmark E, Ekenvall L, Hagberg M, Isaksson A, Rostö T (1999) Computer mouse and trackball operation: similarities and differences in posture, muscular load and perceived exertion. Int J Ind Erg 23:157–169
Kristensen TS, Borg V, Hannerz H (2002) Socioeconomic status and psychosocial work environment: result from a national Danish study. Scand J Public Health 30:41–48
Laursen B, Jensen BR, Sjøgaard G (1998) Effect of speed and precision demands on human shoulder muscle electromyography during a repetitive task. Eur J Appl Physiol 78:544–548
Laursen B, Jensen BR, Ratkevicius A (2001) Performance and muscle activity during computer mouse tasks in young and elderly adults. Eur J Appl Physiol 84:329–336
Marcus M, Gerr F, Monteilh C, Ortiz DJ, Gentry E, Cohen S, Edwards A, Ensor C, Kleinbaum D (2002) A prospective study of computer users: II. Postural risk factors for musculoskeletal symptoms and disorders. Am J Ind Med 41:236–249
Nordander C, Hansson GA, Rylander L, Asterland P, Bystrom JU, Ohlsson K, Balogh I, Skerfving S (2000) Muscular rest and gap frequency as EMG measures of physical exposure: the impact of work tasks and individual related factors. Ergonomics 43:1904–1919
Olsen HB, Christensen H, Søgaard K (2001) An analysis of motor unit firing pattern during sustained low force contraction in fatigued muscle. Acta Physiol Pharmacol Bulg 26:73–78
Polanyi MFD, Cole DC, Beaton DE, Chung J, Wells R, Abdolell M, Beech-Hawley L, Ferrier SE, Mondloch MV, Shields SA, Smith JM, Shannon HS (1997) Upper limb work-related musculoskeletal disorders among newspaper employees: cross-sectional survey results. Am J Ind Med 32:620–628
Punnett L, Bergqvist U (1997) National Institute for Working Life – ergonomic expert committee document no 1. Visual display unit work and upper extremity musculoskeletal disorders. A review of epidemiological findings. In: Kjellberg A (ed) National Institute for Working Life. Solna, Sweden
Veiersted KB, Westgaard RH, Andersen P (1990) Pattern of muscle activity during stereotyped work and its relation to muscle pain. Int Arch Occup Environ Health 62:31–41
Veiersted KB, Westgaard RH, Andersen P (1993) Electromyographic evaluation of muscular work pattern as a predictor of trapezius myalgia. Scand J Work Environ Health 19:284–290
Wahlström J, Svensson J, Hagberg M, Johnson PW (2000) Differences between work methods and gender in computer mouse use. Scand J Work Environ Health 25:390–397
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Blangsted, A.K., Hansen, K. & Jensen, C. Muscle activity during computer-based office work in relation to self-reported job demands and gender. Eur J Appl Physiol 89, 352–358 (2003). https://doi.org/10.1007/s00421-003-0805-7
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DOI: https://doi.org/10.1007/s00421-003-0805-7