• Korean Journal of Applied Biomechanics
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• v.13 no.2
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• pp.65-74
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• 2003

The purpose of this study was to analyze kinematic variables in the badminton smash motion through 3-dimensional image analysis. The kinematic variables were velocity of joints in upper limbs, the angle of wrist in the impact, and the angular velocity of the top of racket head. The smash motions of four male badminton players in H University and four male students at department of the physical education in K University who were not majoring in badminton were analyzed kinematically and the attained conclusions were as follow. 1. The velocity of segments in upper limbs of the unskilled group was faster than that of the skilled group. The movement pattern was fast back swing-slow impact moment-fast fellow through in the unskilled group, but slow back swing-fast impact moment-slow follow through in the sullied group. 2. As the BS phases, the velocity of segment in right shoulder was different significantly between groups. Right elbow and right wrist segments, velocity of racket head was different significantly between groups(p<.05) by IP phases. As the FT phases, there was no significant difference. 3. The angle of right wrist at the impact, the angle of palm flexion and the angle of palm flexion in aspect were shown that the skilled group was higher than unskilled group. There was no significant difference. 4. The velocity of racket head was shown that the unskilled group has fast velocity, but the angle velocity was shown the unskilled group has slow. 5. The angle velocity of racket head in aspect were no significant difference between groups, but maximal angle velocity was different significantly between groups(p<.05).

• Korean Journal of Applied Biomechanics
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• v.22 no.4
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• pp.387-394
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• 2012

The purpose of this study was to compare and analyze the finger pressure and kinematic variables in the forehand hairpin net shot between skilled elite players and less skilled recreational players. Eight elite players(age: $18.1{\pm}0.8yrs$, height: $176.8{\pm}1.5cm$, weight: $640.9{\pm}48.6N$) with minimum of 6 years of experience and eight recreational players(age: $27.9{\pm}1.6yrs$, height: $177.1{\pm}6.1cm$, weight: $820.5{\pm}62.8N$) with less than one year experience were recruited in this study. For each trial being analyzed, four critical instants were identified from the video recordings: Right heel contact1 (E1), Right toe-off (E2), Right heel contact2 (E3), and Shuttlecock Impact (E4). Each hairpin net shot was broken into consecutive phases: E1~E2 (Right Landing Phase: RLP), E2~E3 (Sliding Step Phase: SSP), and E3~E4 (Impact Phase: IP). Temporal parameters, shuttlecock speed, linear and angular kinematics of body segments, and finger pressures were computed for this study. The results showed that The finger pressure of the ring finger and the middle finger for the skilled group during an impact had significantly greater than those of unskilled group. It is possible that all fingers were not used in the same manner when the racket was gripped in forehand hairpin. The result also suggested that the ring finger and the middle finger pushed the racket from top to bottom while having the mid-phalanx and proximal phalanx of index finger as an axis.

• Korean Journal of Applied Biomechanics
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• v.23 no.3
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• pp.201-208
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• 2013

The aim of this study was to investigate badminton smash and drop motion depends on player's level. To perform this study, ten male badminton players were participated: five skilled players (SG, age: $21.6{\pm}1.1$ yrs, height: $181.4{\pm}6.8$ cm, body mass: $72.4{\pm}5.7$ kg, career: $11.2{\pm}1.1$ yrs) and five less-skilled players (LSG, age: $21.2{\pm}1.1$ yrs, height: $180.2{\pm}5.6$ cm, body mass: $73.6{\pm}6.7$ kg, career: $10.6{\pm}0.9$ yrs). Three-dimensional motion analysis with 7 infrared cameras was performed with a sampling frequency as 200 Hz. Player's swing motion was divided into four events: starting motion (E1), backswing (E2), impact (E3), following (E4). For all upper joints, LSG showed greater angle differences between drop and smash motions than that of SG at E3 (p<.05). For all upper joints, greater angular velocities were found in SG than that of LSG. For both groups, significantly smaller angular velocities were found in drop motion than that of smash motion (p<.05). The greater sequential angular velocities (proximal to distal) were found in SG than LSG during smash motion. Based on our findings, performing the same motion between drop and smash would be related to enhance performance at badminton competition. It is expected that these results will be useful in developing a training program for enhancing performance of badminton athletes.

