• The Academic Congress of Korean Shoulder and Elbow Society
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• 2006.03a
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• pp.75-75
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• 2006

• Korean Journal of Applied Biomechanics
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• v.30 no.1
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• pp.1-6
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• 2020

Objective: The incidence rate of elbow ulnar collateral ligament injuries is dependent on the throwing speed or pitching type, especially in adolescent baseball players. However, mixed results have been reported due to a lack of controlled biomechanical analysis. Thus, the purpose of this study was to investigate the biomechanical analysis of the elbow in relation to throwing speed and pitching type. Method: Four overhead type high-school baseball players were recruited for this study. The participants were asked to throw balls with different types of pitch and speed. While the throwing speeds were measured, each pitching moment of the elbow was recorded. Descriptive statistics, frequency analysis, mean comparison analysis, and Pearson's correlation analysis were performed in order to examine differences in peak varus and valgus moment during pitching motion in the elbow in all throwing speed and pitching types. Results: There was no significant difference in physical characteristics, throwing speed, and momentum variability among all players. The mean varus moments were 44.38±1.55 Nm, 48.83±1.66 Nm, and 48.94±0.95 Nm, and the moment gaps between varus and valgus were 7.36±3.25 Nm, 7.44±2.02 Nm, and 7.36±2.62 Nm in fastball, curveball, and slider ball, respectively. The varus moment was higher in the curved and slider balls than in the fastballs, and there was no significant differences between the varus moments regarding the pitching type. However, the increase in valgus moment and decrease in moment gap according to throwing speed was significantly increased in the slider ball (r=0.718 and -0.591, respectively). Conclusion: The possibility of elbow injury caused by the valgus moment or moment gapincreases more rapidly in slider balls as the speed increases. Based on our results, appropriate pitching guidelines should be suggested to prevent ulnarligament injuries, especially in adolescent baseball players.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.591-604
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• 2017

The purpose of this study was to develop and evaluate the program for convericient reconfiguration in an attempt to change maladjustmental way of thinking among female junior tennis players. For verification of the program, a qualitative analysis and quantitative analysis were carried out. Through the REBT program for convericient reconfiguration, maladjustmental way of thinking among junior tennis players was drawed and interviews with them were subsequently performed. As a result, REBT counseling technique was applied to understand personal psychological problems and to transform maladjustmental and unreasonable way of thinking into rational belief, confirming positivity toward their situation. After all, their athletic performance as well as holistic development was found to be improved. In quantitative analysis, maladaptive thinking scale sports psychology questionnaire and survey for Korean sports performance strategy were both increased post treatment, suggesting that their psychological status became positive as a result of application of psychological prevention. The results of this study showed that athletic performance would be enhanced and growth and development in personality and self-realization would be expected if various psychological problems in adolescent players were progressed in detailed.

• Journal of Digital Convergence
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• v.17 no.5
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• pp.391-398
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• 2019

This study aimed to investigate the factors that influence the attitude toward doping and to provide useful information for developing a doping prevention program suitable for Korean athletic players. One hundred and seventy-two players who enrolled in Korea Association of Athletics Federations were participated in this study and they filled in the questionnaire about demographic factors, information on doping, perfectionism, and perceived motivational climate. Collected data were analyzed by using stepwise multiple linear regression for exploring the main factor that affect the attitude toward doping depending on field and track events. All adult players have more permissive attitude toward doping than adolescents. In track event, while players who are sensitive to coach's criticism have more permissive attitude toward doping, players who focused on personal standards have more repressive attitude toward it. These results would be useful to develop anti-doping strategy for Korean field and track players.

• Child Health Nursing Research
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• v.7 no.3
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• pp.383-396
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• 2001

This study was designed to investigate the effects of the progressive muscle relaxation on behavioral states and emotional reactions of adolescent athletes. The participants were 167 adolescent male soccer players aged between 12 and 18 who were junior or high school students in Seoul. Ninety-three of them were assigned to the experimental group, while seventy-four to the control group. The experimental group was treated by 10 sessions (20 min./session) of Jacobson's progressive muscle relaxation for two weeks, while the control group was not treated. The self and observer reported behavioral states, general stress by visual analogue scale, physical symptoms of stress, athletic stress, state anxiety, depression, self-esteem were measured before and after two weeks of the progressive muscle relaxation. The results were as follows ; 1. The self and observer reported behavioral states were significantly decreased in the experimental group compared with the control group. 2. The general stress and the gastrointestinal symptoms of stress were significantly decreased in the experimental group compared with the control group. No significant difference on athletic stress was found between the two groups. The depression and the state anxiety were significantly decreased in the experimental group compared with the control group. The self-esteem was significantly increased in the experimental group compared with the control group. 3. The influential factors on behavioral state of adolescent male athlete were depression and state anxiety. The accelerating factor on behavioral state change after the progressive muscle relaxation was state anxiety. These results are suggested that the progressive muscle relaxation could be effective in stabilizing behavioral state, decreasing general stress, gastrointestinal symptoms of stress, depression, state anxiety, in increasing self-esteem of adolescent male athletes. And the behavioral state change after the progressive muscle relaxation was influenced by state anxiety.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.7 no.2
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• pp.89-97
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• 2014

