Strength Training Improves Fatigue Resistance and Self-Rated Health in Workers with Chronic Pain: A Randomized Controlled Trial

Emil Sundstrup, Markus Due Jakobsen, Mikkel Brandt, Kenneth Jay, Per Aagaard, Lars Louis Andersen, Emil Sundstrup, Markus Due Jakobsen, Mikkel Brandt, Kenneth Jay, Per Aagaard, Lars Louis Andersen

Abstract

Chronic musculoskeletal pain is widespread in the working population and leads to muscular fatigue, reduced work capacity, and fear of movement. While ergonomic intervention is the traditional approach to the problem, physical exercise may be an alternative strategy. This secondary analysis of a randomized controlled trial investigates the effect of strength training on muscular fatigue resistance and self-rated health among workers with chronic pain. Sixty-six slaughterhouse workers with chronic upper limb pain and work disability were randomly allocated to 10 weeks of strength training or usual care ergonomic training (control). At baseline and follow-up, participants performed a handgrip muscular fatigue test (time above 50% of maximal voluntary contraction force) with simultaneous recording of electromyography. Additionally, participants replied to a questionnaire regarding self-rated health and pain. Time to fatigue, muscle strength, hand/wrist pain, and self-rated health improved significantly more following strength training than usual care (all P < 0.05). Time to fatigue increased by 97% following strength training and this change was correlated to the reduction in fear avoidance (Spearman's rho = -0.40; P = 0.01). In conclusion, specific strength training improves muscular fatigue resistance and self-rated health and reduces pain of the hand/wrist in manual workers with chronic upper limb pain. This trial is registered with ClinicalTrials.gov NCT01671267.

Figures

Figure 1
Figure 1
Participant flow. Missing data (i.e., participants with no data on fatigue test at baseline and follow-up) was present from 6 and 2 participants in the strength training and in the usual care ergonomic group, respectively. Therefore, 27 and 31 participants were included in the analyses of the fatigue test from the strength training group and usual care ergonomic group, respectively.
Figure 2
Figure 2
A representative illustration of the force output during the handgrip fatigue test in a strength trained person at follow-up. Individuals were to press as hard as possible throughout the entire fatigue test, and when the force output decreased to below 50% of MVC the test was finished. Peak force (normalized to MVC), start time (To), and time at fatigue (Tfatigue) are illustrated on the figure.
Figure 3
Figure 3
Radar-chart summarizing the interventional changes (% change) for the main variables following strength training (blue covered area) and ergonomic usual care (red covered area). The black broken line represents no change. Variables arranged clockwise: (1) pain intensity of the hand/wrist, (2) fear avoidance, (3) self-rated health, (4) handgrip strength, (5) extensor EMG during handgrip MVC, (6) flexor EMG during handgrip MVC, (7) time to fatigue, (8) extensor EMG during fatigue test, (9) flexor EMG during fatigue test. P < 0.05.

