• 대한인간공학회지
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• 제19권2호
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• pp.15-31
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• 2000

The aim was to evaluate the prevailing ergonomic and psychosocial conditions regarding low back injury in an automobile assembly system. This study consisted of two parts. In the first part of the study, analytic biomechanical model and NIOSH guidelines were applied to evaluate risk levels of low back injury for automobile assembly jobs. Total of 246 workers were analysed. There were 20 jobs having greater back compressive forces than 300kg at L5/S1. Also, there were 44 jobs over Action Limit with respect to 1981 NIOSH guidelines. This might in part be explained by the ergonomic conditions of the company analysed generally being good, with a relatively low duration of 'combined' extreme work posture. The relationship between psychosocial factors and low back injury was examined in the second part of the study. It has recently been recognized that overall reaction to working conditions was influenced by a range of factors, some of which were physical and some psychosocial. The psychosocial environment surrounding the work place may contribute to the perception of risk and eventual ill-health. A battery of questionnaires concerning the psychosocial stress based on PWI(Psychosocial Well-being Index) and musculoskeletal pain symptoms at low back was completed by 246 workers at the same plant. Results showed that 207 out 246 workers experienced the symptoms and 27 workers were diagnosed as patients. Two groups(low stressed, high stressed) based on PWI score had no significant relationships with both symptoms and results of diagnosis. However, sensitivities for symptoms and diagnosis by PWI were 91.3% and 92.6% respectively. Finally, relationships between physical work load and psychosocial stress were analysed. Specifically, some postural factors {vertical deviation angle of forearm, horizontal deviation angle of upperarm, vertical deviation angle of thigh, etc) were highly correlated with psychosocial stress. The results illustrated that PWI scores were associated with some physical workloads. However, psychosocial stress levels couldn't be well related with the pain symptom as well as the actual incidence of low back injury since pain or discomfort regarding low back injury were more complex than that of other musculoskeletal disorders.

• 한국의상디자인학회지
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• 제19권4호
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• pp.123-137
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• 2017

The purpose of this study is to suggest sleeve cap height with a satisfying wearing sensation and appearance on jackets for women in their twenties so that high-consumer demand jackets can be produced. Five experimental jackets with sleeve cap heights of [(AH/3)-1cm], [(AH/3)-0.5cm], [AH/3], [(AH/3)+0.5cm] and [(AH/3)+0.8cm] were made for 30 subjects to try on after which the subjects were then surveyed for their assessment of appearance, wearing sensation and preference. On the basis of the results, the optimum height of the sleeve cap has been proposed along with the following contents and results of this research. 1. [AH/3] [(AH/3)+0.8cm] of sleeve cap height was assessed to beof desirable appearance. 2. [AH/3] of sleeve cap height garnered a high opinion in terms of intuitive wearing sensation, while [(AH/3)-1cm] [AH/3] were the heights with overall satisfaction of intuitive and movement wearing sensations. If discomfort in the upper sleeve at 'straight arm' posture can be tolerated, the sleeve cap height can be set to [(AH/3)-1cm]~[(AH/3)+0.5cm]. 3. [AH/3] and [(AH/3)+0.5cm] were found to have a high preference among wearers, which indicated that the women in their twenties prefer a slim type of sleeve, putting appearance above wearing sensation. Consequently, [AH/3] is desirable when appearance, wearing sensation and preference are considered, [(AH/3)+0.5cm] is fit for business uniform for static duties or formal dress focused on aesthetic impression and [(AH/3)-1cm]~[AH/3] are desirable for work clothes when considering active duties.

• The Journal of Korean Physical Therapy
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• 제29권1호
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• pp.7-15
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• 2017

Purpose: This randomized controlled trial was conducted to compare the effectiveness of global postural reeducation to segmental stretching in subjects with neck and shoulder pain. Methods: Sixteen subjects with neck and shoulder pain were randomized into two intervention groups, a global posture reeducation group (n=8) that performed muscle chain stretching, and a segmental stretching group (n=8) that performed conventional static muscle stretching. The intervention program consisted of two 40 minutes individual sessions per week for four weeks. Subjects were evaluated pre-intervention, two-week after intervention and at a four-week follow-up appointment for pain intensity, disability and health-related quality of life. Two-way repeated analysis of variance was used for between-time and between-group comparisons. The significance level was 0.05. Results: Significant pain relief and decreasing discomfort of the neck and shoulder were observed after intervention in both groups, and there was an interaction between time lapse and groups (pain, F=10.31, neck disability, F=25.45, shoulder disability, F=12.82, p<0.05). Quality of life also improved after intervention in both groups. Moreover, the physical components score improved, and a significant interaction was observed between time and groups (F=4.85, p<0.05). However, no significant improvement in mental component score of quality of life and no significant interaction between time and groups were observed (p>0.05). Conclusion: These findings suggest that a GPR intervention in subjects with neck and shoulder pain induces greater improvement of pain and disability and quality of life than segmental stretching.

