• 대한인간공학회지
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• 제16권1호
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• pp.73-83
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• 1997

It is improtant to get accurate information about the grip strength for designing ergonomic grips and handles. It has been known that the excessive and repetitive use of grip force and unnatural posture of the wrist may cause cumulative trauma disorders (CTDs) such as carpal tunnel syndrome, tendrome, tendonitis, DeQuervan's disease, etc. In this paper we have measured the grip strength for sitting and standing posture for Korean adults ; 114 males and 105 females aged from the 20's to above the 50's. And this paper performed statistical analysis for deriving characteristics between grip strength and anthropometric data. The results are as follows ; (1) The maximum grip strength posture is exerted under standing posture with the elbow in full extension (180 .deg. ) for both males and females (2) There is significant difference among posture, sex and right and/or left handedness (3) Grip strength decreases with age for male, but it traces an inverted U curve for female (4) Grip strength has corre- lations with the age, weight, height, BSA, forearm length, hand length, thickness of wrist, circumference of wrist, and breadth of wrist for males.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.72-73
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• 2016

Working Posture is an important factor directly connected with quality and productivity of the construction project. In particular, High-rise building construction is required to manage the working posture due to the repetitive task and unfavorable working condition such as high place work, limited space. However existing construction planning of high-rise building construction has a negative effect on the labor's productivity because it is not insufficiently considered for working posture. Therefore the purpose of this study is to suggest a work that needs improvement by analyzing labor's working posture quantitatively using OWAS method. These results would provide the basic information to improve the productivity of the construction project by supporting the construction plan considering the working posture in high-rise building.

• The Journal of Korean Physical Therapy
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• 제31권3호
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• pp.151-156
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• 2019

Purpose: This study aimed to investigate the immediate effects of posture correction and real-time visual feedback using a video display on muscle activity and change of head position during overhead arm lift test in individuals with forward head posture. Methods: Fifteen subjects with forward head posture and fifteen normal subjects who volunteered were included in this study. During both groups performed the overhead arm lift test, the muscle activity of the upper trapezius, serratus anterior, sternocleidomastoid, and lower trapezius muscle were measured using electromyography, and head position change was measured using photographs. Then, forward head posture group was asked to perform overhead arm lift test again after posture correction and real-time visual feedback using a video display respectively. One-way analysis of variance (ANOVA) was used to analyze four conditions: pre-test, posture correction, real-time visual feedback, and the control group. Results: The upper trapezius and lower trapezius muscle activity significantly decreased posture correction, real-time visual feedback, and control group than pre-test of forward head posture group (p<0.05). The sternocleidomastoid muscle significantly decreased real-time visual feedback and control group than pre-test of forward head posture group. Head position change significantly decreased three conditions than pre-test of forward head posture group and real-time visual feedback and control group significantly decreased than posture correction. Conclusion: This study recommend for maintaining cervical stability during the overhead arm lift test, postural control using real-time visual feedback is more effective in subjects with forward head posture.

• PNF and Movement
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• 제18권1호
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• pp.45-53
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• 2020

Purpose: This study investigated the correlation between standing balance and head-forward posture in adolescents. Methods: The participants in this study were 15 female adolescents. We took photographs of the participants' craniovertebral angle with a digital camera to determine the degree of head-forward posture. Standing balance was evaluated using the 30-second Romberg test of BT4. The measurements were taken on a stable-support surface and on an unstable-support surface using a balance pad. The data measured in this study were analyzed using SPSS version 23.0, and the statistical significance level α was established as 0.05. Pearson correlation coefficient analysis was performed to identify the correlation between the degree of head-forward position of the participants and their balance ability. Results: When we measured 30 seconds of the Romberg test, we observed that, with their eyes open, the participants' head-forward posture and balance were not correlated. However, with their eyes closed, there was a strong correlation between the forward position of the head and the balance ability, which declined as the head position increased. Conclusion: Adolescents with severe head-forward posture exhibited problems with balance in posture control with closed eyes when visual information was not available. It can be inferred that an abnormality occurs in proprioceptor sensation due to their habitual head-forward posture. Education on correct posture and preventive activities should be recommended to improve the health of such adolescents and avoid possible future problems of physical deterioration.

• 전기학회논문지
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• 제65권9호
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• pp.1557-1563
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• 2016

According to recent studies, poor sitting posture of the spine has been shown to lead to a variety of spinal disorders. For this reason, it is important to measure the sitting posture. We proposed a strategy for classification of sitting posture using machine learning. We retrieved acceleration data from single tri-axial accelerometer attached on the back of the subject's neck in 5-types of sitting posture. 6 subjects without any spinal disorder were participated in this experiment. Acceleration data were transformed to the feature vectors of principle component analysis. Support vector machine (SVM) and K-means clustering were used to classify sitting posture with the transformed feature vectors. To evaluate performance, we calculated the correct rate for each classification strategy. Although the correct rate of SVM in sitting back arch was lower than that of K-means clustering by 2.0%, SVM's correct rate was higher by 1.3%, 5.2%, 16.6%, 7.1% in a normal posture, sitting front arch, sitting cross-legged, sitting leaning right, respectively. In conclusion, the overall correction rates were 94.5% and 88.84% in SVM and K-means clustering respectively, which means that SVM have more advantage than K-means method for classification of sitting posture.