• Journal of the Korean Arthroscopy Society
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• v.13 no.3
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• pp.259-263
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• 2009

The plica is a remnant of the synovial folds during fetal development. The plica is classified suprapatellar, medial patellar, infrapatellar, and lateral patellar plica according to the anatomic site. The one most likely cause of clinical problem is medial patellar plica. There are many reports of problems caused by medial patellar plica syndrome. But there has been no documented case report of Outerbridge classification Grade III-IV, above $2{\times}1.5\;cm$ sized huge cartilage defect of both medial femoral condyle, due to medial patellar plica. So we report this unusual case with a review of relevant literatures.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.1
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• pp.37-50
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• 2023

PURPOSE: This study examined the effects of various interventions for improving the hip joint range of motion on elite badminton players, including body balance ability, jumping power, smash speed, and joint range of motion. METHODS: The study was conducted on elite badminton players belonging to the S badminton team in Yongin, Gyeonggi-do, and the M badminton team in Suwon, Gyeonggi-do. Twenty-one elite badminton players were selected; they were assigned randomly to Experimental Group 1 (n = 11) and Experimental Group 2 (n = 10). Before and after the intervention, the hip joint range of motion, modified star excursion balance test, Sargent jump, and smash speed were measured. In Experimental Group 1, hip joint manual mobilization was applied by a physical therapist, and hip self-exercise performed by the athletes was applied in Experimental Group 2. This intervention was applied once a day, three times a week, for four weeks. RESULTS: A significant increase in the hip joint range of motion (flexion and extension) and modified star excursion balance test (posteromedial direction) was observed in Experimental Group 1 (hip joint mobilization applied group) compared to Experimental Group 2 (hip joint self-exercise applied group) (p < .05). CONCLUSION: When elite level badminton players require improvement in hip flexion and extension range of motion and posteromedial body balance, hip joint mobilization is more effective than hip self-exercise application.

• Journal of Fashion Business
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• v.27 no.5
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• pp.93-107
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• 2023

This study aimed to design a knee brace with dry electrode EMS (Electrical Muscle Stimulation) for elite badminton players suffering from knee pain and assess its effectiveness in relieving pain and improving mobility. The assessment measured knee joint range of motion (ROM), Sargent jump height, and pain perception using a visual analog scale (VAS). Four experimental groups were established: stability, pain induction after 100 squats, muscle soreness induction with a regular knee brace, and muscle soreness induction with the EMS knee brace. The most suitable knee brace was selected from four samples to design the EMS knee brace. The conductive fabric was integrated into the inner surface of the knee brace to enhance EMS conductivity for the quadriceps muscles. Tensile strength tests showed that the dry electrode did not significantly affect the physical functionality of the knee brace.Regarding knee joint ROM and Sargent jump height, the EMS knee brace outperformed muscle soreness induction with a regular knee brace and wearing a standard knee brace. VAS measurements demonstrated that the EMS braces effectively alleviated pain perception in most cases. The results indicate the potential for developing EMS braces to alleviate pain and prevent injuries for athletes across various sports.

• The Journal of the Korea Contents Association
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• v.17 no.7
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• pp.283-293
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• 2017

This study analyzed the actual conditions of use of public sports facilities and characteristics of the users of the facilities through surveys and measured the spatial imbalance of the public sports facilities currently supplied by using gravity potential model. This study also suggests evaluation criteria that may be considered for efficient location selection by examining the change of accessibility to the facilities that meet the needs of users in the future. As the results of the questionnaire survey, unlike current usage, the users hoped for badminton, weight training and swimming. And we could confirm the demand for the expansion of the multi - purpose indoor gym which can carry out such activities in the areas. As the result of the analysis on the difference in accessibility of the public sports facility, there were some large variations in the regions. It was found that a balanced supply of facilities was needed in terms of equity. In particular, when analyzing by considering the population estimates of 2025, It is analyzed that the accessibility will be reduced to about 60% compared to that of 2015. In addition, it is evaluated as the best alternative in terms of overall efficiency that the location of the facilities should be in Munsan area where population growth is expected in the future.

