• Safety and Health at Work
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• v.13 no.3
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• pp.315-325
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• 2022

Background: Firefighters are required to carry self-contained breathing apparatus (SCBA), which increases the risk of musculoskeletal disorders. This study assessed the newly recruited firefighters' internal forces and potential musculoskeletal disorders when carrying SCBA. The effects of SCBA strap lengths were also evaluated. Methods: Kinematic parameters of twelve male subjects running in a control condition with no SCBA equipped and three varying-strapped SCBAs were measured using 3D inertial motion capture. Subsequently, motion data and predicted ground reaction force were inputted for subject-specific musculoskeletal modeling to estimate joint and muscle forces. Results: The knee was exposed to the highest internal force when carrying SCBA, followed by the rectus femoris and hip, while the shoulder had the lowest force compared to the no-SCBA condition. Our model also revealed that adjusting SCBA straps length was an efficient strategy to influence the force that occurred at the lumbar spine, hip, and knee regions. Grey relation analysis indicated that the deviation of the center of mass, step length, and knee flexion-extension angle could be used as the predictor of musculoskeletal disorders. Conclusion: The finding suggested that the training of the newly recruits focuses on the coordinated movement of muscle and joints in the lower limb. The strap lengths around 98-105 cm were also recommended. The findings are expected to provide injury interventions to enhance the occupational health and safety of the newly recruited firefighters.

• Biomedical Science Letters
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• v.29 no.1
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• pp.26-33
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• 2023

Ziziphus jujuba Mill. (ZJM), a traditional folk medicine and functional food in South Korea and China, has been reported to having pharmacological activities against anti-cancer, anti-oxidative, and anti-obesity. However, the effect of ZJM related to myoblast differentiation has not been known. In this study, we investigated the effects and mechanism of ZJM on myogenic differentiation of C2C12 cells. ZJM promotes myogenic differentiation and elevates the formation of multinucleated myotube compared to the control group. ZJM significantly increased the mRNA and protein expression of MyHC1, myogenin and MyoD in dose- and time-dependent manner. Interestingly, ZJM significantly inhibited the mRNA and protein expression of protein degradation markers, atrogin-1 and MuRF-1, in dose- and time-dependent manner. Taken together, our data suggest that ZJM is a potential functional candidate for muscle growth and strength by promoting myogenic differentiation.

• The Korean Journal of Pain
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• v.36 no.1
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• pp.106-112
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• 2023

Background: Most international bodies recommended against musculoskeletal steroid injection during the COVID-19 pandemic, fearing that the immunosuppressive effects of the steroid could worsen COVID-19 infection, thus prolonging the suffering of patients with severe musculoskeletal disease. The authors' aim is to analyze the risk of COVID-19 infection after musculoskeletal injections. Methods: This is a retrospective study of patients who visited a sports medicine clinic and received musculoskeletal steroid injections between January 1, 2020 and February 28, 2021. The collected data was compared with the national COVID-19 registry to identify positive COVID-19 patients. The patients were only considered positive for COVID-19 following corticosteroid injection within 3 months after injection. Results: Out of 502 steroid injections; 79.7% (n = 400) received a single injection in one day, 19.1% (n = 96) received steroid injections at 2 sites in one day, and 1.2% (n = 6) received steroid injections at 3 sites in one day. Using the Fisher's exact test, there was no statistically significant association of COVID-19 infection between the steroid group and control group (relative risk, 1.44; 95% confidence interval, 0.9-23.1, P = 0.654). Only one patient contracted mild COVID-19 with no post COVID complications. Conclusions: The authors recommend the use of musculoskeletal steroid injections in clinically indicated situation without having increased risk of COVID-19.

• Journal of Korean Dental Hygiene Science
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• v.1 no.1
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• pp.1-10
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• 2018

From October 01, 2017 to October 30, 2017, Busan. The following are the results of 185 studies on the identification of lifestyle habits and subjective symptoms of musculoskeletal disorders in Kyungnam dental hygienists. 1. The dental hygienist's lifestyle showed more regular exercise with age, and there was a significant difference according to age(χ²=34.17, p<.001). 2. The housework habits were more than 1 hour for older dental hygienists, and there were significant differences according to age(χ²=66.09, p<.001). 3. In the case of musculoskeletal diseases with or without age, dental hygienists experienced musculoskeletal disorders in the past and showed a significant difference according to age(χ²=39.51, p<.001). 4. 35~39 years old Dental hygienist There were present musculoskeletal diseases and there was a significant difference according to age(χ²=45.44, p<.001). 5. There was a significant difference between the dental hygienists aged 35~39 years due to musculoskeletal disorders and age(χ²=24.19, p<.001). As described above, the dental hygienist needs to adjust the work in consideration of the year, and in the case of low annual, measures are needed to prevent the disease.

