• Physical Therapy Rehabilitation Science
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• 제1권1호
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• pp.13-16
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• 2012

Objective: Electroencephalogram (EGG)-feedback is a training procedure aimed at altering brain activity, and is used as a treatment for disorders like attention. The purpose of this study was to determine the effects of external focus of attention by EGG-feedback on balance in young adults. Design: Cross-sectional study. Methods: Subject were students in Sahmyook University. Fifty young adults in their twenties and thirties. Subjects were performed both with and without external focus of attention by EEG-feedback on the posture of standing and tandem standing. Participants were educated effort to maintain static posture when they were under internal focus of attention. Good Balance System was used for measurement of postural consistency upon the following force platforms. Results: Body sway decreased significantly both normal standing and tandem standing with external focus of attention by EEG-feedback (p<0.05). Conclusions: The results demonstrate that the benefits of an external attentional focus are generalizable to young adults. The external focus of attention outperformed the internal focus of attention on the postural balance (p<0.05). It is showed that external focus of attention significant effects on balance by revoked automatic postural control of movement. Furthermore balance might be improved by training with an external focus. Further study is required to develop for training as a method of preventing fall in elderly peoples.

• 한국전문물리치료학회지
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• 제18권4호
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• pp.51-59
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• 2011

The purpose of this study was to investigate the effect of attentional focus and distance of external focus on the performance of balance task of upper extremity. Subjects (N=30) held a stick (2 m) and maintained it horizontally. All of the subjects performed balance task of upper extremity under four different attentional focus conditions: focus on hand (internal focus), marker at 10 cm inside of hand (external focus 1), marker at 10 cm outside of hand (external focus 2), marker at 20 cm outside of hand (external focus 3). The mean velocity of the bar (mm/s) and the muscle activity of biceps brachii (%RVC) were measured. They were decreased when the subjects focused on external focuses compared to internal focus and decreased as distance of attentional focus from body increased (p<.05). There were significant differences between groups (p<.05); internal focus-external focus 1, internal focus-external focus 2, internal focus-external focus 3, external focus 2-external focus 3. These results showed that external focus is more effective than internal focus in enhancing motor performance and focusing on more distant attentional focus results in enhanced motor performance promoting the utilization of more automatic control mechanisms.

• The Journal of Korean Physical Therapy
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• 제33권1호
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• pp.1-6
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• 2021

Purpose: This study examined the effects of heel insoles on the static balance and leg muscle activity and posture control strategy during external perturbation. Methods: Thirty healthy young men participated in the study. The subjects underwent two experimental conditions: 1) no heel insole condition (0cm) and 2) wearing heel insole condition (5cm). The static balance was measured using an I-Balance device, which measured the change in the center of gravity (COG). The onset time of muscle activation and muscle activation of the erector spinae (ES), hamstring (HAM), gastrocnemius (GCM) were measured using surface EMG electrodes to determine the change in posture control strategy during external perturbation. Results: The speed and distance of COG were significantly higher in the wearing heel insoles condition than the no heel insole condition (p<0.05). In addition, significant differences in the onset time of the GCM, HAM, and ES muscle activation were observed when there was no heel insole condition during external perturbation (p<0.017). On the other hand, no significant differences in the onset time of muscle activation were observed between GCM and HAM when wearing the heel insole condition during external perturbation (p<0.017). Moreover, muscle activation of the GCM was significantly higher in the wearing heel insoles condition than the no heel insole condition during external perturbation (p<0.05). Conclusion: These findings suggest that heel insoles may have disadvantages, and increased efforts are needed to maintain balance and change the posture control strategy during external perturbation.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 추계 학술대회논문집
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• pp.102-105
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• 2003

The effect of the external balance strut on the wind tunnel model is investigated with simplified geometries. For this study, flat plate and elliptic wing are simulated with and without a cylinder. Pressure and wall shear stress distribution are analyzed to understand the effect of the cylinder.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제11권3호
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• pp.197-207
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• 2007

Based on a survey on 1620 students in primary school and secondary school., by adopting Eysenck Personality Questionnaire (EPQ), we got the following findings : 1. There is close relationship between emotionality characteristics of temperament and mathematics academic achievement of the subjects at Grade 5 (Primary 5), Grade 8 (Junior Secondary 2), and Grade 10 (Senior Secondary 2). Also there is close relationship between internal-external directivity characteristics of temperament and mathematics academic achievement at Grade 5 and Grade 8. While there is not close relationship between internal-external directivity characteristics of temperament and mathematics academic achievement at Grade 10; 2. There is close relationship between temperament types and mathematics academic achievement of the subjects from the three grades. Superior temperament, which benefit learning mathematics, are sanguine, sanguine-phlegmatic and phlegmatic; While inferior temperament types, which don't benefit learning mathematics, are choleric, melancholic and choleric-melancholic. With the rising of grade, temperament types of benefiting learning mathematics converts from external directivity emotion balance to balance of internal-external directivity emotion stability. While temperament of no benefiting learning mathematics converts from internal directivity emotion balance to balance of internal-external directivity emotion instability; 3. In mathematics education, students' temperament difference, which affects learning mathematics, should be recognized. Mathematics teachers should find out the best teaching ways, forms and methods which are suitable for student's temperament type, so that the students with different temperament types can gain better mathematics academic achievement.

