• 한국운동역학회지
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• 제23권2호
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• pp.99-108
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• 2013

The purpose of this study was to analyze the kinematic characteristics of javelin to compare the characteristics between world elite athletes and local male athletes. The subjects selected 9 athletes out of total 13 athletes recorded more than 65 m in the preliminary and main competition participated in the 93rd National Sports Festival held in 2012. Three-Dimensional motion analysis using a system of 4 video cameras(Sony HXR-MC2000) at a sampling frequency of 60 fields/s was performed for this study. The Kwon3D 3.1 was used to obtain the three dimensional coordinates about the top, grip, end of javelin. And the kinematic factors of javelin calculated using Matlab2009a program. The resultant speed of javelin that affects directly to the record of performance showed 26.08 m/s indicated lower speed of about 2-3 m/s than world elite athletes. The release point appeared to have been made at the high of $1.79{\pm}0.07$ m of 99.8% of the height of the athletes. In terms of release angle, it was indicated average $33.0{\pm}3.81^{\circ}$ lower release angle compared to the world elite athletes. The attitude angle(up & down tilt angle, X axis) related to javelin indicated average $38.5{\pm}4.96^{\circ}$, its related attack angle average $5.5{\pm}5.11^{\circ}$, and yaw angle(sideslip, side attack angle) average $15.7{\pm}8.48^{\circ}$.

• 한국운동역학회지
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• 제17권4호
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• pp.99-106
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• 2007

The gait instability in the elderly has been associated with age-related deterioration in physical strength and reducing the potential for elderly falls requires regular exercise. In 2005, National Center for Injury Prevention and Control(NCIPC) reported that most elderly falls occur during activities in daily living(ADL). To better reveal biomechanic mechanisms underlying age-related degeneration in gait stability, and to enhance the assessment of falls risk, an accurate quantification of a person's balance maintenance during locomotion is needed. Instantaneous orientation of the line connecting COP and COM can characterize whole body position with respect to the supporting foot during gait and the angle between this line and the vertical line passing through the COP known as a good assessment to detect the elderly gait instability. Therefore the purpose of this study was to investigate a 6-month walking exercise effects in reducing elderly fall risk factors by using COP-COM inclination angles. Twenty-two community-dwelling elderly participated this study. The participants performed a walking exercise(3 times/week, 1 hour/visit) for 6 months. Laboratory kinematics during walking was assessed at months 0, 3 and 6. Significant increased in gait velocity was found among periods(p=.011, $1.25{\pm}.03$, $1.32{\pm}.03$, and $1.39{\pm}.04\;m/s$ in 0-, 3-, and 6-month, respectively). Also, significant differences in anterior and posteriror inclination angles were found among the periods(p<.05; posterior inclination angles: $12.8{\pm}2.2$, $11.0{\pm}2.9$, & $10.9{\pm}1.9$; anterior inclination angles: $13.7{\pm}1.7$, $14.6{\pm}3.2$, & $1.46{\pm}.21$ in 0month, 3month, & 6month, respectively). These findings provide evidence of significant reduced fall risk factors of community-living older adults associated with a systematic walking program.

• 한국운동역학회지
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• 제27권1호
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• pp.67-74
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• 2017

Objective: The purpose of this study was to apply a general linear model in statistics to marker position vectors used to study human joint rotational motion in biomechanics. Method: For this purpose, a linear model that represents the effect of the center of hip joint rotation and the rotation of the marker position on the response was formulated. Five male subjects performed hip joint functional motions, and the positions of nine markers attached on the thigh with respect to the pelvic coordinate system were acquired at the same time. With the nine marker positions, the center of hip joint rotation and marker positions on the thigh were estimated as parameters in the general linear model. Results: After examining the fitted model, this model did not fit the data appropriately. Conclusion: A refined model is required to take into account specific characteristics of longitudinal data and other covariates such as soft tissue artefacts.

• 제어로봇시스템학회논문지
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• 제13권9호
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• pp.910-914
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• 2007

In this paper, an experimental study is performed to adjust position of compliance center of Elastomer Shear Pad Remote Center Compliance (ESP RCC) device, which is used on precise peg in hole process. In the study, variation of the lateral/axial stiffness of the ESP is proposed as a control parameter to adjust the position of compliance center of the ESP RCC. The variation of the stiffness of the ESP is achieved by controlling the shear stress of the ESP. To control the shear stress of the ESP, position of top side of the ESP is changed while remaining bottom side of the ESP is fixed on the RCC plate. To evaluate effect of the proposed idea, stiffness variations of the ESP on various shear stresses are measured, and variation of the compliance center is measured with the ESP RCC that can control the position of compliance center by using the shear stress. The measured data shows unique characteristics that have not been shown in other types of ESP VRCCs.

