PURPOSE The purpose of this study was to provide information for improving the performance and skills of 500 m speed skaters by analyzing the kinematic and kinetic changes in their slide board movements over time. METHODS The subjects were 10 male short-distance skaters in their 20s to 30s who were registered as professional athletes with the Korea Sports Council. The changes in joint angle, joint moment, and joint power over time in the subjects’ slide board motion were measured and analyzed. RESULTS It was found that during phase 2 of the skater’s slide board movement, there was an increase in plantar flexion and a decrease in flexion of the lower extremity joint and extension of the knee and hip joint, with decrease in positive power of the knee joint. CONCLUSIONS The results of this study are expected to provide practical information to skating coaches and athletes by quantifying the biomechanical factors observed over time during slide board movements. In addition, this study is expected to contribute to the field of speed skating by presenting scientific training methods and proposing new analysis techniques to improve performance in the future.
PURPOSE The purpose of this study was to investigate the characteristics of field and on-ice performances of ice-hockey players and the relationship of performance with subjective joint pain and dysfunction. METHODS A total of 25 male college icehockey players were evaluated for 19 items of performance. Pain and dysfunctions in the lower extremities and lower back were confirmed through the Foot and Ankle Outcome Score, Knee Injury and Osteoarthritis Outcome Score, Hip Dysfunction and Osteoarthritis Outcome Score, and Osweatry Disability Index questionnaire. Players with similar performance characteristics were classified through a cluster analysis, and differences in performance and patient-reported outcomes between clusters were analyzed with a one-way analysis of variance. RESULTS The ice-hockey players were classified into “lower muscular strength and performance (cluster 1),” “lower cardiorespiratory endurance (cluster 2),” and “high muscular strength and performance (cluster 3).” Players in cluster 1 had more frequent ankle and knee joint dysfunctions and pain compared to those in cluster 3. Several performance test items affected the subjective joint score, and the related performance items were more in the proximal joint than in the distal joint. CONCLUSIONS Ice hockey players should perform training to supplement their individual lack of on-ice and field performance. Since performance may be limited because of joint dysfunction and pain, a joint-specific intervention strategy should be applied to improve physical and athletic performances.
PURPOSE This study aimed to identify the influence of certain factors on spectators' spectating behavior through the analysis of spectator-type Taekwondo spectators’ spectating behavior by applying the extended theory of planned behavior and embodied cognition theory and considering spectators’ desire to stay. METHODS A total of 305 surveys were used as the final sample. SPSS 24.0 and AMOS 26.0 were used for frequency , correlation, confirmatory factor, and structural equation model analyses. RESULTS First, attitudes, subjective norms, perceived behavioral control, and prior knowledge, which are predictors of the extended theory of planned behavior, had a statistically significant effect on the spectators’ desire to stay. Second, the spectators’ desire to stay had a statistically significant effect on the spectators’ content , environment, and behavior. Third , the spectators’ content and environment, which are sub-factors of the embodied cognition theory, had a statistically significant effect on the spectators’ behavior. CONCLUSIONS The study results suggest that attitudes, subjective norms, perceived behavior control, and prior knowledge, which are predictors of the extended theory of planned behavior, have a positive effect on the embodied cognition and spectator behavior of spectator-type Taekwondo spectators.
PURPOSE The purpose of this study was to examine the effect of visual color perception on autonomic nervous activity and exercise capacity in healthy male college students. METHODS The subjects who were healthy male college student (n=10) were participated in 4 visual colors using by randomized crossover; clear color group (CG), red color group (RG), blue color group (BG) and green color group (GG). All subjects wore goggles for five minutes prior to the exercise to adjust to color, and they did not take off goggles until recovery after exercise. Significant differences between groups were determined by two-way repeated measures ANOVA. RESULTS As a result of this study, the low frequency (LF) was significantly higher in RG than those in GG. But the high frequency (HF) was significant higher in BG compared to GG. Exercise capacity such as maximum strength, muscle endurance, reaction time, power, agility and aerobic performance did not differ significantly between all groups. CONCLUSIONS Therefore, our findings suggested that perception of the visual color might be change autonomic nervous activity, while don’t influence exercise capacity.
Purpose The purpose of this manuscript was to investigate the effect of high and low speed blood flow restriction versus non-blood flow restriction isokinetic exercise on isometric muscle strength, muscle fatigue, and muscle contraction displacement. Methods The subjects were consisted of ten males without non-specific muscular skeletal disease. They were classified into four training groups: ① high speed(300°/s) without blood flow restriction, ② high speed(300°/s) under blood flow restriction, ③ low speed(90°/s) without blood flow restriction, ④ low speed(90°/s) under blood flow restriction. Before and after the intervention, all of the subjects underwent measurements of isometric quadriceps strength, muscle fatigue, and muscle contraction displacement. Results In regard to isometric quadriceps strength before & after intervention, there was no significant difference between groups. For the lactic acid measurement before & after intervention, there was a signigicant difference between groups(p<.05). Also, there was a significant difference between groups(p<.05) in muscle contraction displacement in terms of Dm but there was no significant difference between groups in terms of Tc Conclusions Isokinetic exercise with blood flow restriction had effects on lactic acid and muscle contraction displacement.
