• Journal of Korean Elementary Science Education
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• v.40 no.1
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• pp.1-12
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• 2021

This study investigated pre-service elementary teachers' understanding of the planetary revolution movement of Mars and their explanatory models to show how the Sun-Earth-Mars system worked. An assessment item set using five celestial maps drawn from the Stellarium was designed to probe pre-service teachers' understanding of the prograde-retrograde motion of Mars. Among 23 participants, only four showed scientifically accurate understanding of Mars movement and drawing correct explanatory models for the planetary movement. Even the pre-service teachers who construed correctly prograde and retrograde motions of Mars showed a clockwise movement model due to their intuitive perceptions of Mars movement data from the celestial maps. Pre-service teachers with poor understanding of planetary movement also showed weak explanatory models due to their limited observation or lower spatial thinking. Although the planetary motion is not an easy topic for pre-service elementary teachers, it can be argued if the alternative approach, such as using appropriate observational data of a planet and changing the frames of reference between Earth-based view and Space-based view, is employed effectively in teaching planetary motion, pre-service teachers can reach the upper level of leaning planetary motion in terms of the planet's revolution.

• Korean Journal of Applied Biomechanics
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• v.17 no.2
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• pp.187-196
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• 2007

The purpose of this study was to find the most effective movement pattern from three different types of preparatory movement(squat, countermovement and hopping) in sideward responsive propulsion task, which had the time constraint to complete the performance. 7 healthy subjects participated in left and right side movement task by an external signal, which required the subject to perform the task as fast as possible. Mechanical output and joint kinetics focusing on the lower extremities were analyzed. The results were as follows. In spite of the shortest duration in propulsive phase, the hopping condition showed no difference with other conditions in the work output done and take-off velocity. It resulted from the greatest power output generated during the propulsive phase. A significant difference was found for joint moment and joint power according to the movement conditions. The joint moment and joint power for the countermovement and hopping conditions were larger than those in the squat condition. This was speculated to be due to the extra power that could be generated by the pre-stretch of muscle in preparation for the propulsion. The hopping condition which had substantially more pre-stretch load in the preparatory eccentric phase produced considerably more power than countermovement condition in the propulsive concentric phase. Furthermore during the hopping a large amount of joint moment and joint power could be produced in a shorter time. Therefore it was deemed that the hopping movement is an effective type of preparatory movement which takes much more advantage of the pre-stretch than any other movement.

• Korean Journal of Applied Biomechanics
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• v.15 no.3
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• pp.9-19
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• 2005

The purpose of this study was to analyze the effects of three different types of preparatory movement(squat, countermovement and hopping) in sideward responsive propulsion movement. 7 healthy subjects performed left and right side movement task by external output signal. 3D kinematics were analyzed The results were followed First, performance time in the countermovement and hopping conditions was shorter(10-20%) than that in the squat condition. The hopping condition that is more related to pre-stretch showed excellent performance. Second, time difference between after turned on the external signal and until take off was the primary factor in performance results among movement conditions. The preparatory phase before the propulsive phase in the squat condition produced more time than that in other conditions. The hopping condition showed the most short time in both the preparatory and the propulsive phase, therefore it was advantage for performance result Third, significant difference was not found in take-off velocity among movement conditions although there was difference of the time required in the propulsive phase. The maximum acceleration in the propulsive phase was larger in order of the hopping. countermovement, and squat condition. The countermovement and hopping conditions showed high take-off velocity although the propulsive phase in those conditions was shorter than that in squat condition. The pre-stretch by preparatory countermovement was considered as the positive factor of producing power in concentric contraction. Fourth, the hopping condition produced large angular velocity of joints. In hopping condition, large amount of moment for rotation movement was revealed in relatively short time and it was considered to cause powerful joint movements. In conclusion, the hopping movement using countermovement is advantage of responsive propulsion movement. It is resulted from short duration until take off and large amount of joint moment and joint power in concentric contraction by pre-stretch.

• Physical Therapy Korea
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• v.23 no.1
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• pp.80-86
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• 2016

Background: Prone hip extension (PHE) can be performed to measure the lumbopelvic motor patterns and motions. Imbalances in lumbopelvic muscle activity and muscle weakness can result in instability including pain in lumbopelvic region. The posterior oblique sling (POS) muscles contribute to dynamic lumbopelvic stability. In addition, POS are anatomically aligned with the trapezius muscle group according to shoulder positions. Objects: This study compared the electromyography (EMG) activity of POS and pelvic compensations during PHE with and without pre-activation of lower trapezius muscle (lowT). Methods: Sixteen healthy males were recruited. PHE was performed in randomized order: PHE with and without lowT pre-activation. Surface EMG signals were recorded for biceps femoris (BF), gluteus maximus (GM) (ipsilateral), lumbar multifidus (MF) (bilateral), and the lowT (contralateral). An electromagnetic tracking motion analysis was used to measure the angle of pelvic rotation and anterior tilting. Results: The ipsilateral GM and bilateral MF EMG amplitudes were greater during PHE with lowT pre-activation compared to PHE without lowT pre-activation (p<.05). The BF amplitude during PHE without lowT pre-activation was significantly greater than that during PHE with lowT pre-activation (p<.05). The angles of pelvic rotation and anterior tilting during PHE with lowT pre-activation were significantly smaller compared to PHE without lowT pre-activation (p<.05). Conclusion: PHE with lowT pre-activation, which is aligned with the POS, showed more increased MF and GM muscular activity with smaller lumbopelvic compensations in rotation and anterior tilting compared to PHE without lowT pre-activation.