• Journal of dental hygiene science
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• v.15 no.4
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• pp.472-479
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• 2015

The purpose of this study is to examine musculoskeletal disorders and grasp the relationship between working environment factors and stress and musculoskeletal disorders in dental hygienists. The self-administered questionnaire survey was conducted with 483 dental hygienists working in Gwangju who were selected by convenience sampling. Frequency analysis, crosstab analysis, t-test, and multiple logistic regression analysis were made. Subjects' musculoskeletal disorders that complain of severe pains were 29.8%. The relationship between working environment factors and stress and musculoskeletal disorders were examined. As a result, work break frequency of working environment factors and stress were found to influence musculoskeletal disorders. For working environment factors, the odds ratio of musculoskeletal disorders of the two breaks group was 0.29 (95% confidence interval [CI], 0.11~0.73), compared with the no break group, indicating less musculoskeletal disorders. However, no significant difference was found in one break and more than three breaks groups. The odds ratio of musculoskeletal disorders of stress was 0.44 (95% CI, 0.27~0.70), indicating negative correlation. As break frequency was moderate (two breaks), musculoskeletal disorders became decreased. Stress showed negative correlation with musculoskeletal disorders.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.30 no.3
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• pp.93-110
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• 2019

This study surveyed 129 librarians of public libraries in the northwestern region of Seoul to identify harmful factors under the assumption that the work and environmental factors of them would burden their musculoskeletal system and influence their work satisfaction. The results of this study showed that the musculoskeletal symptoms in the shoulder, one of the general items, were more frequently observed in women than in men. Secondly, the musculoskeletal symptoms in the arms and elbows, one of the working environment characteristics, were most frequently reported when they worked more than one year and less than three years. The musculoskeletal symptoms in the waist were influenced by the operation method; the librarians of public libraries entrusted to the Office of Education or a local government showed symptoms more frequently. The musculoskeletal symptoms in the neck were affected by working hours; librarians working in the day shift showed neck symptoms more frequently than those working in the night shift. Thirdly, when the characteristics of the work environment were examined, the musculoskeletal symptoms in the hands, wrists, and fingers were highly frequent under all characteristics of the work environment, the musculoskeletal symptoms in the waist were highly frequent under all characteristics of the work environment except for work satisfaction, and the musculoskeletal symptoms in the legs and feet were highly frequent according to the proficiency, work intensity, and physical burden. Fourthly, this study evaluated the differences in musculoskeletal symptoms according to the work satisfaction of individuals. The results revealed that the occurrence frequency of musculoskeletal symptoms for all body parts decreased as work satisfaction increased. Therefore, it will be necessary for the main body of public library operation to improve the work and working environments and enhance the work satisfaction of individuals by reducing the physical burden of the librarian of public libraries through adjusting the work intensity in order for the health of the librarian of public libraries.

• The Journal of the Korean bone and joint tumor society
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• v.1 no.1
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• pp.68-76
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• 1995

To evaluate the clinical result of surgical treatment of malignant tumors in shoulder girdle, nine patients who were treated in Department of Orthopedics, Catholic University Medical College between January 1991 and December 1993, were evaluated. There were 5 men, 4 women. The mean age at operation was 47 years(range from 22 to 64 years). Of 9 patiens, 2 were soft tissue tumors(1 MFH, 1 dermatofibrosarcoma protuberance); one was treated with forequarter amputation, and the other with wide excision, Seven were bone tumor(2 chondrosarcoma, 1 osteosarcoma, 1 MFH, 1 plasmacytoma, 1 thyroid carcinoma metastasis, 1 malignant schwannoma); one patient was treated with segmental excision of proximal humerus, 4 with Malawer type I-A resection and arthroplasty or arthrodesis, 1 with Malawer type V-B resection and arthrodesis. Five patients received adjuvant chemotherapy, with or without local radiation therapy, and one patient received radiation therapy alone. All patients have survived now, but I had local recurrence. Functional results of arthrodesis and arthroplasty were similar.