Purpose: To evaluate the ultrasonographic findings of the elbows on group screening of middle school baseball players. Materials and Methods: Ninety-three players (age: 12-15, mean 13.5 years) of four middle school baseball team were evaluated with bilateral elbow ultrasonographies in the field regardless of elbow pain. Medial and anterolateral ultrasound examination of the both elbow were performed in the field to detect any abnormalities including medial epicondylar separation or fragmentation and capitellar osteochondritis dissecans respectively. We analyzed the relationship among elbow pain, physical findings and sonographic abnormalities and the differences of sonographic abnormalities between pitchers and fielders. Results: Thirty-six of 93 (39%) players had sonographic abnormalities of elbow in dominant arm, 30 with medial epicondylar apophyseal separation or fragmentation, 2 with osteochondritis dissecans, 4 with both lesions. Twenty-nine of 37 (78%) players with elbow pain had sonographic abnormalities. On physical examination, players with medial epicondylar abnormalities had medial epicondylar tenderness (59%) and pain on valgus stress test (52%), and 5 of 6 (83%) players with osteochondritis dissecans showed flexion contracture more than $5^{\circ}$. The incidence of medial epicondylar abnormalities between pitchers and fielders was statistically not significant but osteochondritis dissecans was more prevalent in pitchers (p<0.05). Conclusion: Elbow sonography is a simple and useful screening tool in the field and also effective for early detection of medial epicondylar abnormalities or osteochondritis dissecans that could be the main causes of elbow pain in adolescent baseball players.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.1938-1945
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• 2014

This study intends to investigate physical trauma in the adolescent during exercise of teenage elite judo players in Seoul. The subjects were male 67, female 14, totally 81 in middle and high school student and the data collected june the first to 28th, 2013. A data were analyzed frequency analysis, chi-square test and t-test using SPSS 16.0 program. The questionaire was contained 6 categories, experience, region, types, time, causes, intervention and preventionof sports injury. The highest results of each categories of this study is that experience of injury is 77(95.1%), region is knee 35(70.0%), type is contusion 42(54.5%), time is summer 54(70.1%), cause is body crash 40(51.9%), and intervention is going hospital 46(59.7%). To prevent physical trauma, we should recognize physical trauma durind exercise as a health problem. And to prevent physical trauma, relatives should make prevention prorgram for adolescent sports players. It will improve their quality of life.

• Korean Journal of Child Studies
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• v.24 no.3
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• pp.109-134
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• 2003

Playing online games is popular among adolescents and may contribute to such social issues as game addiction and cyber-delinquency. The present study conducted an ethnographic analysis that addressed basic descriptive questions around the social significance of online games. The main findings were that peer pressure plays an important role; that is, adolescents play the games to fulfill their need to occupy higher levels of cyber-status among game players and build special relationships. They like to make money and buy what they want with money earned from game item deals. Game scenarios and mechanisms play an important role in game addiction. Adolescents sometimes exhibit social delinquency in cyberspace or the real world. Thus, adolescents' needs, game addiction and cyber-delinquency are intertwined.

• The Journal of Korean Association of Computer Education
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• v.8 no.2
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• pp.61-73
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• 2005

Mobile games have emerged as the most innovative entertainment technology, adding new revenue streams, taking advantage of the potential of wireless applications and service offerings. Mobile games, like any other types of computer game, offer a unique value for users in providing an exciting digital experience in virtual worlds. Players can become empowered through the development of new characters and strategies within games to achieve rewarding successes against the computers and other players. In this paper, we attempt to examine the motives of adolescents for playing mobile games. Based on data collected from survey, we have identified Escape, Arousal and Fantasy, Challenge and Competition, Diversion and Relaxation, Social interaction as the key motivators for playing mobile games. We also investigated the extent to which use and gratifications are predicted by demographic factors as well as by gaming experience. Statistical results confirm that most of the demographic factors played critical roles in determining the level of motivations for playing games. The results from this research might give mobile game industry some useful guidelines for developing mobile edu-game and market expansion strategy.

