• Safety and Health at Work
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• v.3 no.2
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• pp.146-153
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• 2012

Objectives: The introduction of computerized numeric control (CNC) technology in manufacturing industries has revolutionized the production process, but there are some health and safety problems associated with these machines. The present study aimed to investigate the extent of postural discomfort in CNC machine operators, and the relationship of this discomfort to the display and control panel height, with a view to validate the anthropometric recommendation for the location of the display and control panel in CNC machines. Methods: The postural discomforts associated with CNC machines were studied in 122 male operators using Corlett and Bishop's body part discomfort mapping, subject information, and discomfort level at various time intervals from starting to end of a shift. This information was collected using a questionnaire. Statistical analysis was carried out using ANOVA. Results: Neck discomfort due to the positioning of the machine displays, and shoulder and arm discomfort due to the positioning of controls were identified as common health issues in the operators of these machines. The study revealed that 45.9% of machine operators reported discomfort in the lower back, 41.8% in the neck, 22.1% in the upper-back, 53.3% in the shoulder and arm, and 21.3% of the operators reported discomfort in the leg. Conclusion: Discomfort increased with the progress of the day and was highest at the end of a shift; subject age had no effect on patient tendency to experience discomfort levels.

• Journal of Korean Biological Nursing Science
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• v.12 no.2
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• pp.81-88
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• 2010

Purpose: The purpose of this study was to compare effects of intravenous fluid warming and forced-air warming on perioperative body temperature, Blood Pressure, Pulse and thermal discomfort after gastrectomy under general anesthesia. Methods: Data collection was performed from October, 2009 to February, 2010. The intravenous fluid warming group (27) was warmed through an IV line by an Animec set to $37^{\circ}C$. The forced-air warming group (27) was warmed by Bair Hugger System. The warming continued from induction of general anesthesia to two hours after completion of surgery. The data was analyzed by t-test, $X^2$, repeated measures ANOVA using SPSS/WIN 17.0. Results: There was a significant difference of body temperature and thermal discomfort between the intravenous fluid warming group and the forced-air warming group. Conclusion: We need to explore the effects combination of the intravenous fluid warming and the forced-air warming, and other warming therapy and the efficiency of modalities with regards to cost benefit is also needed.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.3
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• pp.192-197
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• 2013

In this study, it is investigated the relationship between sitting discomfort and major design variables of lumber support, such as prominence, height and width through volunteer tests. Korean $50^{th}$ percentile males and American $50^{th}$ percentile males are recruited among 36 to 45 years old peoples who have driving experiences and have no back pain during the past 12 months. Subject ratings are asked by changing design variables randomly. Body pressure and lumber position changes are also measured as object measures. And correlation among subject ratings, object measures and three design variables are analyzed using statistical analysis. As a result, it is revealed that prominence is the most dominant factor that correlates to the discomfort strongly for both-Koreans and Americans and contribution of other two variables are very low.

• Journal of the Ergonomics Society of Korea
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• v.30 no.2
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• pp.297-302
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• 2011

Many WMSDs(work-related-musculoskeletal disorders) have been reported in diverse industries and have also attracted much attention in recent years. Neck-related MSD is generally known as one of common WMSDs, especially it happens to workers who are working at the automobile assembly plants and/or shipyards. The awkward posture is considered as a main cause of neck-related MSDs. A neck supporter was developed to prevent neck-related MSDs, and 10 males were recruited to evaluate the newly developed neck supporter by measuring subjective discomfort ratings of whole body, shoulder, neck and neck-muscle activities. Muscle activities from four neck muscle groups(left/right sternocleidomastoid and upper/middle trapezius) were measured while simulating an automobile assembly task. Results showed that the neck supporter help to significantly improve subjective discomfort for whole-body, shoulder as well as neck body parts. The analyses of muscular activities also showed that the activities of left/right sternocleidomastoid muscles were statistically decreased with the neck supporter in this study. The muscle activities of upper/middle trapezius in case of wearing the neck supporter were not significantly different with the muscle activities in case of no-wearing the neck supporter. Overall findings verified that the neck supporter might help to prevent neck-related MSDs based on the current study.

