• Journal of the Korean Society of Physical Medicine
• /
• v.18 no.1
• /
• pp.37-50
• /
• 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 Sport and Applied Science
• /
• v.7 no.2
• /
• pp.1-12
• /
• 2023

Purpose: The purpose of this study was to investigate the possibility of modified swing to prevent shoulder injury by analyzing differences in the muscle activation patterns of upper limb by the swing method in wheelchair badminton players. Research design, data, and methodology: 10 wheelchair badminton players participated in the experiment as subjects and performed 10 high clears and 10 smashes in both traditional and modified swing methods toward a shuttlecock hung at the height of racket impact point. For each trial, activation patterns of biceps brachii, triceps brachii, anterior deltoid, and posterior deltoid were measured from the upper limb participating in the swing from which the duration, peak, and root mean square (RMS) of electromyography (EMG) activities from swing initiation to shuttle impact were calculated. The maximum swing velocity of the smash and the distance of the high clear were also measured with both methods to compare differences in the swing velocity and shuttle hit distance. Results: Differences in the EMG peak and RMS of the anterior deltoid by swing methods were shown to differ by the skill type, being higher in the traditional swing method than the modified during only the high clear. The EMG peak and RMS, and the duration of the posterior deltoid were higher and longer with the traditional swing method than the modified during both the smash and high clear. The intensities of the biceps brachii and triceps brachii activities measured during the smash and high clear were higher in the traditional swing method than the modified, and the biceps brachii and triceps activity durations during the high clear were shorter in the modified swing method than the traditional. The maximum swing velocity of the smash was faster with the traditional swing method than the modified, while the distance of the high clear did not differ significantly. Conclusions: These results suggest that the modified swing can be an effective performance method for preventing shoulder injuries without undue loss of impact power in wheelchair badminton players by reducing excessive loads imposed on the shoulder and allowing the optimal use of the elbow extension.

• The Research Journal of the Costume Culture
• /
• v.32 no.1
• /
• pp.58-69
• /
• 2024

The purpose of this study was to develop the Functional golf inner-wear by preventing the injuries and enhancing the performance of the Golf swing by checking the influence of the wearing of the functional golf inner-wear considering golf characteristics on the Swing trajectory and Shot distance. Functional inner-wear effective for golf swing was manufactured using the sports taping method. Changes in driver and iron swing before and after wearing the functional golf inner-wear manufactured in this way were measured using trackman equipment. Measurement variables were limited to Club Speed, Attack Angle, Club Path, Ball Speed, Smash Factor, and Priority. Before and after wearing functional golf inner-wear, there were statistically significant differences in driver club speed, iron club speed, driver etch angle, iron club pass, driver ball speed, driver smash factor, iron smash factor, driver carry, iron carry, and right shoulder joint proprioceptive sensory ability. As a result, functional golf inner-wear is effective for ball speed, impact, and carry by increasing club speed and efficient swing. Future research will focus on the development of functional golf that can improve the swing ability in a short game that plays an important role in the golf game through various sports taping grafting technique, textile, special material, film, Research on functional golf inner-wear.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.2
• /
• pp.519-524
• /
• 2023

The purpose of this study is to construct basic data for efficient technical training by investigating the difference in muscle activity during badminton technical movements involving jump motions similar to game situations. Seven male badminton players were randomly assigned to perform smash, drop, and clear techniques, and electromyograms were measured during the implementation of three technical movements. Measured EMG was calculated by RMS and one-way ANOVA was performed. The muscle activity of the smashing motion did not show any significant difference according to the site. In drop motion, activity of PM in the upper extremity muscles was lower than that of BC and ECR, and FCR activity was lower than that of EC. The activity of ECR was higher than that of PM and FCR. The activity of ES in trunk muscles was lower than that of RF and GM. RF activity of lower extremity muscles was higher than that of ES and BF. In clear motion, the activity of TC in upper extremity muscle was higher than FCR. The activity of ES in trunk muscles was lower than that of BF. RF activity of lower extremity muscles was higher than that of BF, and BF activity was lower than that of RF and GM. The activity of GM was higher than that of BF. As for muscle activity according to badminton skills, smash and drop motions were higher than clear motions in FCR, and clear motions were higher than smash and drop motions in RA. In conclusion, it is considered that muscle activity during the badminton game is different according to the characteristics of each skill, and FCR can affect the smash and drop, and RA can affect the clear motion.

