• 산업공학
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• 제18권3호
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• pp.288-296
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• 2005

Many jobs and activities in our daily lives require squatting postures. The fore part includes housekeepers, farmers, and welders and the latter includes a wide variety of activities such as housekeeping; planting, cultivating and harvesting various agricultural products; grinding, welding, etc. It is speculated that prolonged squatting postures without any supporting stool would gradually cause musculoskeletal injuries to workers. This study is conducted to examine the proper height of stools according to the position of the working materials and to develop wearable stools for workers with squatting posture. Forty male and female subjects participated in the experiment to find the proper height of stools according to the position of the working materials. Subjects were asked to squat and work with 3 different working positions: floor level; ankle level; shank level of 3 different stool height conditions: 10cm height; 15cm height; and 20cm height. After 5 minutes of maintaining a squatting work posture while sitting on the different height stools, Likert summated rating method as well as pairwise ranking test was applied to evaluate the user preferences for provided stools under the conditions of different working positions. The results of statistical analysis show that the subjects preferred 10cm height stool for floor level, 15cm height stool for ankle level, 20cm height stool for knee level. We thus strongly recommend to use appropriate height stools in accordance with the different working positions. Moreover, a prototype wearable stool was designed such that workers with squatting posture do not need to move the stool while they are moving about. The purpose of developing wearable stool was to decrease the physical stress and hence promote worker's health who work with squatting posture.

• 한국직업건강간호학회지
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• 제26권3호
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• pp.133-141
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• 2017

Purpose: The purpose of this study was to identify the relationship between work-related characteristics and job stressors and the factors influencing musculoskeletal symptoms of the warehouse employees. Methods: The research was a cross-sectional, descriptive study. Data were collected from 319 warehouse employees who agreed to participate in the study by using self-report questionnaires. Data were analyzed using descriptive statistics, $x^2-test$, and logistic regression analysis (SPSS 18.0). Results: The overall prevalence of musculoskeletal symptoms was 37.6%. The logistic regression analysis revealed a posture that renders fatigue or pain, repetitive work, and a higher total score of job stressors as the risk factors for musculoskeletal symptoms in many body parts. Conclusion: Employers should plan to educate employees who work in warehouses about the correct working posture to prevent musculoskeletal diseases, stop repetitive work, and manage job stressors.

• 한국안전학회지
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• 제26권3호
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• pp.75-82
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• 2011

The objective of this study was to identify risk factors associated with the occurrence of musculo-skeletal symptoms of cashiers and provide suggestions for an improved workspace design. Workload and exertion of each task were measured using job analysis and posture analysis. The three most time-consuming tasks were waiting (43.8%), scanning (23.5%) and payment transaction (22.9%). It was analyzed that the workspace can be improved by applying Korean anthropometric data to the design of the desk height. The most common posture was a standing posture with neutral back, and bent lower arms and hands. Finally, it was revealed that 'scanning' and 'payment transaction' seemed more stressful than other operations. The result of the ergonomic evaluation would be a useful basis for designing an improved workspace.

• 한국직업건강간호학회지
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• 제14권1호
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• pp.5-15
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• 2005

Purpose: The purpose of this study are to identify the influencing factors on work-related musculoskeletal disorders of women workers. Method: Data were collected by questionnaires from 616 women workers from in such industries as electronics, food product, garment product and analyzed using descriptive statistics, multiple logistic regression. Result: As its result, 71.3% of female manufacturing workers had musculoskeletal symptom. When Multiple logistic regression analysis on factors relating to musculoskeletal symptoms was carried out, age, work posture, job demand, type of industry, working hour, type of work, family support were statistically significant variables. Conclusion: In conclusion, this study identifies that age, work posture, job demand, type of industry, working hour, type of work, family support are important factors affecting WMSDs.

• 산업경영시스템학회지
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• 제34권1호
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• pp.97-102
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• 2011

This study was performed to design and develop an ergonomic equipment for strawberry sorting and packing in agricultural working environments. Potential risk of work related musculo-skeletal disorders associated with farm workers performing strawberry sorting and packing was analyzed through interviews, field surveys, work measurement, and working posture evaluation. For the evaluation of working posture, we used REBA, OWAS, and RULA assessment methods to identify multi-factorial risk factors. Based on the result of comprehensive assessment, a new concept of multi-level rotating table for strawberry sorting and packing was proposed to modify awkward working postures and improve the effectiveness of the farm work. Finally, the characteristics and effectiveness of new equipment was discussed in terms of improvements in productivity, safety, and subjective ratings of farm workers. The results of analysis showed that working conditions improved significantly.