• Safety and Health at Work
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• v.8 no.2
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• pp.212-219
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• 2017

Background: Low back pain (LBP) is a major problem for office workers. Individuals adopting poor postures during prolonged sitting have a considerably increased risk of experiencing LBP. This study aimed to investigate seat pressure distribution characteristics, i.e., average pressure, peak pressure ratio, frequency of postural shift, and body perceived discomfort (BPD), during 1 hour of sitting among office workers with and without chronic LBP. Methods: Forty-six participants (chronic LBP = 23, control = 23) typed a standardized text passage at a computer work station for an hour. A seat pressure mat device was used to collect the seat pressure distribution data. Body discomfort was assessed using the Body Perceived Discomfort scale. Results: Office workers with chronic LBP sat significantly more asymmetrically than their healthy counterparts. During 1-hour sitting, all workers appeared to assume slumped sitting postures after 20 minutes of sitting. Healthy workers had significantly more frequent postural shifts than chronic LBP workers during prolonged sitting. Conclusion: Different sitting characteristics between healthy and chronic LBP participants during 1 hour of sitting were found, including symmetry of sitting posture and frequency of postural shift. Further research should examine the roles of these sitting characteristics on the development of LBP.

• Journal of the Ergonomics Society of Korea
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• v.33 no.6
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• pp.565-575
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• 2014

Objective: The aim of this study is to evaluate the effect of weight of load and time on the physical workload of repetitive upper-limb tasks with handling light weight loads using EMG and perceived discomfort, and to investigate the relationship between EMG and perceived discomfort for those repetitive tasks of moving light weight loads. Background: Repetitive upper-limb motion is known as one of the main risk factors of musculoskeletal disorders, and a lot of repetitive tasks are carried out while handling light weight loads in the industry. In evaluating the workload of repetitive tasks handling light weight loads, EMG and perceived discomfort can be used, though their relationship in those work conditions are not much investigated. Method: A laboratory experiment with 18 healthy males were conducted to record EMG signals from 5 muscle sites of the right arm and shoulder and rate perceived discomforts for the body parts and the whole body while carrying out repetitive materials-handling tasks for 52min. The subjects were divided into 3 groups which handled the loads of 1kg, 2kg and 3kg, respectively. ANOVAs were conducted to analyze the effects of the weight and time on RMS of EMG amplitude (normalized RMS: NRMS), median frequency of power spectrum of EMG (normalized MDF: NMDF) and perceived discomfort. The correlations between NRMS and NMDF and perceived discomfort were also analyzed. Results: Statistically significant muscular fatigue effects were not found from NRMS and NMDF in most muscles, while there were significant increases of discomfort as the task time elapsed. It was shown that there were an increasing trend of the muscular activity as the weight of load increased and a decreasing trend of median frequency of EMG of upper and lower arms as time elapsed. It was found that there were significant negative correlations between NMDFs from the lower arm and discomfort ratings, though the relationships were weak. Conclusion: It can be concluded that the working conditions adopted in this study were not enough to induce muscular fatigue, while there was significant increase in perceived discomfort. A further study is necessary to integrate the objective and subjective measures for more reliable and sensitive evaluation of workload of repetitive tasks of handling light weight loads. Application: This study can be used as a basic study for the evaluation of workload of repetitive tasks handling light weight loads.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.17 no.2
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• pp.220-230
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• 2010

Purpose: This study was done to identify differences in three groups of operative patients (Forced Air Warming, Electrical Blanketrol, Control) for discomfort and pattern of body temperature during surgery and post operatively. Methods: The sample consisted of 3 randomized 3 groups of abdominal surgery patients admitted to an university hospital in D-city : The Bair Hugger and upper body blanket were used with the first group, electrical blanketrol with PVC Film with the second, and the third group was the control. ANOVA was used with the WIN SPSS 17.0 program to analyze the data. Results: Significant differences were found among the three groups for tympanic and esophageal body temperature at 1 hour after starting surgery. There was significant difference in tympanic body temperature during the 15 minute stay in the post anesthetic room. There were no significant differences in thermal discomfort while in the post anesthetic room. or There among the three groups for serum cortisol during surgery. Conclusion: According to the results of this study, application of a Bair Hugger or electrical blanketrol improves maintenance of body temperature of operative patients as well as body temperature of post operative patients, and is a clinically significant warming method providing a more consistent body temperature.

