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.

Purpose: The purpose of this study is to provide directions and implications related to eco-friendly marketing and products of outdoor brand companies by empirically analyzing the influence of outdoor brand's eco-friendly activities on brand image and word of mouth. Research design, data, and methodology: In this study, a survey was conducted on those who have purchased outdoor brand products through the convenience sampling method, and a total of 470 effective samples were collected. Frequency analysis, reliability analysis, confirmatory factor analysis, and structural equation model analysis were conducted based on the collected data. Results: As a result of the analysis, first, it was found that eco-friendly marketing among the eco-friendly activities of outdoor brands did not have a positive effect on the brand image. Second, among the eco-friendly activities of outdoor brands, eco-friendly products were found to have a positive effect on the brand image. Third, it was found that the brand image had an effect on word of mouth intention. Conclusions: Academic and practical implications were discussed based on the research results that eco-friendly marketing of outdoor brands does not have a positive effect on brand image, eco-friendly products have a positive effect on brand image, and brand image affects word of mouth.

Purpose: This study was to investigate the effect of a 12-week plyometric training on body composition, physical fitness and bone mineral density in obese male adolescents. Method: Twenty adolescent boys who are obese were randomly assigned to a control group (CON, n=10) or plyometic exercise group (EXE, n=10). The EXE group was performed 3 times per week for 12 weeks. The body composition, physical fitness, and bone mineral density were measured before and after the 12 weeks intervention. Results: The results of this study were as follows: i) In EXE group, the fat mass was significantly decreased between pre and post, whereas the difference of the body weight, BMI, and LBM were not significant. ii) Among the physical fitness factors, grip strength, muscular endurance, and 2 0m shuttle running were significantly improved but flexibility did not show any significant difference. iii) The bone mineral density was significantly improved between pre and post in EXE group. Conclusion: These results suggested that plyometric training for 12 weeks may be effective in improving body composition, physical fitness, and bone mineral density in obese adolescents. Further implications were discussed.

Purpose: The purpose of this study is to examine the structural relationship among relationship marketing, relationship quality, and behavioral intention toward children sports centers. Research design, data, and methodology: To achieve this purpose, this study employed a convenience sampling method via a questionnaire dissemination. A total of 427 responses were collected from the parents of six children sports centers. Among those, 21 responses were excluded as they were not completed, leaving 406 valid data. For hypotheses test, the collected data was computed in SPSS 27.0 and AMOS 27.0, and analyzed with frequency analysis, correlation analysis, reliability analysis, confirmatory factor analysis, and structural equation modeling analysis. Results: First, relationship marketing had a positive influence on relationship quality. Second, relationship marketing had a positive influence on behavioral intention. Third, relationship quality had a positive influence on behavioral intention. Conclusions: Results showed that relationship marketing had a positive influence on relationship quality and behavioral intention. Moreover, relationship quality had a positive influence on behavioral intention. These findings indicate a positive function of relationship marketing in building psychological and behavioral outcomes in the context of children sport industry. Given this, implications of relationships among research variables were discussed.

Purpose: The purpose of this study was to investigate differences in the control process to satisfy spatial and temporal constraints imposed upon the anticipation timing response by analyzing the effect of spatio-temporal accuracy demands on eye movements, response accuracy, and the coupling of eye and hand movements. Research design, data, and methodology: 12 right-handed male subjects participated in the experiment and performed anticipation timing responses toward a stimulus moving at three velocities (0.53m/s, 0.66m/s, 0.88m/s) in two task constraint conditions (temporal constraint, spatial constraint). During the response, response accuracy and eye movement patterns were measured from which timing and radial errors, the latency of saccade, fixation duration of the point of gaze (POG), distance between the POG and stimulus, and spatio-temporal coupling of the POG and hand were calculated. Results: The timing and radial errors increased with increasing stimulus velocity, and the spatio-temporal constraints led to larger timing errors than the temporal constraints. The latency of saccade and the temporal coupling of eye and hand decreased with increasing stimulus velocity and were shorter and longer respectively in the spatio-temporal constraint condition than in the temporal constraint condition. The fixation duration of the POG also decreased with increasing stimulus velocity, but no difference was shown between task constraint conditions. The distance between the POG and stimulus increased with increasing stimulus velocity and was longer in the temporal constraint condition compared to the spatio-temporal constraint condition. The spatial coupling of eye and hand was larger with the velocity 0.88m/s than those in other velocity conditions. Conclusions: These results suggest that differences in eye movement patterns and spatio-temporal couplings of stimulus, eye and hand by task constraints are closely related with the accuracy of anticipation timing responses, and the spatial constraints imposed may decrease the temporal accuracy of response by increasing the complexity of perception-action coupling.

Purpose: This study examines the role of leaders of sport organizations from the perspectives of rank-and-file volunteers. Specifically, the study explores which factors are important in leading volunteers and how rank-and-filers interact with their leaders. Research design, data, and methodology: This study reviews a comprehensive literature on volunteer and leadership theories which are trait theory, behavior theory, and contingency theory. Given the comprehension of prior structure of knowledge on leadership, the study provides a structure of knowledge on volunteer and leadership in sport context and discusses managerial implications for leaders in sport organization. Results: With an exploration of sport leadership, this study proposes a volunteer classification model which presents four-volunteer types: professional volunteer, company volunteer, general volunteer, and school volunteer. Furthermore, this study discussed managerial implications for sport organization leaders. Conclusions: Paid employees may be prepared to accept a job and its requirements mainly due to economic benefits. Volunteers, however, do not pursue economic benefits through their activity. Different types of motivation between paid employees and volunteers bring to surface how a leader influences volunteer effectively. A conceptual volunteer clarification model could be examined in real world situations. Insights for future studies were discussed.