PURPOSE This study analyzed the difference in lower extremity joint angle and shock absorption patterns at the point of maximum ground reaction force during single-leg drop landing with or without anterior cruciate ligament reconstruction (ACLR). METHODS Forty adult males were recruited for this study, with 19 in the ACLR group (age: 20.52±1.43years, height: 179.26±5.18cm, weight: 74.91±6.29kg) and 21 in the control group (age: 21.42±1.61years, height: 174.97±6.83cm, weight: 69.27±7.56kg). Participants performed single-leg landings on a 30cm tall box. An independent sample t-test was used to analyze the difference in kinetics variables at the point of maximum ground reaction force upon landing, with significance set at p=0.05. RESULTS The lower limb joint angle showed significant differences in hip flexion, hip abduction, knee flexion, and knee valgus (p<0.05) between groups. There was no significant difference between the groups in terms of the results of kinetics variables during single-leg landing (maximum ground reaction force, lower extremity stiffness, and shock absorption time). CONCLUSIONS The ACLR group showed a clear difference in kinematics compared to the control group, but no significant difference in kinetic results was found. The two groups compensated for the same impact with different movements, though movements in the ACLR group may increase the risk of ACL re-injury. Those with ACLR should strive to reduce the risk of re-injury by training to use correct movements.
PURPOSE This study aimed to present the measures necessary to perform well in tennis clubs by examining the adaptation process of the MZ generation participating in tennis clubs. METHODS A qualitative case study was performed and data was collected through in-depth interviews, direct observations, and literature surveys. The data were analyzed by applying pattern matching among the analysis methods proposed by Yin (2014), and the reliability and validity of the study were demonstrated by consultations between colleagues, reviewing members, and comparing and analyzing previous studies. The study participants were seven MZ generation tennis club participants selected through snowball sampling (one of the non-probability samples). RESULTS Achieving a level of skill that allows for compatibility and the effort required for it, the acceptance of differences in club culture and between generations, having the etiquette necessary for Generation MZ, and falling for the charm of tennis itself were identified as factors for successful participation in tennis clubs. CONCLUSIONS This study is expected to help the MZ generation, who have recently been interested in tennis, continue their participation, as well as lay a small foundation for the expansion of the base of the sport by detailing the measures necessary to successfully participate in tennis clubs.
PURPOSE This study aimed to explore ways to utilize augmented reality (AR) in school sports and leisure by examining the case of an elementary school sports club using augmented reality-based e-sports. METHODS A self-study approach and Eisner's(1995) educational criticism were utilized. Data including photos, videos, literature, and memory boxes related to the elementary school AR sports club were collected weekly during the school semesters from March 2023 to January 2024, spanning a total of 30 weeks. The data were analyzed following the stages of analysis by Elo & Kyngäs(2007). RESULTS Augmented reality can act as a personalized exercise coach by visualizing physical activity information. Through posture and movement analysis, education on physical strength and expression can be provided that is linked to home; it can also expand the range of sports experiences and create a new sports culture. In order to effectively utilize AR, edtech field experts must be trained, and content must be developed through cooperation between companies and schools. The educational effectiveness of the content must be verified and the management system must be inspected, and public facilities utilizing edtech must be expanded. CONCLUSIONS AR has endless development potential in school sports and leisure, but these will require active interest and support from educational authorities.
PURPOSE This study aimed to verify the differences in anticipated regret and gambling discontinuance intent based on the fear appeal type and source similarity in different types of horse-racing gamblers. METHODS Using convenience sampling, 172 responses were collected from horse-racing participants who bought horseracing tickets within the last 6 months. After eliminating 30 insincere responses, descriptive, correlation, reliability, and two-way multivariate covariance analyses were conducted using SPSS Ver. 26.0. RESULTS Anticipated regret and discontinuance intent were higher under fear appeal using social compared with financial risk. Compared to recreational gamblers, problem gamblers had higher anticipated regret and discontinuance intent under fear appeal using social compared with financial risk. There were no differential impacts of source similarity on anticipated regret and discontinuance intent in both types of gambler. CONCLUSIONS Practitioners in charge of conducting messaging campaign to prevent addiction to horse-racing gambling may cause problem gamblers to expect regret and quit gambling by delivering preventive messages with relatively unfamiliar risks such as social risks, rather than familiar risks such as financial ones.