• 한국운동역학회지
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• 제21권2호
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• pp.231-241
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• 2011

The purpose of this study was to analyze the distribution of foot pressure generated by active materials of a functional insole. Comfort is an important consideration while selectingfootwear and insoles. Consequently, it has an influence on injury. The development of new materials for functional insoles is considered one of the more important points for their manufacture. The method adopted in this study is as follows. First, ten healthy males were selected as subjects for the study. Each subject's foof was pre-screened podoscope(Alfoots, Korea) to check for the presence of any foot abnormalities, Two kinds of equipment were used for the study: a foot pressure device from Pedar-X, Germany, and a treadmill from Pulsefitness, UK. Next, each subject was asked to test four types of insoles(insoles of outdoor shoes, indoor shoes, walking shoes, and sports shoes) via walking trials on the treadmill at a constant speed of 4.2 km/h. The pressure distribution data(contact area, maximum force, maximum peak pressure, and maximum mean pressure) was collected using the pressure device at a sampling rate of 100 Hz. Results of the tests showed that all four types of functional insoles increased contact areas whit the foot. Further, functional insoles of walking shoes and sport shoes decreased the foot pressure. From these results, we conclude that the active materials of functional insoles of shoes can increase the contact area and provide greater comfort.

• 대한견주관절학회:학술대회논문집
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• 대한견주관절학회 1997년도 학술대회
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• pp.121-125
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• 1997

• 한국실내디자인학회논문집
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• 제19권6호
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• pp.3-10
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• 2010

The purpose of this study is to examine the state of utilization in sport facilities at a university and drew up the improvement plan for all students. To accomplish this work, the survey of the 445 students(male 221, female 224) were collected. The collected data were analyzed through the frequency analysis. All of sports facility is used for wide range of student who like to use as their leisure in order to learn variety experience for spending their spare time. Also sports facility of university accomplish social education function to all member of university. Having sports facility for university can also work as a promotion and new impression to people its university image as well as welfare for staff. Especially, excellent sports facility at university can provide public service to local people where university is located. Having sport facility at university is directly related to development of university in many way, university is required to implement effective program for operating sport facility at university.

• 한국운동역학회지
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• 제24권3호
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• pp.209-216
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• 2014

The purpose of this study was to explore the effect of 8 weeks after school classes of track sports on students' start motion through kinematic variables. 30 students in D National university of education participated for this study. These students divided into two groups, 17 students for experimental group and 13 students for control group. The two groups participated in general athletic class as common class, and the experimental group participated in after school class additionally. The general class taught track and jump skill for 3 hours a week, and the after school class taught only athletic running skill for 30 minutes a week. Pre and post test assessed to assess students' kinematic changes. Findings indicated that velocity and step rate were increased, and contact time, step length, displacement of center of mass were decreased in the experimental group. In the control group, early velocity, knee/hip angle velocity were increased, and contact time, step length, displacement of center of mass were decreased. In conclusion, the students who only participated in general class, could not maintain athletic skills obtained from the class. However, students who participated in both general and after school class accomplish athletic start skill. This is because Continuous learning effect helped students keep the skill and did not lose the skill. Thus, in order for students to learn specific sport skills, joining after school class with general class together is recommended.

• 한국운동역학회지
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• 제23권1호
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• pp.1-9
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• 2013

The purpose of this study was to provide information on athletes' characteristics and advantages and disadvantages by analyzing the kinematic factors having a decisive influence on competitive abilities such as release conditions in the delivery phase on major Korean javelin athletes. Two supported javelin throwers of the Korean national team participated in this study. The total average time required of the delivery phase was 0.31(${\pm}0.016$). The athletes' release angle was 33.2 to 41.7 degrees. The attack angle varied widely from -3.5 to 5.9 degrees. The Javelin heights of Subject A and B were 95.9 and 89.2%Ht. The average stride length were 180.6 and 176.7cm. The center of mass velocity of LFD and REL was relatively low in all the subjects. The average deceleration rates of center of mass velocity of Subject A and B were 57.2 and 48.9%lose. The left knee angles of Subject A and B were 160.1 and 155.5 degrees in LFD, 153.0 and 164.0 degrees in REL. The joint velocity of upper limb segments was relatively low in all the subjects. The maximum average wrist velocity of Subject A and B was 18.2 and 16.3 m/s in REL.

• 국제물리치료학회지
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• 제9권4호
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• pp.1657-1662
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• 2018

This epidemiological study aims to determine the incidence, areas, severity, and time of occurrence of sports injuries in elite female rowing athletes who were training at the Jincheon National Training Center for a 1-year period from January 1st to December 31st, 2017. According to the daily injury reports form of the IOC, sport events, weight division, injured area, and cause of injury were recorded, and the following results were found. Upon comparing the incidence of sports injuries, there was a significant difference in weight of double scull athletes. In terms of sports, there was a significant difference between pair and athletes who played double skull. Injuries occurred most commonly in the lower extremity (40.5%), followed by the trunk (35.1%), upper extremity (24.3%). for all athletes in rowing. The knee and lumbar spine/lower back were the most common injury sites. More than 60% of all injuries were Level III, and injuries occurred most frequently during training, followed by weight training and then competition.