References

    1. Bernard B. Musculoskeletal Disorders and Workplace Factors: A Critical Review of Epidemiologic Evidence for Work-Related Musculoskeletal Disorders of the Neck, Upper Extremity, and Low Back. US Department of Health and Human Services Public Health Services, Centers for Disease Control and Prevention, The National Institute for Occupational Safety and Health; 1997.
    1. Sommerich C. M., McGlothlin J. D., Marras W. S. Occupational risk factors associated with soft tissue disorders of the shoulder: a review of recent investigations in the literature. Ergonomics. 1993;36(6):697–717. doi: 10.1080/00140139308967931.
    1. Bosch T., Mathiassen S. E., Visser B., de Looze M. D., van Dieën J. V. The effect of work pace on workload, motor variability and fatigue during simulated light assembly work. Ergonomics. 2011;54(2):154–168. doi: 10.1080/00140139.2010.538723.
    1. Frost P., Andersen J. H., Nielsen V. K. Occurrence of carpal tunnel syndrome among slaughterhouse workers. Scandinavian Journal of Work, Environment and Health. 1998;24(4):285–292. doi: 10.5271/sjweh.322.
    1. Viikari Juntura E. Neck and upper limb disorders among slaughterhouse workers. An epidemiologic and clinical study. Scandinavian Journal of Work, Environment and Health. 1983;9(3):283–290. doi: 10.5271/sjweh.2416.
    1. Windt D. A. W. M. V. D., Thomas E., Pope D. P., et al. Occupational risk factors for shoulder pain: a systematic review. Occupational and Environmental Medicine. 2000;57(7):433–442. doi: 10.1136/oem.57.7.433.
    1. Sundstrup E., Jakobsen M. D., Jay K., Brandt M., Andersen L. L. High intensity physical exercise and pain in the neck and upper limb among slaughterhouse workers: Cross-Sectional Study. BioMed Research International. 2014;2014:5. doi: 10.1155/2014/218546.218546
    1. Bültmann U., Kant I., Kasl S. V., Beurskens A. J. H. M., van den Brandt P. A. Fatigue and psychological distress in the working population: psychometrics, prevalence, and correlates. Journal of Psychosomatic Research. 2002;52(6):445–452. doi: 10.1016/s0022-3999(01)00228-8.
    1. Janssen N., Kant I. J., Swaen G. M. H., Janssen P. P. M., Schröer C. A. P. Fatigue as a predictor of sickness absence: results from the Maastricht cohort study on fatigue at work. Occupational and Environmental Medicine. 2003;60(1):i71–i76. doi: 10.1136/oem.60.suppl_1.i71.
    1. Van Amelsvoort L. G. P. M., Kant I. J., Beurskens A. J. H. M., Schröer C. A. P., Swaen G. M. H. Fatigue as a predictor of work disability. Occupational and Environmental Medicine. 2002;59(10):712–713. doi: 10.1136/oem.59.10.712.
    1. Enoka R. M., Stuart D. G. Neurobiology of muscle fatigue. Journal of Applied Physiology. 1992;72(5):1631–1648. doi: 10.1063/1.351680.
    1. Bigland-Ritchie B., Donovan E. F., Roussos C. S. Conduction velocity and EMG power spectrum changes in fatigue of sustained maximal efforts. Journal of Applied Physiology Respiratory Environmental and Exercise Physiology. 1981;51(5):1300–1305.
    1. Hunter S. K., Duchateau J., Enoka R. M. Muscle fatigue and the mechanisms of task failure. Exercise and Sport Sciences Reviews. 2004;32(2):44–49. doi: 10.1097/00003677-200404000-00002.
    1. Hansson G.-A., Stromberg U., Larsson B., Ohlsson K., Balogh I., Moritz U. Electromyographic fatigue in neck/shoulder muscles and endurance in women with repetitive work. Ergonomics. 1992;35(11):1341–1352. doi: 10.1080/00140139208967397.
    1. Andersen L. L., Andersen C. H., Skotte J. H., et al. High-intensity strength training improves function of chronically painful muscles: Case-Control and RCT Studies. BioMed Research International. 2014;2014:11. doi: 10.1155/2014/187324.187324
