Abstract
Most occupational tasks involve some level of mental/cognitive processing in addition to physical work; however, the etiology of work-related musculoskeletal disorders (WMSDs) due to these demands remains unclear. The aim of this study was to quantify the interactive effects of physical and mental workload on muscle endurance, fatigue, and recovery during intermittent work. Twelve participants, balanced by gender, performed intermittent static shoulder abductions to exhaustion at 15, 35, and 55% of individual maximal voluntary contraction (MVC), in the absence (control) and presence (concurrent) of a mental arithmetic task. Changes in muscular capacity were determined using endurance time, strength decline, electromyographic (EMG) fatigue indicators, muscle oxygenation, and heart rate measures. Muscular recovery was quantified through changes in strength and physiological responses. Mental workload was associated with shorter endurance times, specifically at 35% MVC, and greater strength decline. EMG and oxygenation measures showed similar changes during fatigue manifestation during concurrent conditions compared to the control, despite shorter endurance times. Moreover, decreased heart rate variability during concurrent demand conditions indicated increased mental stress. Although strength recovery was not influenced by mental workload, a slower heart rate recovery was observed after concurrent demand conditions. The findings from this study provide fundamental evidence that physical capacity (fatigability and recovery) is adversely affected by mental workload. Thus, it is critical to determine or evaluate occupational demands based on modified muscular capacity (due to mental workload) to reduce risk of WMSD development.
Similar content being viewed by others
References
Ahsberg E, Gamberale F, Gustafsson K (2000) Perceived fatigue after mental work: an experimental evaluation of a fatigue inventory. Ergonomics 43(2):252–268
Ando S, Kokubu M, Yamada Y, Kimura M (2011) Does cerebral oxygenation affect cognitive function during exercise? Eur J Appl Physiol 1–10
Åstrand I (1967) Degree of strain during building work as related to individual aerobic work capacity. Ergonomics 10(3):293–303
Ayaz H, Shewokis PA, Bunce S, Izzetoglu K, Willems B, Onaral B (2011) Optical brain monitoring for operator training and mental workload assessment. NeuroImage
Beauchet O, Kressig RW, Najafi B, Aminian K, Dubost V, Mourey F (2003) Age related decline of gait control under a dual task condition. J Am Geriatr Soc 51(8):1187–1188
Bernard BP (1997) Musculoskeletal disorders and workplace factors: a critical review of epidemiologic evidence for work-related musculoskeletal disorders of the neck, upper extremity, and low back. U.S. Department of Health and Human Services CDC (NIOSH), Publication No. 97-141
BLS (2008) Number and incidence rate of nonfatal occupational injuries and illnesses involving days away from work by selected worker and case characteristics and musculoskeletal disorders. Retrieved 4 May 2010. http://www.bls.gov/news.release/pdf/osh2.pdf
Boksem MAS, Meijman TF, Lorist MM (2006) Mental fatigue, motivation and action monitoring. Biol Psychol 72(2):123–132
Bongers PM, de Winter CR, Kompier MAJ, Hildebrandt VH (1993) Psychosocial factors at work and musculoskeletal disease. Scand J Work Environ Health 19(5):297–312
Borg G (1982) A category scale with ratio properties for intermodal and inter-individual comparisons. In: Geissler HG, Petzold P (eds) Psychophysical judgment and the process of perception. VEB Deutscher Verlag der Wissenschaften, Berlin, pp 25–34
Borg G (1990) Psychophysical scaling with applications in physical work and the perception of exertion. Scand J Work Environ Health 16:55
Callister R, Suwarno NO, Seals DR (1992) Sympathetic activity is influenced by task difficulty and stress perception during mental challenge in humans. J Physiol 454(1):373
Chaudhuri A, Behan PO (2000) Fatigue and basal ganglia. J Neurol Sci 179(1–2):34–42
Christou EA, Carlton LG (2002) Age and contraction type influence motor output variability in rapid discrete tasks. J Appl Physiol 93:489–498
Davis KG, Marras WS, Heaney CA, Waters TR, Gupta P (2002) The impact of mental processing and pacing on spine loading. Spine 27(23):2645–2653
De Luca CJ (1997) The Use of Surface Electromyography in Biomechanics. J Appl Biomech 13:135–163