• Journal of the Ergonomics Society of Korea
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• v.34 no.6
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• pp.609-622
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• 2015

Objective: This study aims to investigate the correlation between office and work environment satisfaction levels and workers' musculoskeletal symptoms by conducting surveys asking office workers to state their musculoskeletal symptoms and office and work environment satisfaction levels. Background: The increased number of office workers and their indoor work hours using computers have led to new understandings of the importance of office environment including its temperature, humidity, noise levels, lighting and quality of air, and work environment including monitor arrangement, space arrangement and the functions of desks and chairs. Method: Specific details on office work, office environment satisfaction levels, work environment satisfaction levels, musculoskeletal symptoms, absence from work and treatment due to musculoskeletal related symptoms were analyzed based on the survey answers given by 397 office workers who were the subjects of this research. Results: Office workers showed different characteristics of musculoskeletal symptoms depending on their gender, age, work experience, office hours, break time and time spent on computers. Also, differences in symptoms were found for workers'with different satisfaction levels for office environment (temperature, humidity, noise levels, quality of air, lighting) and work environment (location of monitors, area and display of office space, chairs and desks). ANOVA shows the differences between groups of subjects classified by the experience of work-absences and treatments or pain complaints. Conclusion and Application: Relationship between workers' satisfaction levels with the office and work environment and their musculoskeletal symptoms is expected to be served as essential data for systematic management of the workplace.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.1
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• pp.13-19
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• 2015

Objectives: The purpose of this study was to assess excavator drivers in order to determine the proportion showing subjective symptoms of musculoskeletal disorders and to evaluate the association between the symptoms and characteristics of the subjects. Methods: A questionnaire survey was conducted to collect the information on participants' age, average working hours per day, duration of career (years), work-related musculoskeletal symptoms, and more. The final dataset included 141 excavator drivers. Frequency and percentage were summarized and then the associations between the characteristics of the subjects and symptoms were evaluated as odds ratios (ORs) and 95% confidence intervals (CIs) using multiple logistic regression analysis. Results: Seventy-six percent of the currently reported musculoskeletal symptoms. Those who have musculoskeletal symptoms attributed their symptoms to unstable posture at work, mental stress or vibrations. There was a significant association between symptoms of musculoskeletal disorders and career of excavator drivers (P for trend=0.04). Conclusions: The results of this study suggest that the prevalence of musculoskeletal disorders may be high among excavator drivers and warrants well-designed studies on work-related disorders among excavator drivers.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.2
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• pp.122-132
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• 2008

The purpose of this study is to present the basic materials of a developmental counterplan by assessing prevalence of musculoskeletal symptoms and characteristics of work-related ergonomic risk factors. The prevalence of musculoskeletal symptoms of 64 vineyard workers was investigated by using a self-reported questionnaire. And the vineyard workers' tasks were also collected and analyzed during 9-month period by observing and videotaping methods to identify the ergonomic risk factors. The prevalence rate of musculoskeletal symptoms of female(84.4%) was much higher than that of male(62.5%) and a total prevalence rate was 73.4%. There was no different prevalence of musculoskeletal symptoms between age over 60 years and under 60 years. The prevalence rates of musculoskeletal complaints for each body part were 48.4%, 42.2%, and 35.9% for the wrist, legs/knee, and shoulder, respectively. In postural risk analysis, 7 works(REBA score) represented the high risk tasks such as delivering harvest boxed(12), picking cluster(11) and so on. The main works(exposure score) were orderly ranked as picking cluster(1590), pruning branch(388), and cluster thinning(327). The risk factors of vineyard work were identified as follows: shoulder flexion(${\geq}45^{\circ}$), wrist Flex./Ext.(${\geq}15^{\circ}$), hand force(power/pinch-grip), and prolonged standing(${\geq}4hr$). The engineering solutions including an improvement of hand tools, working process, and working environment should be applied to the high risky tasks in order to resolve the ergonomic problems. The administrative solutions such as improving a distribution of resting time, an exercise cure, an early recognition of symptoms and rehabilitation might be another solution for reducing musculoskeletal symptoms in vineyard workers.