• 대한의용생체공학회:의공학회지
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• 제26권2호
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• pp.101-110
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• 2005

Periosteum and periosteum-derived progenitor cells have demonstrated the potential for stimulative applications in repairs of various musculoskeletal tissues. It has been found that the periosteum contains mesenchymal progenitor cells capable of differentiating into either osteoblasts or chondrocytes depending on the culture conditions. Anatomically, the periosteum is a heterogeneous multi-layered membrane, consisting of an inner cambium and an outer fibrous layer. The present study was designed to elucidate the cellular phenotypic characteristics of cambium and fibrous layer cells in vitro, and to assess whether structural integrity of the tendon in the bone tunnel can be improved by periosteal augmentation of the tendon­bone interface. It was found the cells from each layer showed distinct phenotypic characteristics in a primary monolayer culture system. Specifically, the cambium cells demonstrated higher osteogenic characteristics (higher alkaline phosphatase and osteocalcin levels), as compared to the fibrous cells. Also in vivo animal model showed that a periosteal augmentation of a tendon graft could enhance the structural integrity of the tendon-bone interface, when the periosteum is placed between the tendon and bone interface with the cambium layer facing toward the bone. These findings suggest that extra care needs to be taken in order to identify and maintain the intrinsic phenotypes of the heterogeneous cell types within the periosteum. This will improve our understanding of periosteum in applications for musculoskeletal tissue repairs and tissue engineering.

• 대한의용생체공학회:의공학회지
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• 제30권3호
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• pp.241-246
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• 2009

Since inappropriate muscle forces mean that people cannot perform some activities related to roles of the muscle, muscle forces have been considered as an important parameter in clinic. Therefore, many methods have been introduced to estimate muscle forces indirectly. One of the methods is muscle tissue dynamics and it is widely used in commercial softwares including musculoskeletal model, such as SIMM. They, however, need motion data captured from 3-dimensional motion analysis system. In this study, we introduced an algorithm to estimate muscle forces in real-time by using joint angles. The heel-rise movements were performed for a normal with 3-dimensional motion analysis system, EMG measurement system, and electrogoniometers. Joint angles obtained from electrogoniometers and EMG signals were used to estimate muscle forces. Simulation was performed to find muscle forces using motion data which was imported into musculoskeletal software. As the results, muscle lengths and forces from the developed algorithm were similar to those from commercial software in pattern. Results of this study would be helpful to implement a tool to calculate reasonable muscle forces in real-time.

• 대한인간공학회지
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• 제27권1호
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• pp.1-7
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• 2008

Work related musculoskeletal disorders (WMSDs) have become a hot issue within the Korean workplace for the past several years. Recently, the effect of job related stress on WMSDs, cerebro-cardiovascular diseases, and psychiatric disorders has been steadily increasing. The study conducted questionnaire of Korea version job stress model, WMSDs from NIOSH, CES-D (Center for Epidemiologic Studies Depression Scale), and STAI (State-Trait Anxiety Inventory) against train drivers. The results of this study show that the job stress score of the train drivers is high in the areas of physical environment, job latitude, interpersonal conflict, job insecurity, and organization system. The relation between job stress and WMSDs nd, interpersonal conflict, job insecurity and organizational system. The relation between job stress and depressive disorders showed statistical significance in the areas of job demand, job insecurity and low reward. Finally, the relation between job stress and anxiety disorders showed statistical significance in areas of job demand, interpersonal conflict, job insecurity, organizational system and low reward.

• ETRI Journal
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• 제41권6호
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• pp.850-862
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• 2019

This work investigated three-dimensional (3D) focused microwave thermotherapy (FMT) at 925 MHz for a human tissue mimicking phantom using the time reversal (TR) principle for musculoskeletal disorders. We verified the proposed TR algorithm by evaluating the possibility of 3D beam focusing through simulations and experiments. The simulation, along with the electromagnetic and thermal analyses of the human tissue mimicking phantom model, was conducted by employing the Sim4Life commercial tool. Experimental validation was conducted on the developed FMT system using a fabricated human tissue mimicking phantom. A truncated threshold method was proposed to reduce the unwanted hot spots in a normal tissue region, wherein a beam was appropriately focused on a target position. The validation results of the simulation and experiments obtained by utilizing the proposed TR algorithm were shown to be acceptable. Effective beam focusing at the desired position of the phantom could be achieved.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.728-735
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• 2022

Roofers get exposed to increased risk of knee musculoskeletal disorders (MSDs) at different phases of a sloped shingle installation task. As different phases are associated with different risk levels, this study explored the application of machine learning for automated classification of seven phases in a shingle installation task using knee kinematics and roof slope information. An optical motion capture system was used to collect knee kinematics data from nine subjects who mimicked shingle installation on a slope-adjustable wooden platform. Four features were used in building a phase classification model. They were three knee joint rotation angles (i.e., flexion, abduction-adduction, and internal-external rotation) of the subjects, and the roof slope at which they operated. Three ensemble machine learning algorithms (i.e., random forests, decision trees, and k-nearest neighbors) were used for training and prediction. The simulations indicate that the k-nearest neighbor classifier provided the best performance, with an overall accuracy of 92.62%, demonstrating the considerable potential of machine learning methods in detecting shingle installation phases from workers knee joint rotation and roof slope information. This knowledge, with further investigation, may facilitate knee MSD risk identification among roofers and intervention development.