PURPOSE This study aimed to explore the structural relationships between technology-related factors and the intention to use baseball data, drawing upon the Unified Theory of Acceptance and Use of Technology (UTAUT) and technology readiness (TR). METHODS Survey data from 203 Korean professional baseball players were used in frequency, reliability, correlation, and confirmatory factor analyses as well as structural equation modeling. RESULTS Positive TR positively influenced performance expectancy, effort expectancy, social influence, and conditions facilitating baseball data use. Negative TR did not significantly impact performance expectancy, effort expectancy, social influence, and conditions facilitating baseball data use. Performance expectancy, effort expectancy, and facilitating conditions were found to positively influence data use intention, while social influence did not significantly impact data use intention. CONCLUSIONS The findings suggest that increasing performance expectancy, effort expectancy, and facilitating condition factors could be key to enhancing the intention to utilize baseball data.
PURPOSE This study comprehensively examined the aerodynamic and flight characteristics of modern soccer balls, focusing on their design evolution and performance attributes. METHODS The aerodynamic characteristics of five types of World Cup balls (2006 Germany World Cup, 2010 South Africa World Cup, 2014 Brazil World Cup, 2018 Russia World Cup, 2022 Qatar World Cup) and five types of Euro tournament balls (EURO2008, EURO2012, EURO2016, EURO2020, EURO2024) were examined, along with their respective design changes. RESULTS Through detailed analysis, significant variations in aerodynamic properties among soccer balls used in various tournaments were identified. Recent advancements have resulted in faster transitions towards critical Reynolds numbers, indicating improved stability in flight trajectories. This enhancement was attributed to the augmentation of surface roughness, which plays a crucial role in enhancing aerodynamic stability and overall performance. 2D simulations simulating powerful goalkeeper kicks revealed distinct differences in flight distances among different soccer balls; the Jabulani ball used in the 2010 World Cup exhibited the longest flight distance, while that of the 2024 Euro ball was the shortest. CONCLUSIONS Variations in surface texture significantly impact aerodynamic properties, affecting flight distance, arrival time, and height. This study underscores the significant design enhancements in modern soccer balls that optimize aerodynamic stability and performance, with modifications aimed at improving flight characteristics and enriching player experience.
PURPOSE By analyzing trends in Taekwondo demonstrations, specifically in breaking and performances, to date, this study aims to offer timely insights and set the groundwork for future research. METHODS We used Korean abstracts from a total of 425 papers containing the keyword “Taekwondo demonstrations” spanning 20 years from April 2004 to April 2023. We employed Python 3.5.2 to conduct dynamic topic modeling (Latent Dirichlet Analysis, LDA) and to examine the correlation between the topic distribution by section and the publication year. RESULTS The main findings from the LDA are as follows. Topic 1 (10%): “The development of demonstrations: performance in culture and art, ” Topic 2 (11%): “The development of formalized rules and judgments in a demonstration event,” Topic 3 (08%): “A study on the educational courses and professionalism of Taekwondo coaches,” Topic 4 (11%): “Technical movements and kinematic characteristics,” Topic 5 (09%): “A study on marketing perspectives of demonstration performances,” and Topic 7 (33%): “Global exchange: the development and rise of internationalization.” In the correlation analysis between the topic share by section and the publication year, Topics 1 to 5 exhibited no statistically significant correlation. However, Topic 6, “A study on the attainment of events, training, and the psychological factors influencing athletes” and Topic 7, “Global exchange: the development and rise of internationalization,” also displayed a very statistically significant but negative correlation. CONCLUSIONS Future research should focus on studies on the psychological management of athletes during the performance of specific techniques and training methods. Further research considering the global characteristics of Taekwondo may be required.
