비대칭무게중심을 지닌 물체 들기 작업시 허리부위 등근육 부하 및 피로 분석
The Analysis of Low Back Loading and Muscle Fatigue while Lifting an Asymmetric Load
1
조회
0
다운로드
8
인용
0
참고문헌
키워드
초록
This study is aimed to show that an asymmetric load in the frontal plane leads to an increase in low back loading and fatigue in comparison with a symmetric load when workers lift an external weight by investigating previous studies and verifying the phenomenon with an experiment. Ten male subjects are required to lift and hold an given external load at 70cm height during 50sec, then the EMG amplitude and median frequency on bilateral low back muscle groups (Longissimus, Iliocostalis, and Multifidus)are recorded and analyzed. Independent variables are two-level load weight (13kg, 20kg) and three-level LCG (Center, 6.5cm to the right, and 13cm to the right), and dependent variables are EMG amplitude average, difference, and Fatigue Index (FI). Results show that load weight increases significantly amplitude average and FI, but LCG does significantly amplitude difference and FI significanlty (P-value < 0.05). Also the correlation coefficient between amplitude difference and FI is over 0.99. These implies that trunk loading should be explained by not EMG amplitude but muscle fatigue aspect since the association between an external load and amplitude is linear, but the relationship between an external load and median frequency as muscle fatigue index is almost exponential.
Abstract
This study is aimed to show that an asymmetric load in the frontal plane leads to an increase in low back loading and fatigue in comparison with a symmetric load when workers lift an external weight by investigating previous studies and verifying the phenomenon with an experiment. Ten male subjects are required to lift and hold an given external load at 70cm height during 50sec, then the EMG amplitude and median frequency on bilateral low back muscle groups (Longissimus, Iliocostalis, and Multifidus)are recorded and analyzed. Independent variables are two-level load weight (13kg, 20kg) and three-level LCG (Center, 6.5cm to the right, and 13cm to the right), and dependent variables are EMG amplitude average, difference, and Fatigue Index (FI). Results show that load weight increases significantly amplitude average and FI, but LCG does significantly amplitude difference and FI significanlty (P-value < 0.05). Also the correlation coefficient between amplitude difference and FI is over 0.99. These implies that trunk loading should be explained by not EMG amplitude but muscle fatigue aspect since the association between an external load and amplitude is linear, but the relationship between an external load and median frequency as muscle fatigue index is almost exponential.
참고문헌 (23)
- 김홍기, "한 손 들기 작업과 양 손 들기 작업의 근력 능력 비교 연구", 대한인간공학회지, 26(2), pp.35~44 (2007), 대한인간공학회
- 2010년도 산업재해 현황분석, "노동부", ~ (2011)
- 송영희, "관절각도에 따른 근 피로도와 등척성 훈련 전이효과", 대한인간공학회지, 25(4), pp.93~101 (2006), 대한인간공학회
- 여민우, "좌식 작업에 있어서 슬관절 각도 변화에 따른 하지 근력 및 압력분포 분석에 관한 연구", 대한인간공학회지, 27(1), pp.53~60 (2008), 대한인간공학회
- 원종임, "등속성 운동시 근전도 주파수 분석에서 얻은 피로 지수의 특성", 박사, pp.2001
- Butter, D., "The influence of load knowledge on lifting technique", Ergonomics, 36(12), pp.1489~1493 (1993)
- Chaffin, D. B., "Occupational Biomechanics, 4th Edition", pp.131~136 (2006), John Wiley and Sons, Inc.
- Commissaris, D. A. C. M., "Load knowledge affects low back loading and control of balance in lifting tasks", Ergonomics, 40(5), pp.559~575 (1997)
- Coorevits, P. L. M., "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, pp.444~451 (2005)
- Cram, J. R., "EMG scanning in the diagonosis of chronic pain", Biofeedback and self-regulation, 8(2), pp.223~241 (1983)
- Dolan, P., "The relationship between EMG activity and extensor moment generation in the elector spinae muscles during bending and lifting activities", Journal of Biomechanics, 26, pp.13~522 (1993)
- Mannion, A. F., "The use of surface EMG power spectral analysis in the evaluation of back muscle function", Journal of Rehabilitation Research and Development, 34(4), pp.427~439 (1997)
- Mannion, A. F., "The effects of muscle length and force output on the EMG power spectrum of the elector spinae", J. Electromyogr. Kinesiol, 6(3), pp.159~168 (1996)
- Marras, W. S., "Trunk muscle activities during asymmetric twisting motions", Journal of Electromyography and Kinesiology, 8, pp.247~256 (1998)
- Mital, A., "Psychophysical and physiological responses to lifting symmetrical and asymmetrical loads symmetrically and asymmetrically", Ergonomics, 29(10), pp.1263~1272 (1986)
- Ng, J. K. -F., "Electromyography amplitude and fatigue changes in the iliocostalis lumborum and multifidus muscles during a trunk holding test", Physical Therapy, 77(9), pp.954~961 (1997)
- Noone, G., "Asymmetrical loads and lateral bending of the human spine", Med.&Bio.Eng.Comput., 21, pp.131~136 (1997)
- Nordin, M., "Musculoskeletal Disorders in the Workplace, 2nd Edition", pp.87~ (1997), Mosby-Year Book, Inc.
- Reid, D. A., "Factors contributing to low back pain in ro", Br. j. Sports Med., 34(5), pp.321~322 (2000)
- Roy, S. H., "Fatigue, recovery, and low back pain in varsity rowers", Medicine and Science in Sports and Exercise, 22(4), pp.463~469 (1990)
- Seroussi, R. E., "The relationship between trunk muscle electromyography and lifting moments in the sagittal and frontal planes", Biomechanics, 20(2), pp.135~146 (1987)
- 신관섭, "Influence of knee angle and individual flexibility on the flexion-relaxation response of the low back musculature", JOURNAL OF ELECTROMYOGRAPHY AND KINESIOLOGY, 14(4), pp.485~494, ELSEVIER SCI LTD
- Winter, D. A., "Biomechanics and motor control of human movement, 4th Edition", pp.269~277 (2009), John Wiley and Sons, Inc.