• Journal of Institute of Control, Robotics and Systems
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• v.11 no.1
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• pp.58-66
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• 2005

Usual human gait can be modeled as continual impact phenomenon that happens due to the topological change of the kinematic structure of the two feet. The human being adapts his own control algorithm to minimize the ill effect due to the collision with the environment. In order to operate a Humanoid robot like the human being, it is necessary to understand the physics of the impact and to derive an analytical model of the impact. In this paper, specially, we focus on impact analysis of the kicking motion in playing soccer. At the instant of impact, the external impulse exerted on the ball by the foot is an important property. Initially, we introduce the complete external impulse model of the lower-extremity of the human body and analyze the external impulses for several kicking postures of the lower-extremity. Secondly, a trajectory-planning algorithm of a ball, in which the initial velocity and the launch angle of the ball are calculated for a desired trajectory of the ball, will be introduced. The aerodynamic effect such as drag force and lift force is also considered. We carry out numerical simulation and experimentation to verify the effectiveness of the proposed analytical methodology.

• Journal of the Ergonomics Society of Korea
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• v.36 no.2
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• pp.69-86
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• 2017

Objective: The present study is intended to develop an improved bus seat armrest design by evaluating various bus armrest designs from ergonomic aspects. Background: An ergonomic armrest design which considers the sitting postures and body shapes of passengers can improve the convenience and comfort of a bus seat. Method: Subjective satisfaction of each of five design dimensions (length, width, height from seatpan, shape, and angle) was evaluated for seven bus seat armrest designs in various sizes and shapes by 58 participants (28 males and 33 females) using a 7-point scale (1: very dissatisfied, 4: neutral, and 7: very satisfied). Improved bus seat armrest designs adjustable in length and rotatable to the left or right (sliding and rotating armrest, SRA) with a concave, flat, or convex shape of the upper part were developed by considering the preferred design features and the body size and shape in sitting posture and needs of passengers and then compared with a conventional armrest. Results: A bus seat armrest with a wide width (40~50mm), a long length (360mm), a lower height (213mm), and a curved shape was found significantly preferred in terms of comfort. The proposed armrest designs (SRA-convex, SRA-flat, and SRA-concave) improved satisfaction by 46~62% for length suitability, 184~216% for width suitability, 205~214% for angle suitability, 138~181% for contact area suitability, and 49~64% for height suitability, 138~174% for comfort, and 93~111% for overall satisfaction. Conclusion: The preferred design features and passengers' needs of bus seat armrest were identified and the SRA designs were recommended for better usability. Application: The ergonomic design process of bus seat armrest employed in the present study can be applied to designing armrests in various vehicles for better convenience and comfort.

• Physical Therapy Rehabilitation Science
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• v.10 no.3
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• pp.244-250
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• 2021

Objective: The purpose of this study was to investigate the effect of sprinter pattern bridging exercise using theraband on activation of lower extremity and abdominal muscle and to find out postures that can effectively improve abdominal and lower extremity muscle strength and increase abdominal stability. Methods: This study was designed as a cross-sectional study. The following research was done with applicants attending S university in Seoul to compare the difference in muscle activity between one-leg-Support bridging exercise and sprinter-pattern bridging exercise using theraband. For 48 study participants, we first measured their MVC. Then, we applied one-leg-support bridging exercise and sprinter-pattern bridging exercise at random order. These data were expressed as the percentage of maximal voluntary contraction (%MVC).Electromyography analysis was performed by measuring the external obliques, internal obliques, biceps femoris, and gluteus maximus. Results: There was a statistically significant increment of muscle activity in external and internal oblique muscle(p<0.001)by sprinter-pattern bridging exercise using theraband. On the lower body, statistically significant increment of muscle activity in biceps femoris and gluteus maximus was found(p<0.05). On the other hand, on erector spinae, there was statistically significant decrease in muscle activity(p<0.05). Conclusions: Efficient treatment is expected when sprinter-pattern bridging exercise using theraband is applied clinically.For patients with chronic knee and ankle pain who have difficulty bearing weight, including low back pain and internal rotation of the femur, starting with a low weight bearing, we think it will be helpful in planning systematic training aimed at progressively strengthening the lower extremities.