• Journal of the East Asian Society of Dietary Life
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• v.6 no.1
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• pp.33-39
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• 1996

The aim of this study is to estimate the prevalence of obesity and factors with it Ulsan secondary school girls. A cross-sectional study involving a sample of 485 students aged 12 to 15 years was obtained form secondary schools. Obesity was determined using body mass index(BMI=wt/Ht$^2$). The findings revealed that the average BMI was 19.3, and 4.5% of girls were either overweight and obese(BMI$\geq$25). Subjects were grouped into three categories based on the BMI, sibling obesity, self-consciousness of obesity, eating patterns such as eating snack after dinner and prejudice in food selection, and food frequency score were significantly associated nth BMI, while nutrition knowledge score was not associated with BMI. The fact that several social, environmental and health factors are associated with obesity means that a multisectorial intervention program must be considered in order to decrease the problem of overweight among secondary girls. Such program should include dietary intervention to modify food habits, nutrition education through mass media, introducing information on prevention and control obesity in school curriculum, and allocating sufficient time in the school schedule for exercise activities.

• Journal of Intelligence and Information Systems
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• v.28 no.3
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• pp.57-79
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• 2022

COVID-19, which started in December 2019, has had a great impact on our lives in general, including politics, economy, society, and culture, and activities in sports and arts have also been significantly reduced. In the case of sports, sports for all fields in which ordinary citizens participate were particularly affected, and cases of infection in places closely related to people's lives, such as gyms, table tennis, and badminton clubs, also amplified the social fear of the spread of COVID-19. Therefore, in this study, we analyzed news articles related to sports for all at the time when COVID-19 was first spread, and investigated what issues were emerging and being discussed in the sports for all field under the COVID-19 situation. Specifically, we collected news articles dealt with sports for all issues under the COVID-19 situation from Korea's leading portal news sites and identified key sports for all issues by performing topic modeling on these articles. Through the analysis, we found meaningful issues such as COVID-19 outbreak in sports facilities and support for sports activities. In addition, through wordcloud analysis of these major issues, we visually understood the issues and identified the changes in these issues over time.

• Journal of Korean Orthopaedic Sports Medicine
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• v.1 no.1
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• pp.31-36
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• 2002

Purpose : ACL (anterior cruciate ligament) reconstruction using achilles allograft was done for whom ACL injured person in recreational sports activity. The purpose of this study was to evaluate the clinical results and return to their sports activity in these patients. Materials and Methods : ACL injured 56 amateur athletes who had experienced sports 3 times a week more than 5 years, reconstructed with Achilles allograft, and it was analyzed subjective and objective parameter, Tegner scoring, Telos stress arthrometer, Lysholm Knee Scoring System and modified Feagin scoring system. The average age was 25 years old (range: 18$\~$49), the average follow up period was 15 months (range: 12$\~$19). Morbid sports were football (29 cases), basket ball (14 cases), badminton (5 cases), tennis (3 cases), squash (2 cases) and otherwise (3 cases). Result : The mean Lysholm Knee Scoring System was improved to 88.2 from 60. Telos arthrometer in anterior stress test revealed 2.3 mm improved from 7.1 mm. The modified Feagin scoring system showed 50 cases (89$\%$) with excellent and good results. We had obtained 12 cases (21$\%$) of Tegner score VI, 32 cases (57$\%$) of score V, 20 cases (35%$\%$ of score IV, 3 (5.3$\%$) cases of score III. Conclusions : Reconstruction of anterior cruciate ligaments can restore stability sufficient to allow sports activity in ACL injured patients, but it’s difficult to achieve 'normal' sports activity. So we will have to solve the reasons of this dissatisfaction at furthermore.