Dettmers C, Lemon R, Stephen K, Fink G, Frackowiak R (1996) Cerebral activation during the exertion of sustained static force in man. Neuroreport 7(13):2103
Enoka R, Christou E, Hunter S, Kornatz K, Semmler J, Taylor A, Tracy B (2003) Mechanisms that contribute to differences in motor performance between young and old adults. J Electromyogr Kinesiol 13:1–12
Fitts RH (1996) Muscle fatigue: the cellular aspects. Am J Sports Med 24:S9–S13
Flodgren G, Crenshaw A, Gref M, Fahlstrom M (2009) Changes in interstitial noradrenaline, trapezius muscle activity and oxygen saturation during low-load work and recovery. Eur J Appl Physiol 107(1):31–42
Gandevia SC (2001) Spinal and supraspinal factors in human muscle fatigue. Physiol Rev 81(4):1725–1789
Garg A, Hegmann K, Schwoerer B, Kapellusch J (2002) The effect of maximum voluntary contraction on endurance times for the shoulder girdle. Int J Ind Ergonomics 30(2):103–113
Gerra G, Zaimovic A, Mascetti GG, Gardini S, Zambelli U, Timpano M, Brambilla F (2001) Neuroendocrine responses to experimentally-induced psychological stress in healthy humans. Psychoneuroendocrinology 26(1):91–107
Guillot A, Haguenauer M, Dittmar A, Collet C (2005) Effect of a fatiguing protocol on motor imagery accuracy. Eur J Appl Physiol 95:186–190
Hagberg M (1981) Muscle endurance and surface electromyography in isometric and dynamic exercise. J Appl Physiol 51:1–7
Hainaut K, Duchateau J (1989) Muscle fatigue, effects of training and disuse. Muscle Nerve 12:660–669
Hjortskov N, Rissen D, Blangsted AK, Fallentin N, Lundberg U, Søgaard K (2004) The effect of mental stress on heart rate variability and blood pressure during computer work. Eur J Appl Physiol 92:84–89
Holding D (1983) Fatigue. In: Hockey GRJ (ed) Stress and fatigue in human performance. John Wiley, New York, pp 145–167
Kamath MV, Fallen EL (1993) Power spectral analysis of heart rate variability: a noninvasive signature of cardiac autonomic function. Crit Rev Biomed Eng 21:245–311
Kilborn A (1971) Physical training in women. Scand J Clin Lab Invest 28(suppl):119
Laursen B, Jensen BR, Garde AH, Jorgensen AH (2002) Effect of mental and physical demands on muscular activity during the use of a computer mouse and a keyboard. Scand J Work Environ Health 28:215–221
Lorist M, Kernell D, Meijman T, Zijdewind I (2002) Motor fatigue and cognitive task performance in humans. J Physiol 545(1):313
Lundberg U (2002) Psychophysiology of work: stress, gender, endocrine response, and work-related upper extremities disorders. Am J Ind Med 41:383–392
Lundberg U, Forsman M, Zachau G, Ekloèf M, Palmerud G, Melin B, Kadefors R (2002) Effects of experimentally induced mental and physical stress on motor unit recruitment in the trapezius muscle. Work Stress 16(2):166–178
Luximon A, Goonetilleke RS (2001) Simplified subjective workload assessment technique. Ergonomics 44(3):229–243
Macdonell CW, Keir PJ (2005) Interfering effects of the task demands of grip force and mental processing on isometric shoulder strength and muscle activity. Ergonomics 48(15):1749–1769
Malik M, Bigger J, Camm A, Kleiger R, Malliani A, Moss A, Schwartz P (1996) Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Heart rate variability: standards of measurement, physiological interpretation, and clinical use. Circulation 93(5):1043
Marras WS, Davis KG, Heaney CA, Maronitis AB, Allread WG (2000) The influence of psychosocial stress, gender, and personality on mechanical loading of the lumbar spine. Spine 25(23):3045–3054
McLean L, Quhart NU (2002) The influence of psychological stressors on myoelectrical signal activity in the shoulder region during a data entry task. Work Stress 16(2):138–153
Mehta RK, Agnew MJ (2011a) Effects of concurrent physical and mental demands for a short duration static task. Int J Ind Ergonomics 41(5):488–493
Mehta RK, Agnew MJ (2011b) Exertion-dependent effects of physical and mental workload on physiological outcomes and task performance. Accepted for publication in the IIE Trans Occup Ergonomics Hum Factors
Melin B, Lundberg U (1997) A biopsychosocial approach to work-stress and musculoskeletal disorders. J Psychophysiol 11:238–247
Merletti R, Lo Conte LR (1995) Advances in processing of surface myoelectric signals: part 1. Med Biol Eng Comput 33:362–372
Meshkati N (1988) Heart rate variability and mental workload assessment. In: Hancock PA, Meshkati N (eds) Human mental workload. Elsevier, North-Holland