• Korean Journal of Applied Biomechanics
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• v.13 no.1
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• pp.155-171
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• 2003

The purpose of this study was to analyze the kinematic variables of over head kick(OHK) in soccer with three dimensional analysis technique and show the kinematic characteristics of it. The 7 subjects were university football player who have been playing football more than 7 years. The OHK was filmed on 16mm video camera(30frame/sec.) kinematic variables were temporal, postures, and COG(center of gravity). The mean values and the standard deviation for each variables were obtained and used as basic factors for examining characteristics of OHK. The results of this analysis were as follows : Temporal variables : The total time elapsed(TE) of OHK was $0.95{\sim}1.14sec$, the 1st phase was 0.35sec., 2nd phase was 0.46sec., and 3rd phase was 0.22sec.. Posture variables : When subjects performed OHK at the impact event, the ankle and knee angle of kicking foot were more extend than supporting foot. but the hip angle of supporting foot were more extend than kirking foot. Moving distance of the center of mass of the both foot. When subject performed OHK at the impact event, the range of distance on mediolateral direction aspect into right left shoulder line, anteroposterior direction aspect was $20.9{\pm}10.5cm$, vertical direction aspect was $92.3{\pm}19.9cm$. Angular velocity : the faster angular velocity of knee ankle on the kicking foot pew form jump position to landing position, the faster velocity of ball became. C. O. G. variables. When subject performed OHK at the impact event, upper part of the body was getting lower, lower part of the body was getting higher.

• Journal of Society of Preventive Korean Medicine
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• v.26 no.3
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• pp.87-96
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• 2022

Objective : We examined the literature of <Life Nurturing Method and Conduction Exercise(養生方導引法)> of 《Pathogenesis and Manifestations of Food Stagnation and Indigestion(宿食不消病諸候)》 in 『Treatise on the Pathogenesis and Manifestations of All Diseases(諸病源候論)』 and actually implement its movement to present conduction exercise based on the principle of Korean medicine treatment. Method : We used web services for traditional Eastern Asian medical classics and some literature on 『Treatise on the Pathogenesis and Manifestations of All Diseases(諸病源候論)』 and its <Life Nurturing Method and Conduction Exercise(養生方導引法)〉. The original text was interpreted and the movements of <Life Nurturing Method and Conduction Exercise> were implemented according to the literature. A qi-gong(氣功) expert demonstrated the movements and we took pictures. Results : <Life Nurturing Method and Conduction Exercise(養生方導引法)> was written in the symptom of Food Stagnation and Indigestion(宿食不消候) and the symptom of food damage and excessive eating(食傷飽候) among the chapters of 《Pathogenesis and Manifestations of Food Stagnation and Indigestion(宿食不消病諸候)》. With respect to the movements and breathing, stretching your back allows qi(氣) energy to enter the lower cinnabar field(下丹田) immediately, and when the lower stomach is full of qi it can be transported upper body, leading to better communication of qi around the body. Conclusion : The practical implementation of the movements and postures will contribute to understanding the characteristics, pathology, and contents of diseases related to indigestion, and furthermore it can be widely used clinically for prevention and treatment of digestive disorders.

• Journal of the Korea Convergence Society
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• v.12 no.3
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• pp.165-176
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• 2021

Recently, interest in home training and changes in lifestyle are expanding the market in the healthcare field, and high value-added fashion products reflecting the dumbbell economy phenomenon are being released. This study had the following objectives: to investigate the possibility of developing a fashion item that can be applied to the dumbbell economy phenomenon; to develop the UI/UX of a smartphone application for beginners who wish to work out their upper and lower bodies regardless of time and space; and to create a wearable customized smart athleisure fashion device. First, the study identified factors related to exercise methods, breathing techniques, and range of exercises for beginners by investigating the postures of workouts of the upper and lower bodies by angles. Based on the results, the study collected empirical data through a user needs analysis from muscle strengthening exercise experts to verify the significance of the study and use as fundamental data. Second, the study developed the UI/UX of a smartphone application with three different contents: counting, suggesting exercise postures, and providing exercise calendars. Further, the study analyzed necessary user-centered concepts and characteristics in terms of design and technology and developed a wearable customized smart athleisure fashion device based on the results.

• The Journal of Korean Physical Therapy
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• v.36 no.2
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• pp.71-77
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• 2024