• Korean Journal of Childcare and Education
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• v.14 no.2
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• pp.19-38
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• 2018

Objective: This study explores how pre-service teachers' knowledge changed in the field of movement education and the characteristics of the instruction they perceived during a 15-week course. Methods: The drawing of concept maps and interviews were used to discuss how pre-service teachers' knowledge changed and the characteristics of the course. Results: The results showed that the pre-service teachers interrelated concepts in a more systematic way, and the concepts they used were increased while master concepts were decreased, indicating that their knowledge changed in a far more hierarchical order after the class. Characteristics of the course that led to a change in their knowledge appeared under the proper guidance of a professor. This was well demonstrated by feedback and evaluation at the stage of planning instruction and simulation teaching. Conclusion/Implications: The study demonstrated that the proper guidance of a professor was a useful tool for fostering the professional development of pre-service teachers in regard to constructing knowledge in movement education.

• Korean Journal of Applied Biomechanics
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• v.24 no.1
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• pp.1-9
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• 2014

The purpose of this study was to investigate the muscle mechanical properties of the pelvic axial pre-rotational movement for the Jireugi in the Taekwondo Juchumseogi stance. Eleven elite Taekwondo Poomsae athletes participated. Each participant performed 5 right hand Jireugi in Juchumseogi stance as fast and strong as possible while their motion was recorded by a 3D motion analysis system and the ground reaction forces by two force plates. The power and work of the muscular group surrounding the waist were analyzed to verify the effect of the stretch-shortening cycle (SSC) theory. The cause of the greater power seems to be the application of the SSC by the muscles surrounding the waist during the preparation phase of the pre-rotation group. For the none pre-rotation group, they only used the concentric contraction of the muscles surrounding the waist. Because the pre-rotation group used the SSC theory, they had the effect of shortening of the range of movement, creating a fast and more powerful rotation, thus anticipating the increase the magnitude of impact.

• The Journal of Korean Physical Therapy
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• v.28 no.5
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• pp.303-307
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• 2016

Purpose: This study was conducted to determine the effects of Mulligan's mobilization with movement (MWM) on changes in the talofibular interval in the sagittal plane in subjects with chronic ankle instability (CAI). Methods: Sixteen subjects with chronic ankle instability participated in this study. The talofibular intervals were measured from US images, and the weight-bearing lunge test was used to assess dorsiflexion of the ankle joint. Each dependent variable were measured on the both affected side and sound side in three trials in pre- and post-MWM. Dependent variables were examined with a two-way mixed-design analysis of variance (ANOVA). The two factors were side (sound side versus affected side) and intervention (pre- versus post-intervention). For post hoc analysis, paired t-tests were performed to compare the dependent variables. A p<0.05 was considered to indicate significance. Results: Dorsiflexion and talofibular interval differed significantly pre- and post-intervention (p<0.05). Post-hoc analysis revealed that the talofibular interval post-MWM was significantly less than that pre-MWM on the both the affected and sound side (p<0.05). The ankle dorsiflexion in the post-MWM group was significantly greater than that in the pre-MWM group on the affected side and the sound side (p<0.05). Conclusion: The Mulligan's MWM decreased the talofibular interval in subjects with CAI. These findings suggest that the MWM technique can change the position of the talus relative to the fibular in the weight bearing position.

• Journal of the Korean Society of Earth Science Education
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• v.13 no.3
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• pp.211-225
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• 2020

The purpose of this study was to investigate and analyze pre-service teachers' eye-movement in science textbooks in the learning process, whether they perceived "arrow" presented in textbooks, and changes in eye-movement by arrows. For the study, an eye-tracker, a eye-movement tracking device, was used, and 10 pre-service teachers attending a teacher training college were selected and conducted. The science textbook unit used in the research was the "Weather and Our Life" unit, one of the areas of earth science. As a result of the study, first, it was investigated that pre-service teachers devote more time to texts rather than illustrations in the learning process of science textbooks. Second, it was analyzed that pre-service teachers did not pay attention to the "arrow" presented in science textbooks. Third, it was confirmed that in order for "affordance of the eye-movement by arrow" to occur, sufficient concentration on "arrow" should be made. These findings suggest the importance of the learner's visual attention to learning elements in science textbooks such as "arrow". In addition, it suggests the importance of developing a textbook editing design that can induce visual attention to learning elements in textbooks through eye-movement research data for effective learning.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.4
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• pp.412-420
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• 2000

A treatment should be functional, esthetic, conservative and periodontally healthy in order to meet criteria of an ideal dental procedure. In a prsthodontic patient with horizontal and/or vertical space deficiency, orthodontic tooth movement should be considered as a pre-prosthetic procedure. With a conventional technique, orthodontic treatment is a time-consuming and uncomfortable procedure. Pre-prosthetic orthodontic treatment, however, is no longer difficult procedure with the help of recently developed techniques, such as passive bracketing. The present article outlines the problems and causes of horizontal and vertical space deficiency in prosthodontic patients, and presents efficient pre-prosthetic orthodontic treatment modalities with typical clinical cases.

• The Journal of Korean society of community based occupational therapy
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• v.3 no.2
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• pp.25-32
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• 2013

Objective : The purpose of this study was to investigate the effect of the ankle movement and the balance when the elderly conducted self-exercise with ankle movement control device through visual feedback. Method : This case-study included pre-test and post-test. The elderly women aged 80 did self-exercise for 20 minutes both morning and afternoon every day. The pre-test and post-test was conducted tracking test for evaluating ankle control movement and running time measurement of standing on one foot and Timed up-And-Go test for balance. Result : The subject improved the ankle control movement on tracking test and improved the balance in running time measurement of standing on one foot. But, Timed up-And-Go test was no change. Conclusion : The self-exercise with device of ankle movement control through visual feedback improved the ankle control movement and the balance for elderly.