PURPOSE This study sought to investigate the effects of passive warm-up on flexibility, exercise performance, and lactate oxidation rate in track and field athletes. METHODS A total of eight male athletes with more than three years of athlete experience were recruited as participants, and passive warm-up (PW) and active warm-up (AW) treatments were conducted in a single-group crossover study design. The participants performed thermal stimulation at 40°C for 20 minutes as a PW and performed a 60-70% HRmax cycle as an AW. Flexibility and exercise performance were measured after each treatment. Anaerobic power was measured using the Wingate test, and lactic acid concentration was measured. RESULTS Body temperature significantly increased in both PW and AW, and no significant difference was observed in exercise performance between treatments. Flexibility and lactic acid oxidation rate were significantly higher in PW than in AW. CONCLUSIONS In track and field sprinters, PW did not exhibit any significant difference in anaerobic power and exercise performance compared to AW even though no physical exercise was performed, and PW was effective in body temperature, lactic acid oxidation rate, and flexibility. PW suggests the possibility of replacing AW.
PURPOSE This study sought to analyze the velocity and asymmetry between bilateral lower extremity mechanics according to the load during walking. METHODS A total of 14 adults with right leg dominance participated in this study (Male=7, Female=7). We respectively applied 30% of body weight load carriage on the subjects. Gait characteristics were analyzed with 3-dimensional cinematography and ground reaction force (GRF) system consisted of a center of gravity (COG) velocity, center of pressure (COP) area, leg stiffness, and GRF components. RESULTS Change in velocity of the maximum-minimum COG showed statistically significant in the main effect of load. The 1st anterior-posterior GRF (braking force) and vertical GRF were statistically significant in the main effects of load and bilateral lower limbs. The 2nd anterior-posterior GRF (propulsive force) was statistically significant in the main effect of load. COP area and leg stiffness exhibited statistically significant differences in the main effects of load and bilateral lower limbs. Interaction was observed in the vertical GRF, COP area. Furthermore , one-way variance analysis revealed load main effect had a greater influence on the increase in the magnitude of the vertical GRF and COP area than the asymmetry of bilateral lower limbs. CONCLUSIONS This study revealed the differences in asymmetry between the dominant and non-dominant lower limbs according to the load during walking. These findings may explain the differences shock attenuation and stress mechanisms between the bilateral lower limbs.
PURPOSE This study seeks to contribute to the enhancement of the performance of domestic wheelchair racers by producing 3D-printed customized gloves and verifying their application effect. METHODS A total of three male wheelchair racers who belong to the T54 and have won gold medals in the National Para Games within the last three years were selected as subjects. Each subject performed three session s of muscle activity and maximum speed measurements before and after applying a 3D-printed glove during the stroke and recovery phases of wheelchair racing, focusing on the pectoralis major (PM), triceps brachii (TB), and erector spinae (ES) muscles. To standardize the muscle activity measurement data, the relative muscle activity level (%) for each section was calculated by maximum voluntary isometric contraction (MVIC) for each subject. All maximum speeds of each round of driving were calculated by the average record for comparative analysis. In addition, to verify the effectiveness of applying the 3D-printed glove, the Wilcoxon signed rank test, which is a non-parametric test method, was performed on all measured values using SPSS 24.0. RESULTS This study derived the following results. First, a statistically significant difference was observed in the muscle activity of each major muscle before and after using the 3D-printed glove. In common, an increase in muscle activity of the PM, TB, and ES was confirmed in the stroke section, and an increase in muscle activity of the TB was confirmed in the recovery section. Second, a statistically significant difference was documented in the maximum speed before and after using the 3D-printed glove. When using 3D-printed gloves, the maximum speed increased by 4.57, 3.63, and 1.06km/h for Payer A, and by 5.9, 6.04, and 7.86km/ h for Player B. In the case of Player C, the speed increased by 6.73, 2.27, and 0.83km/h, and all three players improved their maximum speed through the 3D-printed gloves. CONCLUSIONS Our study suggests that the application of 3D-printed customized gloves can have a positive impact on the performance of wheelchair racers. If the application of 3D-printed customized equipment is extended to athletes in a wider range of sports in the future, this could significantly contribute to the improvement of performance in domestic disability sport.