Milner-Brown H, Mellenthin M, Miller R (1986) Quantifying human muscle strength, endurance and fatigue. Arch Phys Med Rehabil 67(8):530
Perotto D (1994) Anatomical guide for the electromyographer: the limbs and trunk, 3rd edn. Charles C. Thomas, Springfield
Petrofsky JS, Glaser RM, Phillips CA, Lind AR, Williams C (1982) Evaluation of the amplitude and frequency components of the surface EMG as an index of muscle fatigue. Ergonomics 25(3):213–223
Ranganathan V, Siemionow V, Sahgal V, Yue G (2001) Effects of aging on hand function. J Am Geriatr Soc 49(11):1478
Reid GB, Nygren TE (1988) The subjective workload assessment technique: a scaling procedure for measuring mental workload. In: Hancock PA, Meshkati N (eds) Human mental workload. North-Holland, Amsterdam, pp 185–218
Roatta S, Kalecik N, Passatore M (2003) Sympathetic nervous system: sensory modulation and involvement in chronic pain. In: Johansson H, Windhorst U, Djupsjöbacka M, Passatore M (eds) Chronic work related myalgia, neuromuscular mechanisms behind work-related chronic muscle pain syndromes. Gävle University Press, Sweden, pp 256–276
Rowe J, Toni I, Josephs O, Frackowiak R, Passingham R (2000) The prefrontal cortex: response selection or maintenance within working memory? Science 288(5471):1656
Rudolph K, Axe M, Buchanan T, Scholz J, Snyder-Mackler L (2001) Dynamic stability in the anterior cruciate ligament deficient knee. Knee surgery, sports traumatology. Arthroscopy 9(2):62–71
Sluiter JK, Frings-Dresen MHW, Meijman TF, van der Beek AJ (2000) Reactivity and recovery from different types of work measured by catecholamines and cortisol: a systematic literature overview. Occup Environ Med 57(5):298–315. doi:10.1136/oem.57.5.298
Tachi M, Kouzaki M, Kanehisa H, Fukunaga T (2004) The influence of circulatory difference on muscle oxygenation and fatigue during intermittent static dorsiflexion. Eur J Appl Physiol 91(5):682–688. doi:10.1007/s00421-003-1024-y
van Loon EM, Masters RSW, Ring C, McIntyre DB (2001) Changes in limb stiffness under conditions of mental stress. J Motor Behav 33(2):153–164
Vøllestad NK (1997) Measurement of human muscle fatigue. J Neurosci Methods 74:219–227
Waersted M, Bjorklund RA, Westgaard RH (1991) Shoulder muscle tension induced by two VDU-based tasks of different complexity. Ergonomics 34(2):137–150
Wahlström J, Hagberg M, Johnson P, Rempel D, Svensson J (2002) Influence of time pressure and verbal provocation on physiological and psychological reactions during work with a computer mouse. Eur J Appl Physiol 87:257–263
Welford AT (1973) Stress and performance. Ergonomics 16(5):567–580
Westgaard RH (1999) Effects of physical and mental stressors on muscle pain. Scand J Work Environ Health 25(suppl 4):19–24
Westgaard RH, Bjorklund R (1987) Generation of muscle tension additional to postural muscle load. Ergonomics 30(6):911–923
Williams A, Ericsson K (2005) Perceptual-cognitive expertise in sport: some considerations when applying the expert performance approach. Hum Mov Sci 24:283–307
Yassierli, Nussbaum MA, Iridiastadi H, Wojcik LA (2007) The influence of age on isometric endurance and fatigue is muscle dependant: a study of shoulder abduction and torso extension. Ergonomics 50(1):26–45
Yerkes RM, Dodson JD (1908) The relation of strength of stimulus to rapidity of habit-formation. J Comp Neurol Psychol 18:459–482
Yoon T, Keller ML, De-Lap BS, Harkins A, Lepers R, Hunter SK (2009) Sex differences in response to cognitive stress during a fatiguing contraction. J Appl Physiol 107(5):1486
Yoshitake Y, Ue H, Miyazaki M, Moritani T (2001) Assessment of lower-back muscle fatigue using electromyography, mechanomyography, and near-infrared spectroscopy. Eur J Appl Physiol 84(3):174–179
Zijdewind I, van Duinen H, Zielman R, Lorist M (2006) Interaction between force production and cognitive performance in humans. Clin Neurophysiol 117(3):660–667
Conflict of interest
The authors declare that they have no conflict of interest.
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by Alain Martin.
Rights and permissions
About this article
Cite this article
Mehta, R.K., Agnew, M.J. Influence of mental workload on muscle endurance, fatigue, and recovery during intermittent static work. Eur J Appl Physiol 112, 2891–2902 (2012). https://doi.org/10.1007/s00421-011-2264-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00421-011-2264-x