• 한국안전학회지
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• 제30권3호
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• pp.93-99
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• 2015

Economic burden of work-related musculoskeletal disorder(WMDs) is increasing. Known causes of WMDs include improper posture, repetition, load, and temperature of workplace. Among them, improper postures play an important role. A smart sensor called SensorTag is employed to estimate the trunk postures including flexion-extension, lateral bend, and the trunk rotational speeds. Measuring gravitational acceleration vector in the smart sensor along the tri-orthogonal axes offers an orientation of the object with the smart sensor attached to. The smart sensor is light in weight and has small form factor, making it an ideal wearable sensor for body posture measurement. Measured data from the smart senor is wirelessly transferred for analysis to a smartphone which has enough computing power, data storage and internet-connectivity, removing need for additional hardware for data post-processing. Based on the estimated body postures, WMDs risks can be conviently gauged by using existing WMDs risk assesment methods such as OWAS, RULA, REBA, etc.

• Safety and Health at Work
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• 제7권4호
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• pp.389-393
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• 2016

Job hazard analyses were conducted to assess exposure to musculoskeletal disorder (MSD) risk factors in seven workers of three dry-cleaning establishments. In accordance with the Washington State Ergonomics Rule, the analyses were performed in two separate steps: (1) observation and checklist approaches were made to identify a "caution zone job" in the seven workers' pressing operations across the three shops; and (2) detailed posture and motion analyses were undertaken to determine a "MSD hazard" in one worker's operation using a video technique. One "caution zone job" was identified and it was the pressing operation job in which five physical risk factors were found in the pressing operations. The detailed analyses confirmed that one "MSD hazard", i.e., awkward posture in shoulders, was prevalent in the pressing operations of the three dry-cleaning facilities. It would be desirable to reduce MSD risk factors including awkward shoulder posture in the dry-cleaning industry.

• 한국안전학회지
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• 제16권1호
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• pp.79-83
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• 2001

Posture of the upper limbs in field works is known to be an important risk factor associated with CTD(Cumulative Trauma Disorders). In particular, uncomfortable posture and highly repetitive works in shipbuilding industry(for instance, sand blasting, grinding and blast painting, etc) made workers exposed to a great risk of injuries. The purpose of this paper is to analyze recruitment pattern of the muscles according to posture(joint angle displacement) during grinding. In this study, EMG signals of pectoralis major, latissimus dorsi, and posterior deltoid muscle were measured and analyzed from FlexComp EMG solution. And subjective ratings of perceived exertion were made using Borg's CR-10 rating scale.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.603-604
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• 2006

The worker who is responsible for Airless Pump maintenance have a high possibility to suffer from WMSDs, because a height of Airless Pump workbench is too low. In this paper, I'm going to introduce a research about 1) analysis of working environment through a interview with an actual field worker, 2) Ergonomic simulation modeling of an Ariless Pump worker to suggest a advanced working environment and a working instructions. I have used a DELMIA S/W as a tool for ergonomic simulation and performed a posture & activity to analyze a RULA methodology. Applying the Digital Human Simulation to analyze working posture would be helpful to preventing WMSDs.

• 대한인간공학회지
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• 제27권1호
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• pp.53-60
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• 2008

The purpose of this study is to provide basic data, such as exerting muscle power of the lower-extremity, EMG test and pressure distribution for designing ergonomic workstation in sitting posture. The exerting muscle power of the lower-extremity was measured by PRIMUS in 4 postures of 90$^{\circ}$, 120$^{\circ}$, 150$^{\circ}$ and 180$^{\circ}$. And performed ANOVA test on Max. and Mean 100%MVC. In EMG test for surveying muscle mobiligation, 5 muscles(Rectus Femoris, Vastus Lateralis, Gastrocnemius, Soleus, Tibialis Anterior) were employed. Additional experiment in pressure distribution in sitting posture by Pliance(16$\time$16 poles), Max. pressure was measured and performed ANOVA test on the results. Concludingly, sitting posture with 120$^{\circ}$ lower-extremity is the best design criterion for ergonomic workstation in sitting posture.