• Journal of Digital Convergence
• /
• v.12 no.9
• /
• pp.465-474
• /
• 2014

This research aimed to enhance the effects of training through the use of infrared cameras located at anterior and posterior positions. The results were as follows. In the case of the smash, the impact time needed to be adjusted to raise their impact point. The smash of S1, on the other hand, was a step smash, which showed the fastest racquet head speed and the greatest transmission of power upon impact. As the max racquet speed upon impact and during speed was similar, S1 showed the best impact time. All athletes except S6 were shown to use their right foot as their 1 step that was located in front upon landing, using a hop step as their first step. For the best swing upon stroke, it is important to make the best conditions possible for the use of elbow joints and wrist joints. The rotating radius of the racquet should be big and the shuttlecock should be fast. Balance is important in footwork, or the coordinated movement of the feet. Without a correct step it is difficult to execute an efficient stroke. In an actual game, steps need to be executed in 2 to 4 steps, and programs focusing on steps according to situation, agility and reaction need to be executed.

• Communications of the Korean Mathematical Society
• /
• v.11 no.1
• /
• pp.225-233
• /
• 1996

It is shown that for any space A, the cofibration X \to X \Join \sumA \to \sumA \wedge X$ decomposable when X is a co-T-space. It is also obtain necessary and sufficient conditions for the cofibration $X \to X \Join A \to A \wedge X$ is trivial, in the sense of cofibre homotopy type.

• Korean Journal of Applied Biomechanics
• /
• v.25 no.1
• /
• pp.11-19
• /
• 2015

Objective : The purpose of this study was to analyze the correlation between physical factors (X-factor, X-factor stretch) and club factors (club speed, ball speed, club path, smash factor, vertical launch angle, spin rate, flight time, total length) during impact and it affect on the total distance of the ball during a golf driver swing. Background : There were not enough studies that analyzed the correlation between physical factors(X-factor, X-factor stretch) and club factors(club speed, ball speed, club path, smash factor, launch angle, spin rate, flight time, total length) during a purpose swing to increase total distance. Method : For this study, 9 right handed professional male golfers (KPGA) were chosen. The test subject group used their own drivers and each took a total of 10 swings. These swings consisted of 5 purpose swings to increase total distance and 5 normal swings. Results : The purpose swing to increase total distance showed larger physical factors(X-factor, X-factor stretch) compared to a normal swing however the results were not statistically significant. Total distance increased during a purpose swing as a result of ball and club speed. Conclusion : The results showed that club factors, ball speed and club speed contributed the most in affecting the total distance of the ball during a purpose swing.

• Applied Chemistry for Engineering
• /
• v.22 no.1
• /
• pp.26-30
• /
• 2011

In order to improve the energy conversion efficiency of dye-sensitized solar cell (DSSC), the photoelectrode was manufactured by using $TiO_2$ and $WO_3$ on combination effects of two conduction bands. The smash procedure of $TiO_2$ and $WO_3$ was carried out by using a paint shaker to enlarge the contact area of semiconductor with dye and electrolyte. The energy conversion efficiency of prepared DSSC was improved about two times from current-voltage curve based on effects of $WO_3$ and smash. The mechanism was suggested that the conduction band of $WO_3$ worked for prohibiting the trapping effects of electrons in conduction band of $TiO_2$. This result is attributed to the prevention of electron recombination between electron in conduction band of $TiO_2$ with dye and electrolyte. Impedance results indicate the improved electron transport at interface of $TiO_2$/dye/electrolyte.

• Journal of the Korean Applied Science and Technology
• /
• v.38 no.1
• /
• pp.1-8
• /
• 2021

The purpose of this study was to analyze relationship between biomechancal factors and diver's distance during golf driver swing. Fifteen professional golfers were participated in as subject. Eight motion capture cameras(250 Hz), 2 force plates(1000 Hz), and Trackman were used to collect kinematic and kinetic datas. It was performed Pearson's correlation analysis using SPSS 24.0. The level of significance was at .05. Ball speed, club head speed, X-Factor, and ground reaction force were correlated on driving distance, However, smash factor and knee moment were not correlated on driving distnace. Ball speed, club head speed, X-Factor, and ground reaction force were effected to driving distance, but smash factor and knee moment were not effected to driving distance.

• The Plant Pathology Journal
• /
• v.36 no.5
• /
• pp.491-496
• /
• 2020

An understanding of the contribution of secondary metabolites (SMs) to the antagonistic and biocontrol activities of bacterial biocontrol agents serves to improve biocontrol potential of the strain. In this study, to evaluate the contribution of each SM produced by Pseudomonas fluorescens NBC275 (Pf275) to its antifungal and biocontrol activity, we combined in silico analysis of the genome with our previous study of transposon (Tn) mutants. Thirteen Tn mutants, which belonged to 6 biosynthetic gene clusters (BGCs) of a total 14 BGCs predicted by the antiSMASH tool were identified by the reduction of antifungal activity. The biocontrol performance of Pf275 was significantly dependent on 2,4-diacetylphloroglucinol and pyoverdine. The clusters that encode for arylpolyene and an unidentified small linear lipopeptide influenced antifungal and biocontrol activities. To our knowledge, our study identified the contribution of SMs, such as a small linear lipopeptide and arylpolyene, to biocontrol efficacy for the first time.