• 한국실내디자인학회논문집
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• 제24권6호
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• pp.154-162
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• 2015

As there is no case study with current status, measurements or description on the state of actual site of rural area only, the delivery of actual conditions about such an area is significantly limited. The purpose of this study is to pinpoint issues with housing conditions of low-income family with disabled members in the rural area. For such a purpose, 25 households of disabled people have been visited for interview, on-site research and survey, of which results are summed up in this paper as following: First, average monthly income of such family turned out to be KRW 480,000, most of which is from the government subsidy. High ratio of such families has resided in a house with average size of approximately 56m2 for about 24 years. Secondly the most needed maintenance work with top priority was for the toilet, and many of the interviewees expressed their discomfort about small size of their bathrooms and inconvenient facilities therein. Thirdly, most of such houses had too high thresholds that posed danger and inconvenience. Such thresholds had average height of 13cm, which can be considered as completely inconsiderate of disabled users. Fourth issue was that these people needed safety handle that will enable them to stand up or to be in the standing posture in the living room and bedroom where they spend most of their time. Fifthly, they wanted finishing materials with waterproof functionality as well as replacement of finishing materials and wallpaper which were too old and caused hygiene issues. As these issues represent, current housing for disabled people in the rural area turned out to be poor and risky space rather than the place where difficulty of individual situation can be resolved or their disability can be complemented. Thus it can be determined that now is the time to arrange the solutions for such housing difficulties and to establish customized housing plan to ensure safety and convenience.

• 대한인간공학회지
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• 제33권2호
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• pp.135-142
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• 2014

Objective: This study aims to develop a new desk with a built-in bookholder and desktop-mounted sliding drawer for reducing stress of seated reading postures and to analyze its effect. Background: It is general for readers to bend their back and neck when reading books on desks, which may result in high back and neck postural stress. In addition, postures using vertically layered drawers positioned at the side of users may be awkward. Method: For reducing the postural stress, a new desk with a built-in bookholder and sliding drawer was developed based on a standard of KS G 4208 for student desk. The muscle activities of reading postures on both existing and new desks were measured using EMG, in which seven male and three female college students participated. The postural stress, and musculoskeletal discomfort and ease of usage for existing and new drawers were analyzed by RULA and questionnaire survey, respectively. Results: Compared to existing desk, the muscle activity for the new desk with a bookholder was reduced by 47% when reading books. In addition, musculoskeletal discomforts in the shoulder, neck and low back were significantly lower when using the new desk with a bookholder. Although the stresses for postures using the desktop-mounted sliding drawer and general drawer were not significantly different, the questionnaire survey revealed that the new desktop-mounted sliding drawer is easier to use. Conclusion: A new desk developed in this study significantly reduced postural stress and enhanced subjective preference when reading. Application: This would be useful when developing new desks with low postural stress.

• 대한인간공학회지
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• 제33권2호
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• pp.143-153
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• 2014

Objective: The aim of this study is to investigate the effects of trunk-forearm supported sitting on trunk flexion angle, trunk extensor fatigue and seat contact pressure. Background: The relationship between sitting posture and musculoskeletal disorders of the trunk extensor fatigue and seat contact pressure has been documented. The trunk-forearm support type ergonomic chair was devised from the fact that trunk-forearm support has been reported to reduce trunk extensor activity and discomfort. Method: Using three different sitting postures, upright ($P_1$), trunk-forearm supported ($P_2$) and normal sitting ($P_3$), six healthy subjects participated in the study. Motion capture system was used to collect head and trunk flexion angle, and surface electromyography (sEMG) was used to collect myoelectric signal of upper trapezius, lower trapezius, erector spinae, multifidus, and pressure mat system was used to measure seat contact pressure. Results: When trunk and forearm were supported by the ergonomic chair, higher head flexion angle showed upright > trunk-forearm supported > normal in order, and muscle fatigue showed less than upright and normal sitting. Mean seat contact pressure decreased 19% than upright sitting. But muscle fatigue was not affected by each condition. Conclusion: Trunk-forearm supported sitting of the ergonomic chair showed positive effect in respect of trunk and head flexion angle, trunk extensor fatigue, seat contact pressure. To acquire comprehensive understanding of the effectiveness of the ergonomic chair, further studies such as anatomical effects from measurement of external applied loading effect to the body from interface pressure analysis are required. Application: The results of the publishing trend analysis might help physiological effects of trunk-forearm support type chair.