    1. Andersen L. L., Andersen J. L., Suetta C., Kjær M., Søgaard K., Sjøgaard G. Effect of contrasting physical exercise interventions on rapid force capacity of chronically painful muscles. Journal of Applied Physiology. 2009;107(5):1413–1419. doi: 10.1152/japplphysiol.00555.2009.
    1. Reneman M. F., Schiphorts Preuper H. R., Kleen M., Geertzen J. H. B., Dijkstra P. U. Are pain intensity and pain related fear related to functional capacity evaluation performances of patients with chronic low back pain? Journal of Occupational Rehabilitation. 2007;17(2):247–258. doi: 10.1007/s10926-007-9078-z.
    1. Pedersen B. K., Saltin B. Evidence for prescribing exercise as therapy in chronic disease. Scandinavian Journal of Medicine and Science in Sports. 2006;16(supplement 1):3–63. doi: 10.1111/j.1600-0838.2006.00520.x.
    1. Andersen L. L., Saervoll C. A., Mortensen O. S., Poulsen O. M., Hannerz H., Zebis M. K. Effectiveness of small daily amounts of progressive resistance training for frequent neck/shoulder pain: randomised controlled trial. Pain. 2011;152(2):440–446. doi: 10.1016/j.pain.2010.11.016.
    1. Sundstrup E., Jakobsen M. D., Andersen C. H., et al. Effect of two contrasting interventions on upper limb chronic pain and disability: a randomized controlled trial. Pain Physician. 2014;17(2):145–154.
    1. Sundstrup E., Jakobsen M. D., Andersen C. H., et al. Participatory ergonomic intervention versus strength training on chronic pain and work disability in slaughterhouse workers: study protocol for a single-blind, randomized controlled trial. BMC Musculoskeletal Disorders. 2013;14, article 67 doi: 10.1186/1471-2474-14-67.
    1. American College of Sports Medicine. American college of sports medicine position stand. progression models in resistance training for healthy adults. Medicine & Science in Sports & Exercise. 2009;41(3):687–708.
    1. Pincus T., Bergman M., Sokka T., Roth J., Swearingen C., Yazici Y. Visual analog scales in formats other than a 10 centimeter horizontal line to assess pain and other clinical data. Journal of Rheumatology. 2008;35(8):1550–1558.
    1. Kuorinka I., Jonsson B., Kilbom A., et al. Standardised Nordic questionnaires for the analysis of musculoskeletal symptoms. Applied Ergonomics. 1987;18(3):233–237. doi: 10.1016/0003-6870(87)90010-x.
    1. Tan H., Pogosyan A., Anzak A., et al. Frequency specific activity in subthalamic nucleus correlates with hand bradykinesia in Parkinson's disease. Experimental Neurology. 2013;240(1):122–129. doi: 10.1016/j.expneurol.2012.11.011.
    1. Jakobsen M. D., Sundstrup E., Andersen C. H., et al. Muscle activity during knee-extension strengthening exercise performed with elastic tubing and isotonic resistance. International Journal of Sports Physical Therapy. 2012;7(6):606–616.
    1. Ware J. E., Sherbourne C. D. The MOS 36-item short-form health survey (Sf-36): I. Conceptual framework and item selection. Medical Care. 1992;30(6):473–483. doi: 10.1097/00005650-199206000-00002.
    1. Sundstrup E., Jakobsen M. D., Brandt M., Jay K., Aagaard P., Andersen L. L. Associations between biopsychosocial factors and chronic upper limb pain among slaughterhouse workers: cross sectional study. BMC Musculoskeletal Disorders. 2016;17(1, article 104) doi: 10.1186/s12891-016-0953-7.
    1. Dobson J. L., McMillan J., Li L. Benefits of exercise intervention in reducing neuropathic pain. Frontiers in Cellular Neuroscience. 2014;8(1, article 102) doi: 10.3389/fncel.2014.00102.
    1. Mathur N., Pedersen B. K. Exercise as a mean to control low-grade systemic inflammation. Mediators of Inflammation. 2008;2008:6. doi: 10.1155/2008/109502.109502
    1. Hopps E., Canino B., Caimi G. Effects of exercise on inflammation markers in type 2 diabetic subjects. Acta Diabetologica. 2011;48(3):183–189. doi: 10.1007/s00592-011-0278-9.