This study was designed to investigate the effects of combined treatment of chiropractic and PNF exercise on musculoskeletal function in forward head posture patients. Thirty patients volunteered to participate in the study as subjects, and they were divided into one of three groups, i.e., chiropractic group (n=10), PNF exercise group (n=10), and combined treatment of chiropractic and PNF exercise group (C+P group; n=10). Subjects in three groups went through each program for 25 min/session, three times/wk for eight weeks. Cervical alignment, cervical muscular strength and endurance, and cervical range of motion were measured and compared among groups and between pre- and post-test utilizing two-way ANOVA with repeated measures. Main results of the present study were as follows: 1) All variables regarding cervical alignment increased significantly in all three groups. The changes in C+P group were more significant than other two groups. 2) All variables regarding cervical muscular strength and endurance increased significantly in all three groups. 3) All variables regarding cervical range of motion increased significantly in all three groups. The changes in ROM regarding flexion and extension in C+P group were more significant than other two groups. It was concluded that all three treatments applied in this study would be effective for functional recovery of the musculoskeletal function in forward head posture patients. Especially, combination of chiropractic and PNF pattern exercise would be the most effective intervention for the patients.
The purpose of the study was to investigate the effect of shoe's soles abrasion positions on gait biomechanics and joint moment of the lower limbs. Participants between the age of 20 and 29 (Male: 10, Female: 8) were chosen as subjects. These subjects wore shoes for 40 minutes with soles that were previously worn down medially or laterally. Motion analysis system consisting of 8 infrared cameras and two force platforms were used to measure the following: center of mass(COM), ground reaction force(GRF) and lower limb’s joint moment. Significant differences in the COM and GRF were observed between lateral & medial worn shoes and non-worn shoes. In addition, significant differences in ankle and knee movements were observed. The change in shoe soles is common however there is still a lack of information regarding the effects on gait patterns, joint forces, etc. This study reveals that shoes with worn down soles can negatively influence our gait pattern. We recommend that shoes be checked regularly for signs of wear and tear and changed accordingly. Furthermore, research focusing on the effects of differently shaped shoe sole abrasion is needed to recommend how they influence an abnormal gait. In addition, further studies on the relationship of worn shoes on lower back pain needs to be conducted.
The purpose of this study was to analysis of perception types for gender equality of middle school students in P.E. class. 90 students in the specialized middle school located in K city, were selected for the subjects based on the theory of Q methodology. Q samples were 31 Q statements finally extracted from the total of 120 statements after the experts' consultation. The final 35 selections were surveyed to be forced distribution by the respondents to the statement of their positive, neutral, negative frequency distribution of the total score nine points. Factor analysis was conducted by QUANL-PC program and the following conclusions were derived by the factors centered on those over one. First, the image types for middle school students in the coed physical education class on gender equality were appeared into total of 4 categories, physical education classes without discrimination, peer-cooperative to create friendly atmosphere, physical education class to the possibility for anyone, gender equality class and there were subjective differences in each types. Second, five Q statements commonly formed among each types of the physical education on gender equality for coed middle school students were derived.
The purpose of this research is to investigate the factors affecting the performance capability of lunge movements by performing lunge movements which are commonly used as a method of instant physical movement in sports with a kinetic analysis including an EMG analysis. This research targeted 14 skilled fencers and made the subjects perform kick-lunges which allow them to go farthest from their positions and performed an analysis on such, applying a 3D motion analysis system and an EMG system. The subjects performed kick-lunges in two movements; one with a preliminary movement and the other without it and those are performed with both dominant leg and non-dominant leg. The result of this research is as follows. The lunges with a preliminary movement showed higher performance capability than those without it. Furthermore, as the level of skills gets higher, the length of lunges gets longer, and it seemed that a tactical mechanism shortening exercise performance times was used as a mechanism to control the impulse coming from such lengthened lunges. In addition, a difference appeared in mechanical factors such as moment and power in a dominant leg movement and it seemed to result from a difference in an functional capability using muscles.
The main purpose of this study was to investigate the effects of treadmill exercise and bright light exposure on serotonin expression in rat brain. Male Sprague-Dawley (SD) rats were randomly assigned into four groups (n=9 in each group), specifically, control group (CG), exercise group (EG), light group (LG), and exercise+light group (ELG). Rats in EG were subjected to treadmill exercise (5 days/week, 30 min/day), LG rats exposed (5 days/week, 30 min/day, 10,000 Lux), ELG rats subjected to treadmill exercise in combination with exposure, and CG rats remained sedentary over a four-week period. We observed a significant increase in serotonin expression in the raphe obscurus nucleu and the midbrain of rats in EG, LG, and ELG, compared to CG. Interestingly, serotonin expression was significantly increased in ELG, compared to EG and LG in the raphe obscurus nucleu via immunohistochemistry. In the western blot, it showed a increased pattern in ELG, compared to EG and LG. The overall results showed that treadmill exercise and/or bright light had positive effects on serotonin expression in the brain. Therefore, we suggest that moderate exercise or exposure to bright light during a growth child may be beneficial in brain action.