Purpose: The prolonged use of digital devices has led to the widespread adoption of poor postures, particularly rounded shoulder posture (RSP), associated with shoulder impingement and pain. This study investigates the effects of neuromuscular electrical stimulation (NMES) on RSP in healthy adults. Methods: Thirty adults with RSP were randomly assigned to NMES only, exercise only, or NMES with exercise groups. NMES was applied to the lower trapezius, which was the target muscle in this study, for a total of 2 weeks, 5 times per week, 20 minutes per session. The exercise program included pectoralis minor stretching, wall-slide exercise, dynamic hug exercise with band, and Brugger stretching for upper body with band, which were performed for a total of 2 weeks, 5 times per week, 20 minutes per session. Outcome measures, including the Supine Method (SM) for posture and surface electromyography (EMG) of the lower trapezius for muscle activity, were assessed before the intervention, after 5 sessions, and after 10 sessions. Results: All the groups showed significant changes in the SM and % maximal voluntary isometric contraction (%MVIC) over time (p<0.05). The NMES group had significantly reduced SM at 1 week, while the exercise and combined groups had reduced SM at 2 weeks (p<0.017). All the groups had increased %MVIC at 2 weeks (p<0.017), with no significant differences observed between groups. Conclusion: NMES alone can be as effective as exercise in improving RSP. NMES combined with exercise also showed positive outcomes, thus offering diverse treatment options for this condition.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.3
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• pp.171-181
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• 2009

This study was carried out to evaluate a musculoskeletal symptom and the work posture of the nurses in an operating room who have worked in the present department for more than one year. The job analysis of operating room nurses for ergonomic work posture analysis is divided into 14 tasks. On the basis of that, a survey research and ergonomic work posture analysis are also carried out. Among 41 operating room nurses of a cancer center in Kyonggi province who responded to the self-administered questionnaire, 20 nurses were observed and videorecorded to apply Rapid Entire Body Assessment(REBA) to ergonomic work posture analysis from April 16, 2007 to May 18, 2007. The results of analysis are as follows. The prevalence rate of musculoskeletal symptoms was 75.6% and its prevalence rates by part of the body are these followings; lower back and leg/foot 43.9%, shoulder 36.6%, neck 34.1%, hand/wrist/ finger 22.0%, arm/elbow 14.6%. In accordance with the results of ergonomic work posture analysis, 4 tasks that have a REBA score of 8 have high-risk levels and require an immediate management. It shows there is a significant correlation with overall musculoskeletal symptoms and objective workloads that are estimated by REBA. In conclusion, the work conditions of operating room nurses should be improved. It is also necessary that inappropriate work postures and ergonomic work conditions are improved to prevent musculoskeletal disorders of operating room nurses.

• Journal of TMJ Balancing Medicine
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• v.7 no.1
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• pp.11-16
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• 2017

In order to understand Changeologically on the meaning of FCST's TMJ (temporo-mandibular joint) treatment procedure, Yi, Shike, Bi, Gen trigrams concerning the jaw and change by treatment were analyzed from the viewpoint of semiotic context of hexagon and holistic interpretation on disease. Yi is meant by jaw but actually indicates mouth made by maxilla and mandible, and it's characters are related with nourishing by aliment and words. But when we eat and speak in the daily life, jaw does not nourish properly it's own body by bad habit or postures. For the treatment of this ill state, there needs punishment and correction symbolized with Shike. Shike has fourth nine meaning obstacles between the two strong lines in the upper and lower end, and so it has the function of mastication and get rid of the fourth nine metaphorically indicating subluxation of axis using CBA and auxiliary measures of four movement or laughing methods. Bi expresses the achievement and effects of consecutive mastication process implicating normalized manifestation of jaw and its linked spinal function. Gen symbolizes removing selfish motive or partiality in advance and reaches the best state of the saint righteously self-nourishable human being.

• Journal of the Korea Safety Management & Science
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• v.17 no.3
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• pp.133-141
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• 2015

This study tried to identify the problems associated with the posture to be analyzed and tried to suggest guidelines for MSDs(Musculoskeletal Disorders) evaluation based on working posture. A total of 50 jobs from 3 different types of industries(electronics, hospitals, automobiles) were used for MSDs evaluation study which was done by 6 observers. Two indexes were applied to identify the problem in this study which were percentage of agreement and counter-time-error rate. Specifically, 'counter-time-error rate' represented a degree of consistency in terms of selecting the posture to be analyzed time after time. Main results of the study were as follows; 1) The average percentage of agreement for representative posture for whole body was relatively higher than that for representative postures for individual body parts, 2) The counter-time-error rate(%) has been reduced as the evaluation process has repeated for the same job. 3) The counter-time-error rate(%) for electronics, hospitals, and automobiles were 63.4%, 61.2%, and 67.3% respectively. 4) The counter-time-error rate(%) for the job with the work cycle of 0.5 to 2 minutes were lower than that of the jobs with the work cycles less than 0.5 minute or greater than 2 minute. 5) The work cycles and the number of trials had significant effects on counter-time-error rate while the types of industries did not have significant effects on counter-time-error rate. Some guidelines could be prepared from the results of the study. Probably, there should have an extension in terms of form and matter for this study in order to have more practical output.