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Determining Changes in Electromyography Indices when Measuring Maximum Acceptable Weight of Lift in Iranian Male Students

Document Type : Original Research

Authors

1 Department of Occupational Health, School of Public Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran

2 Department of Occupational Health, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran

3 Department of Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran

4 Department of Postgraduate Studies, Faculty of Rehabilitation, Tehran University of Medical Sciences, Int. Campus (TUMS-IC), Tehran, Iran

5 Medical Physics and Biomedical Engineering Department, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran

Abstract

Background: In spite of the increasing degree of automation in industry, manual material handling (MMH) is still performed in many occupational settings. The aim of the current study was to determine the maximum acceptable weight of lift using psychophysical and electromyography indices.Methods: This experimental study was conducted among 15 male students recruited from Tehran University of Medical Sciences. Each participant performed 18 different lifting tasks which involved three lifting frequencies, three lifting heights and two box sizes. Each set of experiments was conducted during the 20 min work period using free-style lifting technique and subjective as well as objective assessment methodologies. SPSS version 18 software was used for descriptive and analytical analyses by Friedman, Wilcoxon and Spearman correlation techniques.Results: The results demonstrated that muscle activity increased with increasing frequency, height of lift and box size (P<0.05). Meanwhile, MAWLs obtained in this study are lower than those in Snook table (P<0.05). In this study, the level of muscle activity in percent MVC in relation to the erector spine muscles in L3 and T9 regions as well as left and right abdominal external oblique muscles were at 38.89%, 27.78%, 11.11% and 5.55% in terms of muscle activity is more than 70% MVC, respectively. The results of Wilcoxon test revealed that for both small and large boxes under all conditions, significant differences were detected between the beginning and end of the test values for MPF of erector spine in L3 and T9 regions, and left and right abdominal external oblique muscles (P<0.05). The results of Spearman correlation test showed that there was a significant relation between the MAWL, RMS and MPF of the muscles in all test conditions (P<0.05).Conclusion: Based on the results of this study, it was concluded if muscle activity is more than 70% of MVC, the values of Snook tables should be revisited. Furthermore, the biomechanical perspective should receive special attention in determining the standards for MMH 