    1. Pedersen B. K., Brandt C. The role of exercise-induced myokines in muscle homeostasis and the defense against chronic diseases. Journal of Biomedicine and Biotechnology. 2010;2010:6. doi: 10.1155/2010/520258.520258
    1. Moldoveanu A. I., Shephard R. J., Shek P. N. The cytokine response to physical activity and training. Sports Medicine. 2001;31(2):115–144. doi: 10.2165/00007256-200131020-00004.
    1. Larsson B., Björk J., Kadi F., Lindman R., Gerdle B. Blood supply and oxidative metabolism in muscle biopsies of female cleaners with and without myalgia. Clinical Journal of Pain. 2004;20(6):440–446. doi: 10.1097/00002508-200411000-00009.
    1. Sjøgaard G., Rosendal L., Kristiansen J., et al. Muscle oxygenation and glycolysis in females with trapezius myalgia during stress and repetitive work using microdialysis and NIRS. European Journal of Applied Physiology. 2010;108(4):657–669. doi: 10.1007/s00421-009-1268-2.
    1. Sjøgaard G., Zebis M. K., Kiilerich K., Saltin B., Pilegaard H. Exercise training and work task induced metabolic and stress-related mrna and protein responses in myalgic muscles. BioMed Research International. 2013;2013:12. doi: 10.1155/2013/984523.984523
    1. Andersen J. L., Aagaard P. Myosin heavy chain IIX overshoot in human skeletal muscle. Muscle and Nerve. 2000;23(7):1095–1104.
    1. Farup J., Sørensen H., Kjølhede T. Similar changes in muscle fiber phenotype with differentiated consequences for rate of force development: endurance versus resistance training. Human Movement Science. 2014;34(1):109–119. doi: 10.1016/j.humov.2014.01.005.
    1. Aagaard P., Andersen J. L. Effects of strength training on endurance capacity in top-level endurance athletes. Scandinavian Journal of Medicine and Science in Sports. 2010;20(2):39–47. doi: 10.1111/j.1600-0838.2010.01197.x.
    1. Takala E.-P., Viikari-Juntura E., Moneta G. B., Saarenmaa K., Kaivanto K. Seasonal variation in neck and shoulder symptoms. Scandinavian Journal of Work, Environment and Health. 1992;18(4):257–261. doi: 10.5271/sjweh.1580.
    1. Persson R., Österberg K., Garde A. H., Hansen Å. M., Ørbæk P., Karlson B. Seasonal variation in self-reported arousal and subjective health complaints. Psychology, Health and Medicine. 2010;15(4):434–444. doi: 10.1080/13548506.2010.482140.
    1. Sundstrup E., Jakobsen M. D., Brandt M., et al. Workplace strength training prevents deterioration of work ability among workers with chronic pain and work disability: a randomized controlled trial. Scandinavian Journal of Work, Environment and Health. 2014;40(3):244–251. doi: 10.5271/sjweh.3419.
    1. Vlaeyen J. W. S., Linton S. J. Fear-avoidance and its consequences in chronic musculoskeletal pain: a state of the art. Pain. 2000;85(3):317–332. doi: 10.1016/s0304-3959(99)00242-0.
    1. Idler E. L., Benyamini Y. Self-rated health and mortality: a review of twenty-seven community studies. Journal of Health and Social Behavior. 1997;38(1):21–37. doi: 10.2307/2955359.
    1. Mora P. A., Orsak G., DiBonaventura M. D., Leventhal E. A. Why do comparative assessments predict health? The role of self-assessed health in the formation of comparative health judgments. Health Psychology. 2013;32(11):1175–1178. doi: 10.1037/a0032044.
    1. Mäntyselkä P. T., Turunen J. H. O., Ahonen R. S., Kumpusalo E. A. Chronic pain and poor self-rated Health. Journal of the American Medical Association. 2003;290(18):2435–2442. doi: 10.1001/jama.290.18.2435.
    1. Elliott A. M., Smith B. H., Hannaford P. C., Smith W. C., Chambers W. A. The course of chronic pain in the community: results of a 4-year follow-up study. Pain. 2002;99(1-2):299–307. doi: 10.1016/s0304-3959(02)00138-0.

Source: PubMed

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