• 대한통합의학회지
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• 제8권3호
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• pp.11-20
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• 2020

Purpose : The purpose of this study was to determine the correlation between smartphone use, body composition, posture and muscle properties of elementary school students. Methods : A total of 22 healthy elementary school students in Daejeon, South Korea, participated in this study with informed consent. Smartphone use was evaluated with Smartphone addiction self-report scale (S-scale) for youth. Body composition (BMI, percent body fat, body fat mass, and skeletal muscle mass) was measured using Inbody. To assess posture, forward head posture and round shoulder posture were measured using Dartfish motion analysis. Muscle properties (muscle tone, stiffness, and elasticity) were measured on the upper trapezius, splenius capitis and sternocleidomastoid muscles using Myoton. To investigate the correlation between the main variables, Pearson correlation analysis was performed. Results : Disturbance of adaptive function, which is one of sub-component of S-scale, had a weak positive correlations with BMI (r=.538, p<.01), and body fat mass (r=.453, p<.05). However, scores of S-scale showed no correlation with posture and muscle properties. The correlation between posture and muscle properties was analyzed, and round shoulder posture revealed a weak positive correlation with respect to stiffness (r=.418, p<.05) and elasticity (r=.502, p<.05) of the sternocleidomastoid muscle. Conclusion : Scores of S-scale demonstrated a weak correlation with body composition (BMI) among elementary school students, whereas S-scale scores were not correlated with the posture and muscle properties. Further research is needed to identify and focus on potential high-risk user groups of elementary students who are more dependent upon smartphones.

• 전자공학회논문지
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• 제52권6호
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• pp.117-125
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• 2015

앉아있는 시간이 긴 현대인들에게 바른 자세를 유지하도록 하는 것은 중요하다. 자세 교정을 위한 치료는 많은 시간과 비용이 소요되며, 전문의의 지속적인 관찰이 필요하다. 그러므로 사용자 스스로 자신의 자세를 판단하고 교정하기 위한 시스템이 필요하다. 본 논문에서는 사용자의 자세 데이터를 취득하여 취득된 자세가 정상자세인지 비정상자세인지 판단한다. 사용자의 자세 데이터 취득을 위해 관성 센서를 이용한 4개 관절 기반 모션캡쳐 시스템을 제안한다. 이 시스템을 통해 대상자의 자세 데이터를 취득하고, 취득한 데이터를 기반으로 특징을 추출하여 DB를 구축한다. 구축한 DB를 K-means 클러스터링 알고리즘을 이용하여 자세 학습을 수행한 후, 정상자세와 비정상자세를 분류한다. 관절의 회전각도, 위치정보, 분석정보를 이용하여 자세분류를 수행한 결과, 정상자세 판단 성공률은 99.79%로 나타났다. 이 결과로 미루어 4개 관절에 대한 특징을 이용하여 사용자의 자세를 판단 가능하며, 향후 척추질환 예방 시스템에 적용하여 사용자의 자세를 교정하는 데 도움을 줄 수 있을 것으로 판단된다.

• 한국전문물리치료학회지
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• 제21권3호
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• pp.11-19
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• 2014

The purpose of this study was to investigate the activity of the transverse abdominal muscle resulting from changed posture by measuring the thickness of the transverse abdominal muscle in a supine posture, a slouched sitting posture, and an erect sitting posture. The subjects of the study were 28 patients with cerebral palsy. All their transverse abdominal muscles at the end of inhalation were measured at supine, slouched sitting (S sitting) and erect sitting (E sitting) postures by using ultrasonography, and then their dynamic sitting balance was measured at S sitting and E sitting postures by using BioRescue. For the statistical analysis, the Kruskal-Wallis test and the Wilcoxon signed-rank test were used to compare the differences among each the postures. The results were as follows. The thickness of the transverse abdominal muscle when comparing the supine posture and the S sitting posture showed no statistically significant difference. But the E sitting posture showed a statistically significant difference as compared with the others. In addition, the dynamic sitting balance in comparing the S sitting and E sitting postures showed a significant difference. In conclusion, the E sitting posture has a more positive effect on postural control and balance than generally taking the S sitting posture, for the sitting posture of a patient with cerebral palsy. It is suggested that patients with cerebral palsy mainly experiencing a sedentary life or being in a wheelchair should be seated in the E sitting posture during their daily life, and it may be necessary to continue to monitor and manage the proper E sitting posture.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.459-464
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• 2004

The rifle impact of human body affected by the posture of human for rifling. The interaction human-rifle system influence the firing accuracy. In this paper, impact analysis of human model for shooting posture is carried out. ADAMS code and LifeMOD is used in impact analysis of human model and modeling of the human body, respectively. On the shooting, human model is affected by rifle impact during the 0.001 second. Performed simulation time for shooting is 0.1 second. Applied constraint condition to human-rifle system is rotating and spherical condition. As the results, the displacement of rifle and transfer path analysis of impact of human model is presented.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.123-124
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• 2019

In the labor-intensive construction site, potential threats of the musculoskeletal diseases mainly caused by various repetitive physical tasks, vulnerable environment, and the aging of the labor worker exist. However, quantitative measuring method of construction labor worker's work posture has not been improved yet. This study proposed musculoskeletal measuring method by using wearable motion recognition sensor for quantitative evaluation and analysis of working posture of construction workers. This method is expected to be used as a basic data for posture analysis and prevention construction safety accidents, as well as physical workload and labor productivity analysis by labor work type.