Keywords

References
  1. Yoon H, Smith JL. Psychophysical and physiological study of one-handed and two-handed combined tasks. International Journal of Industrial Ergonomics. 1999;24:49-60. doi.org/10.1016/S0169-8141(98)00087-0.
  2. Ayoub M, Selan J, Jiang B. Manual Materials Handling in Handbook of Human Factors Engineering Ed. Salvendy Gavriel, Chischester. New York, John Wiley; 1987.
  3. Snook SH, Ciriello VM. The design of manual handling tasks: revised tables of maximum acceptable weights and forces. Ergonomics. 1991;34:1197-213. doi.org/10.1080/00140139108964855. PubMed PMID: 1743178.
  4. Snook SH. The design of manual handling tasks. Ergonomics. 1978;21:963-85. doi.org/10.1080/00140137808931804. PubMed PMID: 729559.
  5. Snook SH. Psychophysical considerations in permissible loads. Ergonomics. 1985;28:327-30. doi.org/10.1080/00140138508963140. PubMed PMID: 3158515.
  6. Legg SJ, Myles WS. Maximum acceptable repetitive lifting workloads for an 8-hour work-day using psychophysical and subjective rating methods. Ergonomics. 1981;24:907-16. doi.org/10.1080/00140138108924913. PubMed PMID: 7338215.
  7. Wu SP. Maximum acceptable weight of lift by Chinese experienced male manual handlers. Appl Ergon. 1997;28:237-44. doi.org/10.1016/S0003-6870(96)00080-4. PubMed PMID: 9414362.
  8. Ciriello VM, Snook SH. A study of size, distance, height, and frequency effects on manual handling tasks. Hum Factors. 1983;25:473-83. PubMed PMID: 6667937.
  9. Ciriello VM, Snook SH, Hashemi L, Cotnam J. Distributions of manual materials handling task parameters. International Journal of Industrial Ergonomics. 1999;24:379-88. doi.org/10.1016/S0169-8141(99)00005-0.
  10. Karwowski W, Yates JW. Reliability of the psychophysical approach to manual lifting of liquids by females. Ergonomics. 1986;29:237-48. doi.org/10.1080/00140138608968262. PubMed PMID: 3956474.
  11. Snook SH, Vaillancourt DR, Ciriello VM, Webster BS. Psychophysical studies of repetitive wrist flexion and extension. Ergonomics. 1995;38:1488-507. doi.org/10.1080/00140139508925204. PubMed PMID: 7635136.
  12. Stellman JM. Encyclopaedia of occupational health and safety: International Labour Organization; 1998.
  13. Jonsson B. Kinesiology: with special reference to electromyographic kinesiology. Electroencephalogr Clin Neurophysiol Suppl. 1978;(34):417-28. PubMed PMID: 285846.
  14. Rohmert W. Problems in determining rest allowances Part 1: use of modern methods to evaluate stress and strain in static muscular work. Appl Ergon. 1973;4:91-5. doi.org/10.1016/0003-6870(73)90082-3. PubMed PMID: 15677120.
  15. Panjabi MM. The stabilizing system of the spine. Part II. Neutral zone and instability hypothesis. J Spinal Disord. 1992;5:390-6; discussion 7. doi.org/10.1097/00002517-199212000-00002. PubMed PMID: 1490035.
  16. Hodges PW, Moseley GL. Pain and motor control of the lumbopelvic region: effect and possible mechanisms. J Electromyogr Kinesiol. 2003;13:361-70. doi.org/10.1016/S1050-6411(03)00042-7. PubMed PMID: 12832166.
  17. van Dieen JH, Selen LP, Cholewicki J. Trunk muscle activation in low-back pain patients, an analysis of the literature. J Electromyogr Kinesiol. 2003;13:333-51. doi.org/10.1016/S1050-6411(03)00041-5. PubMed PMID: 12832164.
  18. Cifrek M, Medved V, Tonkovic S, Ostojic S. Surface EMG based muscle fatigue evaluation in biomechanics. Clin Biomech (Bristol, Avon). 2009;24:327-40. doi.org/10.1016/j.clinbiomech.2009.01.010. PubMed PMID: 19285766.
  19. de Looze M, Bosch T, van Dieen J. Manifestations of shoulder fatigue in prolonged activities involving low-force contractions. Ergonomics. 2009;52:428-37. doi.org/10.1080/00140130802707709. PubMed PMID: 19401894.
  20. Hostens I, Ramon H. Assessment of muscle fatigue in low level monotonous task performance during car driving. J Electromyogr Kinesiol. 2005;15:266-74. doi.org/10.1016/j.jelekin.2004.08.002. PubMed PMID: 15763673.
  21. Lin MI, Liang HW, Lin KH, Hwang YH. Electromyographical assessment on muscular fatigue--an elaboration upon repetitive typing activity. J Electromyogr Kinesiol. 2004;14:661-9. doi.org/10.1016/j.jelekin.2004.03.004. PubMed PMID: 15491841.
  22. Tucker K, Falla D, Graven-Nielsen T, Farina D. Electromyographic mapping of the erector spinae muscle with varying load and during sustained contraction. J Electromyogr Kinesiol. 2009;19:373-9. doi.org/10.1016/j.jelekin.2007.10.003. PubMed PMID: 18061480.
  23. Kumar S. The effect of sustained spinal load on intra-abdominal pressure and EMG characteristics of trunk muscles. Ergonomics. 1997;40:1312-34. doi.org/10.1080/001401397187397. PubMed PMID: 9416014.
  24. Arjmand N, Shirazi-Adl A. Model and in vivo studies on human trunk load partitioning and stability in isometric forward flexions. J Biomech. 2006;39:510-21. doi.org/10.1016/j.jbiomech.2004.11.030. PubMed PMID: 16389091.
  25. Abdoli EM, Agnew MJ, Stevenson JM. An on-body personal lift augmentation device (PLAD) reduces EMG amplitude of erector spinae during lifting tasks. Clin Biomech (Bristol, Avon). 2006;21:456-65. doi.org/10.1016/j.clinbiomech.2005.12.021. PubMed PMID: 16494978.
  26. Chan S. The use of EMG for load prediction during manual lifting. 2007.
Journal of Biomedical Physics and Engineering
Volume 8, Issue 1 - Serial Number 1
27
March 2018
Pages 73-86
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