• 한국정밀공학회지
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• 제24권12호
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• pp.29-35
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• 2007

• 한국정밀공학회지
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• 제24권12호
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• pp.20-28
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• 2007

• 대한안전경영과학회지
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• 제11권4호
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• pp.57-67
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• 2009

The psychosocial stress and musculoskeletal disorders(MSDs) have been one of major health problems for hospital workers. This study tried to understand the relationship between symptoms associated with MSDs and risk factors such as working posture, job stress, psychosocial stress and fatigue. A total number of 655 hospital workers participated in this study. Specifically, REBA was applied for evaluating working posture and a checklist prepared by KOSHA(Korean Occupational Safety and Health Agency) was used for symptom survey. A questionnaire from KOSHA was also used for collecting data associated with job stress, psychosocial stress and fatigue. All these data were formulated and modeled by path analysis which was one of major statistical tools in this study. Specifically, path analysis for the data we collected came up with several major findings. As a result, as for body part(neck), (waist) and (arms) the degree of risk of work posture measured with the use of job stress(KOSS), psycho-social stress(PWI-SF) and REBA is significantly more affected by fatigue than muscular skeletal disease related consciousness symptom. However, regarding bod(wrist), the degree of risk of work posture measured with the use of job stress(KOSS) and REBA is directly affected by muscular skeletal disease related consciousness symptom. This study is meaningful in that the study clarified the causal relations of the degree of risk of work posture, degree of fatigue, and muscular skeletal disease related consciousness symptoms by each body part measured with the use of work stress(KOSS), psycho-social stress(PWI-SF) and REBA.

• 대한간호학회지
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• 제48권6호
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• pp.692-707
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• 2018

Purpose: We aimed to examine the effects of an integrated physical activity (PA) program developed for physically inactive workers on the theoretical basis of the PRECEDE-PROCEED model. Methods: Participants were 268 workers in three departments of L manufacturing unit in South Korea. The three departments were randomly allocated into integration (n=86) (INT), education (n=94) (ED), and control (n=88) (CT) groups. The INT group received self-regulation, support, and policy-environmental strategies of a 12-week integrated PA program, the ED group received self-regulation strategies only, and the CT group did not receive any strategies. After 12 weeks, process evaluation was conducted by using the measures of self-regulation (autonomous vs. controlled regulation), autonomy support, and resource availability; impact evaluation by using PA measures of sitting time, PA expenditure, and compliance; and outcome evaluation by using the measures of cardiometabolic/musculoskeletal health and presenteeism. Results: Among process measures, autonomous regulation did not differ by group, but significantly decreased in the CT group (p=.006). Among impact measures, PA compliance significantly increased in the INT group compared to the CT group (p=.003). Among outcome measures, the changes in cardiometabolic/musculoskeletal health and presenteeism did not differ by group; however, systolic blood pressure (p=.012) and a presenteeism variable (p=.041) significantly decreased only in the INT group. Conclusion: The integrated PA program may have a significant effect on increases in PA compliance and significant tendencies toward improvements in a part of cardiometabolic health and presenteeism for physically inactive workers. Therefore, occupational health nurses may modify and use it as a workplace PA program.

• 농촌의학ㆍ지역보건
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• 제44권4호
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• pp.209-219
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• 2019

이 연구는 치과위생사의 직무스트레스와 상지의 근골격계 기능 장애의 관련성을 알아보고자 수행하였다. 연구 대상자는 부산·경남 지역의 병원급 이상, 치과의원에 근무하는 치과위생사를 220명을 편의 표집하여 설문지를 배포한 후 최종 수거된 200부에서 응답이 부실한 2부를 제외하고 최종적으로 198명의 자료를 분석하였다. 설문문항으로는 일반적 특성, 직무스트레스, 작업관련 상지 근골격계 통증, 동작수행능력에 따른 기능평가 문항으로 구성하였다. 치과위생사의 대한 상지근골격계질환 통증은 목 39.4%, 어깨 54.6%, 팔/팔꿈치 14.7%, 손/손목/손가락 50.0% 였다. 그리고, 상지의 기능 장애는 치과위생사에서 호발하는 건강관련 문제로 불편한 작업자세와 상지 부위별 근골격계 통증을 보정하더라도 직무스트레스와 유의한 관련이 있었다. 즉, 팔꿈치를 굽혔다 펴는 반복 작업, 팔꿈치 부위에 통증이 있는 경우외에도 직무스트레스 역시 상지의 기능 장애와 관련이 있었다. 치과위생사의 직무스트레스는 이들의 상지 기능 장애로 이어져 결과적으로 의료서비스의 저하로 이어지므로, 장단기 계획하에 근무환경개선 등을 통하여 직무 스트레스를 감소시킬 수 있는 방안을 모색하여야 할 것이다.