• 한국의류산업학회지
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• 제19권4호
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• pp.504-514
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• 2017

Discomfort as well as muscular pain and musculoskeletal diseases occur in cases of stressed posture due to prolonged pressure. Therefore, the American Academy of Orthopaedic Surgeons (AAOS) and Pediatric Orthopaedic Society of North America (POSNA) recommend that bags that weigh no more than 15 - 20% of the wearer's weight. However, despite the prolonged pressure from using baby carriers, there are no recommendations and limited studies on how to protect wearers. Therefore, this study investigates subjective fatigue according to the usage of waist support and hip seat. Based on this, muscle fatigue and secondary subjective fatigue according to three types of currently commercial baby carriers (X-type, H-type, and H-hip type) were measured. Subjective comfortability was evaluated on a 5 point Likert-scale and subjective fatigue was evaluated on Borg's CR-10 scale. Objective muscle fatigue was also compared by measuring and analyzing electromyogram (EMG). The results of primary subjective fatigue showed statistically significant changes in the shoulders, waist, calves, and soles of the feet according to the usage of hip seats and waist support. Electromyogram measurements also showed less muscle fatigue at the upper trapezius muscle and thoracic erector spine muscle for the H-hip seat baby carrier, which has both waist support and hip seat, compared to an X-type baby carrier, which has neither. However, results of subjective fatigue showed opposite results at the waist despite having same results at the shoulders and beneath the shoulders. This show discrepancies between objective muscle fatigue and subjective fatigue; therefore, that both aspects must be taken into consideration when developing ergonomic baby carriers.

• 복식문화연구
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• 제25권3호
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• pp.301-314
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• 2017

This study focused on the movement adaptability of $19^{th}$ century classical opera stage costumes. Researchers focused on a basic $19^{th}$ century women's jacket. The study analyzed movement adaptability using ROM (range-of-motion) tests of the upper limb flexion and abduction postures. It developed two research garments to mimic basic $19^{th}$ century style jackets with or without gussets at the axilla. The ROM experiment identified the gusset size as 11cm in length. Experimental postures included upper limb flexion and abduction. The study measured subjective comfort at 8 postures. These postures included the flexion and abduction of the arms and torso. Subjects also evaluated the subjective comfort of the rotation posture of the torso. Researchers evaluated the similarities between research garments' silhouettes and the $19^{th}$ century women's jacket. The study used a 3D virtual fitting system to evaluate fit, and specialists further analyzed fit with photographs and 3D virtual graphics. The results are as follows. The silhouettes of both research garments were similar to the silhouettes of the $19^{th}$ century western women's jacket. The jacket with axilla gusset had a better fit than the basic style jacket. The basic style jacket without the axilla gusset showed limited movement adaptability at the shoulder joint and it caused discomfort at the axilla and elbow. The 3D virtual fit test was not a suitable method for analyzing silhouette similarity.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.407-408
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• 2016

드론은 최근 가까운 공원에서도 볼 수 있을 정도로 대중화가 되었다. 드론이란 조종사 없이 무선전파로 비행 조종이 가능한 무인 항공기(UVA)를 말하며, 주로 비행기나 헬리콥터 모양을 하고 있다. 드론은 군사용으로 시작 되었지만, 최근 방송촬영, 농약살포, 현장탐사, 취미용 등 민간으로 용도가 확대 되었다. 하지만 시중에서 많이 볼 수 있는 드론은 가격도 비싸고 고장이 났을 경우 수리하기가 어려우며, 비행시간이 짧은 불편함이 있다. 본 논문에서는 위에서 말한 불편한 점을 해결하고자 가격이 저렴한 ATmega128을 이용한 드론(쿼드콥터)를 구현했다. 6축 자이로, 가속도 센서와 MCU간의 TWI통신과, PID제어를 통한 드론의 자세제어를, 수신기의 신호를 입력받아 송신기로 드론을 제어하는 동작을 C프로그래밍언어를 기반으로 구현하였다.

• 대한인간공학회지
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• 제29권6호
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• pp.933-942
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• 2010

Objective: To develop an ergonomic evaluation tool which can be apply to assess the lower-limb postures associated with farming tasks. Background: In general, most of existing ergonomic assessment tools was developed to investigate the work-related musculoskeletal disorders of the upper-limb postures in manufacturing industry. Methods: As the first step of development of the evaluation tool, 13 lower-limb postures that were commonly observed in farming task were investigated by the subjective discomfort ratings, heart rates, and muscle activities. And then, an ergonomic evaluation tool for the lower-limb postures was developed based on results of the first experiment. Lastly, the ergonomic checklist which was developed in the current study was compared with other existing ergonomic assessment tools. Results: Based on the results of comparisons between a newly developed assessment tool and other existing assessment tools, it was found that a newly developed tool can perceive more sensitively for the various lower-limb postures than other assessment tools. Conclusions: Lower-limb posture assessment tool which can evaluate and assess risks of lower-limb WMSDs which were prevalent in farming tasks more easily and accurately was developed in this study. The lower-limb assessment tool can also be utilized to prevent WMSDs related with lower-limbs as well as improve working environments.