• 대한물리의학회지
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• 제15권3호
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• pp.69-77
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• 2020

PURPOSE: The aim of this study was to measure changes in spine inclination and thoracolumbar structure and morphology according to upper-extremity movements with and without resistance in order to evaluate the spine stability in workers. METHODS: Forty-eight middle-aged male workers (mean age, 40.48 ± 6.27 years) participated in this study. Using the spine analysis system, changes in the inclination of the spine and structure as well as shape of the thoracolumbar spine were measured. For posture measurement, the postures of standing, lifting the right and left arms (shoulder joint 90° flexion), and lifting with both arms were measured in random order. In addition, variables were measured using a resistance of 3 kg for each posture. The statistical significance level was set at α = .05 for all variables. RESULTS: There were statistically significant differences between the front and back inclinations of the spine, kyphotic curve of the thoracic spine, lordotic curve of the lumbar spine, rotation changes in the thoracolumbar spine, and rotation changes in the T4 vertebra (p < .05). However, there was no significant difference in the left and right tilts of the spine. In the post-hoc analysis, rotation changes in the T4 vertebra showed a significant difference in posture when resistance was applied to the left and right sides CONCLUSION: Causes of musculoskeletal diseases include excessive thoracic spine rotation, torsion, and hyperlordosis of the lumbar spine. Therefore, it is necessary to improve the working environment in order to ensure a healthy posture and prevent musculoskeletal diseases that can reduce the ability to carry various and/or excessive loads.

• Journal of Biosystems Engineering
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• 제35권5호
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• pp.357-365
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• 2010

Workers in the agricultural industry have been exposed to many work-related musculoskeletal disorders. So, our objectives in this study were to measure and analyze worker's physiological bio-information to reduce musculoskeletal disorders in relation to agricultural works. We investigated worker's bio-information of physiological signals during the repeated lifting work such as body temperature, heart rate, blood pressure, physical activity, and heart rate variability. Moreover, we analyzed the workloads of lumbar spine during the repeated lifting work using the 3-axis acceleration and angular velocity sensors. The changes of body temperature was not significant, but the mean heart rate increased from 90/min to 116/min significantly during 30 min of repeated lifting work (p<0.05). The average worker's physical activity(energy consumption rate) was 206 kcal/70kg/h during the repeated lifting work. The workers' acute stress index was more than 80, which indicated a stressful work. Also, the maximum shear force on the disk (L5/S1) of a worker's lumbar spine in static state was 500N, and the maximum inertia moment was 139 $N{\cdot}m$ in dynamic state.

• Journal of Biosystems Engineering
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• 제38권2호
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• pp.163-170
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• 2013

Purpose: The purpose of this study is to provide analysis of physiological, biomechanical responses occurring from the operation to lifting or twist lifting task appears frequently in agricultural work. Methods: This study investigated the changes of physiological factors such as heart rate, heart rate variability (HRV) and biomechanical factors such as physical activity and kinetic analysis in the task of twisting at the waist while lifting. Results: Heart rates changed significantly with the workload. The result indicated that the workload of 2 kg was light intensity work, and the workload of 12 kg was hard intensity work. Physical activity increased as the workload increased both on wrist and waist. Besides, stress index of the worker increased with the workload. Dynamic load to herniated discs was analyzed using inertial sensor, and the angular acceleration and torque increased with the workload. The proposed measurement system can measure the recipient's physiological and physical signals in real-time and analyzed 3-dimensionally according to the variety of work load. Conclusions: The system we propose will be a new method to measure agricultural workers' multi-dimensional signals and analyze various farming tasks.

• 한국콘텐츠학회논문지
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• 제10권8호
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• pp.283-291
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• 2010

이 연구의 목적은 인체모형을 이용하여 옮기기 활동을 하는 동안 발의 배치(11자 배치와 $90^{\circ}$배치)와 옮기는 지면의 높이(휠체어 좌석과 같은 높이와 다른 높이)가 허리척추에 미치는 영향을 알아보는 것이었다. 자발적으로 실험참여에 동의한 건강한 남성 15명을 대상으로 4가지 조건에 따라 옮기기 활동을 실시 하였다. 옮기기 활동 동안 허리척추의 작업부담을 알아보기 위해, 위팔두갈래근, 척추세움근, 넙다리근의 근활성도를 표면근전도로 측정하였고, 힘판을 이용하여 수직 지면반발력을 측정하였고, L4/L5에 가해지는 압박력을 3DSSPP를 이용하여 측정하고 분석하였다. 그 결과, 오른쪽 넙다리근의 근활성도를 제외한 나머지 근육의 근활성도는 각 조건 사이 유의한 차이가 없었다. 수직 지면반발력은 각 조건 사이 유의한 차이가 있었다(p<.05). 또한 L4/L5에 가해지는 압박력은 같은 높이인 경우 발의 배치에 따라 유의한 차이가 있었다(p<.05). 따라서 옮기기 시 발을 11자로 배치하는 것보다 발을 90°로 배치하는 것이 체중이 한쪽으로 쏠리는 경향과 L4/L5 압박력을 줄이는데 도움이 되기 때문에 환자 옮기기 시 이를 적용하는 교육이 필요할 것이다.