• International Journal of Aeronautical and Space Sciences
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• 제1권2호
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• pp.68-74
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• 2000

A comparative wind tunnel testing of an airplane model was performed at the Korea Aerospace Research Institute Low Speed Wind tunnel(KARI LSWT). The model used for the comparative test was a seaplane model from the Glenn L. Martin Wind(GLM) Tunnel of University of Maryland, U.S.A. The 6-component external balance used in force and moment measurement is pyramidal type, which is a precision device that has strain gauge-type load cell inside of balance and the virtual center of the balance coincides with the tunnel centerline. Image method is adopted to eliminate the tare and interference of the model support, and to correct the flow angularity to the model also. Test results from KARI LSWT were compared with the results from GLM tunnel.

• 한국운동역학회지
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• 제33권2호
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• pp.62-72
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• 2023

Objective: Although balance training has been used as an effective ankle injury rehabilitation program to restore neuromuscular deficits in patients with chronic ankle instability, it is not effectively used in terms of motor learning. Attentional focusing can be an effective method for improving ankle kinematics to prevent recurrent ankle injuries. This study aimed to 1) evaluate the effects of attentional focus, including internal and external focus, and 2) determine a more effective focusing method for patients with chronic ankle instability to learn balance tasks. Method: Twenty-four patients with chronic ankle instability were randomly assigned to three groups (external focus, internal focus, and no feedback) and underwent four weeks of progressive balance training. The three-dimensional ankle kinematics of each patient were measured before and after training as the main outcomes. Ensemble curve analysis, discrete point analysis, and post hoc pairwise comparisons were performed to identify interactions between groups and time. Results: The results showed that (1) the external focus group was more dorsiflexed and everted than the internal focus group; (2) the external focus group was more dorsiflexed than the no feedback group; and (3) the no feedback group was more dorsiflexed than the internal focus group. Conclusion: Because dorsiflexion and eversion are ankle motions that oppose the mechanism of lateral ankle sprain, using the external focus method during balance training may be more effective in modifying these motions, thereby reducing the risk of ankle sprain.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.161.2-161
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• 2001

To achieve a cooperative work between human and robot, it is thought helpful to estimate the states of human mind, which originates his behavior. In this paper, human mind was considered to modify instinctive desires according to the conditions of external world surrounding the instinct. A simple human mind model was designed so that it finds a balance between instinctive desire and restriction from the external world. The external world is divided into three sub-worlds like subject´s whole body, its partner and concerned periphery. Proposed mind model has three-layers construction. Each of the layer tries to find a balance between desire and restriction from external world. In each layer, the role of finding the balance was expressed by an identical optimal control minimizing a performance index function of quadratic form with a weight factor, which is rearranged and named ...

• The Journal of Korean Physical Therapy
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• 제27권4호
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• pp.196-200
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• 2015

Purpose: The purpose of this study was to examine the muscle activity of the trunk muscles during balance exercises on a stable and unstable surface in patients with stroke. Methods: Thirteen subjects (8 males, 5 females) with stroke were enrolled in the study. Muscle activity was recorded using surface EMG electrodes from the affected side of the erector spinae, external oblique, and internal oblique muscles. The exercise was performed under three conditions. For the first condition for balance exercise, subjects were instructed to sit on an exercise mat with legs extended. The second condition was to sit with legs extended, with a balance pad under their buttocks. The third condition was to sit with legs extended, have a balance pad under the buttocks and a balance cushion under the lower legs. Results: This study showed significant differences in EMG activities during both arm lifting exercise and weight shifting exercise between conditions. This study showed that the EMG activities of the erector spinae, external oblique, and internal oblique muscles were significantly higher when the trunk exercise was performed using the balance pad with balance ball than when using the stable surface. Conclusion: In conclusion, performing balance exercises using an unstable surface is a useful method for facilitating trunk-muscle strength and hence trunk stability.

• The Journal of Korean Physical Therapy
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• 제30권4호
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• pp.146-150
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• 2018

Purpose: This study aimed to investigate the effect of active vibration exercise on trunk muscle activity, balance, and activities of daily living in patients with chronic stroke. Methods: Twenty-four patients with chronic stroke were randomly assigned to an experimental (n=12) or a control (n=12) group. The experimental group performed an active vibration exercise workout for 20 minutes a day five times a week for 4 weeks using a flexi-bar. Trunk muscle activity was measured using surface electromyography. Balance was measured using the Berg balance scale. Activities of daily living were measured using the functional independence measure. Results: The intragroup comparison showed significant differences in the rectus abdominis, internal oblique, and external oblique muscle activity values, Berg balance scale score, and functional independence measurement values in the experimental group. The intergroup comparison showed that differences in the rectus abdominis and internal oblique external oblique muscle values, Berg balance scale score, and functional independence measurement value for the experimental group were significantly related to those in the control group. Conclusion: Based on these results, this study proved that the active vibration exercise effectively improved trunk muscle activity, balance, and activities of daily living in patients with chronic stroke.