• Journal of Korean society of Dental Hygiene
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• v.3 no.1
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• pp.73-87
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• 2003

This study was performed on 17 female dental hygienists to find an appropriate method to reduce the hygienists' body discomfort while scaling, and provide a foundation to educate them how 10 posture during the process. To assess the arm abduction, elbow flexion, neck flexion, trunk flexion and trunk lateral bending through Video 2D(two dimensional motion) analysis and assessing the risk through the Action level of RULA(rapid upper limb assessment) checklist, an ergonomic analysis method. Correlation analyses on the posture angles and on body discomfort were performed. ANOVA analysis on scaling treatment position and the scaling treatment region of patients was also performed. The results are as following. 1. 20 analysis while scaling, arm abduction was $40{\sim}79.9^{\circ}$, elbow flexion $20{\sim}110^{\circ}$, neck flexion $50{\sim}100^{\circ}$, trunk flexion $60{\sim}80^{\circ}$, and trunk lateral bending $5{\sim}19.9^{\circ}$. 2. The Action level of RULA was 2. 3 resulted from scores 4 and 5 of group A which includes upper arm, lower ann, wrist, and scores 2 and 4 of group B which includes neck, trunk, legs. It means that the scaling treatment posture causes a high incidence rate of musculoskeletal that an additional investigation and improvement should be followed without hesitation. 3. There were significant differences among the maxilla right, maxilla anterior, maxilla left, mandible left, mandible anterior, and mandible right of a patient of the right and left upper arm, lower arm, neck, trunk, group A, group B, final RULA score while scaling treatment. 4. There were significant differences among the time position of 8, 9, 10, 11, 12, 13 of the right and left upper arm, lower arm, neck, trunk, group A, group B, final RULA score while scaling treatment, 5. As for the body discomfort, neck, right shoulder, left shoulder, right back, right wrist etc. were listed on top. As a conclusion, performing the time position of 12 which shows low right and left final RULA scores is better than the time position of 8 and 10 which show high final RULA scores to reduce the body discomfort while scaling treatment.

• Journal of the Ergonomics Society of Korea
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• v.32 no.6
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• pp.549-555
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• 2013

Objective: The purpose of this study was to compare the performance of drilling on the ceiling in three different postures (standing, standing on the ladder and supine on the height adjusted board) and the subjective responses of perceived discomfort after the drilling. Background: Overhead work has been identified as a major occupational risk factor and has been a main research subject. Method: Ten young participants drilled 20 holes at the pre-marked places on the ceiling in three different postures. The drilling duration, resting and drilling heart rate were measured. The levels of perceived discomfort at neck, shoulder, elbow, hand and overall body were asked at the end of each task. Results: The working posture affected the heart rate after the drilling. Perceived discomfort in the neck decreased significantly in supine compared to drilling on the ladder. Conclusion: The results of this study suggest that drilling in supine can be an alternative way to reduce the drilling heart rate and the level of perceived discomfort in the neck without sacrificing the productivity. Application: The results of this study would be considered when drilling on the ceiling is required in construction workers.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.165-170
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• 2012

Objective: The aim of this study is to develop new K-OWAS on the basis of the anthropometry of Koreans considering works in shipbuilding and heavy industry for evaluation whole-body working postures. Background: Work Related Musculoskeletal Disorders(WMSDs) were a leading cause of sick leaves and injuries in the industries of our country. Especially, awkward working postures and handling of heavy weight are known as a main cause of WMSDs. OWAS, RULA and REBA are much used as the method for evaluating the awkward working postures. OWAS is the working postures evaluation method that can be used for the evaluation of whole-body working postures. OWAS was the method made based on the anthropometry of the foreigner, working postures and weight does not fit our work state. Method: This method was evaluated considering the anthropometry of the Koreans, working postures and weight in shipbuilding and heavy industry work state in Korea. Results: Correlation of action level of OWAS and subjective discomfort for each body parts were not statistically significant($p{\geq}0.1$). But correlation of action level of K-OWAS and subjective discomfort for torso and waist were statistically significant($p{\leq}0.1$). Conclusion: K-OWAS was suitable in the evaluation of upper body including torso and waist. Application: New method for whole-body working postures from this study prevent WMSDs and help improvement of working environment and design of working method.