• Research in Community and Public Health Nursing
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• v.12 no.1
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• pp.125-141
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• 2001

The purpose of this study was to investigate the factors affecting hearing loss in adolescent's use of PCPs, and to give the basic data for adolescent's hearing conservation program development and prevention education against their hearing loss. This study was a descriptive research about three factors affecting hearing loss; the knowledge and attitude about noise, the perception of hearing loss and the hearing threshold. The subjects of this study were 383 students in two general high schools and two vocational high schools in Teagu. They have been using PCPs but with no current or past ear disease. This study was carried out from Sep. 1. 2000 to Oct. 24, 2000. The instrument used for the knowledge and attitude about noise was a questionnaire developed by Rhee. Kyung Yong and Yi. Kwan Hyung(1996). The instrument used for the perception of hearing loss was a Smith Hearing Screening Questionnaire. A Belton Model 112 Audiometer. air-conduction hearing test instrument. was used for the hearing threshold. Data was analysed by a SPSS/Win 10.0 program with frequency. percentage, t-test. ANOVA and pearson correlation. The results of this study were as follows; 1. The average of concern about hearing scored the highest $3.66{\pm}0.70$. The average of perceived susceptibility scored $2.64{\pm}0.85$ and the average of knowledge about noise scored $2.13{\pm}0.56$. The average of total knowledge and attitude about noise scored $2.82{\pm}0.46$. The average of discomfort of hearing loss($2.51{\pm}0.81$) scored higher than that fear of hearing loss($1.35{\pm}0.53$). The average of total perception of hearing loss scored $1.93{\pm}0.59$. The hearing threshold of the subjects scored the highest at 500Hz(Lt. $23.21{\pm}6.62$, Rt. $23.39{\pm}7.02$) and scored higher in order of 1000Hz, 2000Hz, 4000Hz and 8000Hz. 2. The knowledge and attitude about noise and the perception of hearing loss were both affected only by one important characteristic, which was general and vocational high schools. The knowledge and attitude about noise raked (t=5.258, p=0.000), and perception of hearing loss raked(t=2.241. p=0.026). However. several other important characteristics also impacted significantly on the knowledge and attitudes about noise. They included grade (t = 1. 987. p=0.048), father's education(F=2.745. p=0.043), marks(F=3.157, p=0.044), drinking(t=2.307, p=0.022) and smoking(t=2.587, p=0.010). The left hearing threshold differed significantly by sex at 1000Hz(t=5.175, p<0.001) and 8000Hz (t=3.334, p<0.01). According to general and vocational high schools (p<0.001), at 500Hz (t=-5.056), 1000Hz (t=-5.253), 2000Hz (t=-4.905), 4000Hz (t=-4.704) and 8000Hz (t=-5.204) significant differences were also shown. Marks were significant at 1000Hz (F=3.824, p<0.05) and drinking was found to be significant at 500Hz(t=2.203, p<0.05). The right hearing threshold differed significantly by sex at l000Hz(t=5.557. p<0.001). 4000Hz(t=2.234. p<0.05) and 8000Hz (t=2.730. p<0.01). According to general and vocational high schools(p<0.001) at 500Hz (t=-4.730), 1000Hz(t=-6.271). 2000Hz (t=-4.573). 4000Hz(t=-3.554) and 8000Hz (t=-3.405) significant differences were also shown. Grades impacted at 500Hz(t=2.201. p<0.05) and 4000Hz(t=2.511. p<0.05), while marks were significant at l000Hz(F=4.1l5. p<0.05) and drinking was significant at 500Hz(t=2.333. p<0.05). 3. The left hearing threshold in accordance with use of PCPs differed significantly at 2000Hz(F=2.996. p=0.03l) according to volume level and at 8000Hz(F=2.197. p=0.022) according to duration${\times}$hours per day. The right hearing threshold differed significantly at l000Hz(F=3.075. p=0.028) according to volume level and at 8000Hz(F=2.925. p=0.034) according to duration. 4. The knowledge and attitudes about noise showed a light positive correlation with the perception of hearing loss. A positive correlation was shown. as stated previously in all Hz, between the left hearing threshold and the right hearing threshold, especially the highest correlation at 2000Hz(r=0.761. p=0.000). This study has shown that the factors related to adolescent's use of PCPs are important as they impact significantly an adolescent's hearing. These results then indicate that in future, when designing a hearing conservation program and prevention education this data should be considered.