Journal of Korean Society of Industrial and Systems Engineering (산업경영시스템학회지)

Society of Korea Industrial and System Engineering (한국산업경영시스템학회)
권호 표지

Strategical Postures for Relieving EMG Amplitude Discrepancy on Bilateral Low Back Muscles and Total Low Back Muscle Fatigue while Lifting Asymmetric Load Dynamically

비대칭무게중심 물체의 동적 들기 작업시 좌.우 허리 근육의 EMG 진폭차이와 피로를 줄이기 위한 자세 연구

  • Kim, Sun-Uk (Department of Industrial Engineering, Dankook University) ;
  • Han, Seung-Jo (Department of Industrial Engineering, Dankook University)
  • 김선욱 (단국대학교 공학대학 산업공학과) ;
  • 한승조 (단국대학교 공학대학 산업공학과)
  • Received : 2012.06.21
  • Accepted : 2012.07.16
  • Published : 2012.09.30
Download PDF
⟨ Previous Next ⟩

Abstract

The purpose of this paper is to suggest the strategical lifting postures able to alleviate imbalanced EMG amplitude leading to an increase in low back muscle fatigue while lifting asymmetric load dynamically. Eleven male subjects are required to lift symmetrically an external load with 15.8kg and load center of gravity (LCG) deviated 10cm to the right from the floor to the waist height at the speed of about 25cm/sec. The EMG amplitudes on bilateral low back muscles (Longissimus, Iliocostalis, and Multifidus) are recorded during 2sec and analyzed. Independent variables are trunk postures (No bending vs. Bending to the LCG) and feet placements (Parallel vs. Right foot in front of the other vs. Right foot behind the other). Dependent variables are EMG amplitude average on six muscles and the EMG amplitude difference between right and left muscle group. Results indicate the phenomenon showing an amplitude increase in the left muscle group is equal to an decrease in the right one is observed in dynamic as well as static lifts, bending the trunk to the LCG increases amplitude discrepancy more than no trunk bending, and the amplitude discrepancy in one foot ipsilateral to LCG in front of the other foot is lowest among other foot postures. As bilateral EMG amplitude discrepancy increases total low back muscle fatigue, the strategical combination of no trunk bending and one foot close to LCG in front of the other is recommended for preventing elevated incidence of low back pain (LBP).

Keywords

References

  1. 김증호; "산업현장 근로자의 근골격계 질환 예방 제도 및 사업추진 전략", 대한운동학회 2012년 산업안전 세미나 발표논문집, 서울교육대학교, 서울, 9-30, 2012.
  2. 김홍기; "한 손 들기 작업과 양 손 들기 작업의 근력 능력 비교 연구", 대한인간공학회지, 26(3) : 35-44, 2007.
  3. 노동부; "2010년도 산업재해 현황분석", 2011.
  4. 송영희, 권오윤; "관절각도에 따른 근 피로도와 등척성 훈련 전이효과", 대한인간공학회지, 25(4) : 93-101, 2006.
  5. 여민우, 이동춘; "좌식 작업에 있어서 슬관절 각도 변화에 따른 하지 근력 및 압력분포 분서에 관한 연구", 대한인간공학회지, 27(1) : 53-60, 2008.
  6. 장성록, 김용수, 이관석, 김유창, 배동철; "근골격계 질환의 제도적 관리에 관한 연구", 한국안전학회지, 18(3) : 149-153, 2003.
  7. 한승조, 김선욱; "비대칭무게중심의 물체취급이 허리에 미치는 영향에 대한 모델 연구", 한국산업경영시스템학회 2012년도 춘계학술대회 발표논문집, 창원 대학교, 창원, 29-34, 2012.
  8. 한승조, 김선욱; "비대칭 무게 중심을 지닌 물체 들기 작업시 허리부위 등근육 부하 및 피로도 분석", 한국산업경영시스템학회지, 35(2) : 30-36, 2012.
  9. Bigland, B. and Lippold, O. C. J.; "The relation between force, velocity and integrated electrical activity in human muscles," Journal of Physiology, 123 : 214-224, 1954.
  10. Butter, D., Anderson, G. B. J., Trafimow, J., Schipplein, O. D., and Andriacchi, T. P.; "The influence of load knowledge on lifting technique," Ergonomics, 36(12) : 1489-1493, 1993. https://doi.org/10.1080/00140139308968016
  11. Chaffin, D. B., Andersson, G. B. J., and Martin, B. J.; Occupational Biomechanics, 4th Edition, John Wiley and Sons, Inc., New Jersey : 131-136, 2006.
  12. Commissaris, D. A. C. M. and Toussaint, H. M.; "Load knowledge affects low back loading and control of balance in lifting tasks," Ergonomics, 40(5) : 559-575, 1997. https://doi.org/10.1080/001401397188035
  13. Coorevits, P. L. M., Danneels, L. A., Ramon, R. Van Audekercke., Cambier, D. C., and Vanderstaeten, G. G.; "Statistical modeling of fatigue-related electromyographic median frequency characteristics of back and hip muscles during a standardized isometric back extension test," Journal of Electrophyography and Kinesiology, 15 : 444-451, 2005. https://doi.org/10.1016/j.jelekin.2005.02.002
  14. de Loose, M. P., Toussaint, H. M., van Dieen, J. H., and Kemper, H. C. G.; "Joint moments and muscle activity in the lower extremities and lower back in lifting and lowering tasks," Journal of Biomechanics, 26(9) : 1067-1076, 1993. https://doi.org/10.1016/S0021-9290(05)80006-5
  15. Dolan, P. and Adams, A.; "The relationship between EMG activity and extensor moment generation in the elector spinae muscles during bending and lifting activities," Journal of Biomechanics, 26 : 513-522, 1993. https://doi.org/10.1016/0021-9290(93)90013-5
  16. Faber, G. S., Kingma, I., Baker, A. J. M., and van Dieen, J. H.; "Low-back loading in lifting two loads beside the body compared to lifting one load in front of the body," Journal of Biomechanics, 42 : 35-41, 2009. https://doi.org/10.1016/j.jbiomech.2008.10.013
  17. McGill, S.; "The biomechanics of low back pain : implications on current practice in industrial and the clinic," Biomechanics, 30(5) : 465-475, 1997. https://doi.org/10.1016/S0021-9290(96)00172-8
  18. McKean, C. M. and Potvin, J. R.; "Effects of a simulated industiral bin on lifting and lowering posture and trunk extensor muscle activity," International Journal of Industrial Ergonomics, 28 : 1-15, 2001. https://doi.org/10.1016/S0169-8141(00)00060-3
  19. Nordin, M., Andersson, G. B. J., and Pope, M. H.; Musculoskeletal Disorders in the Workplace, 2nd Edition, Mosby-Year Book, Inc., Missouri, 87, 1997.
  20. Roy, S. H., De Luca, C. J., Snyder-Mackler, L. Emley, M. S., Crenshaw, R. L., and Lyons, J. P.; "Fatigue, recovery, and low back pain in varsity rowers," Medicine and Science in Sports and Exercise, 22(4) : 463-469, 1990.