The purpose of this study was to investigate effects of carbon nanotube-based insole on the resultant joint moment and muscle activity of the lower extremity during drop landing. Ten males with no known musculoskeltal disorders were recruited as the subjects. Two digital camcorders and one force plate were used to obtain 3-D kinematics and kinetics of the lower extremity. To assess the myoelectric activities of selected muscles, five surface electrodes were attached to the right side of the lower extremity. For each dependent variable, paired t-test was performed to test if significant difference existed between with carbon nanotube-based insole(CNT) and ethylene vinyl acetate-based insole(EVA) conditions(p<.05). The results showed that average and peak IEMG values from RF, TA, MG, and LG in CNT were lower than corresponding values in EVA. Although no significant difference in resultant joint moment was found between two conditions, a decrease in the knee extension moment was found with CNT. This indicates that wearing carbon nanotube-based insole may help to decrease impact force and to control excessive flexion movement of the knee joint during landing.
The purpose of this study was to examine psychological capital acquisition through Asian Games Participation. 17 of national women football players were completed Psychological Capitals Questionnair. The psychological capital consists of optimism, psychological skills, self-management, collective efficacy, and performance perception was investigated after the team call-ups and before the team-release. The data was analyzed by paired t-test. As results, Korean women football players’ collective efficient and performance perception showed a statistical significance at the beginning of the team call-ups but optimism, psychological skills, and self-direction did not show statistic significances. The team-harmony, interpersonal-management, team-power, sufficient training, trust in coach, efficient communication, and psychological football factors, which were subfactor of football players’ psychological capital, showed statistical significances. However, confidence, concentration, goal-setting, imagery, willpower, anxiety-control, mental-management, life-management, training-management, innate-behavior management, physical-management, football skills, mediative skills, and football intelligence factors did not have statistic significances. These results demonstrate that effects of mega sporting events-like experiences and psychological factors’ variability and inflexibility according to weather changes should be considered when it comes to discussion of psychological factors regarding players’ performance. It is expected that this study would be a fundamental resource for understanding of psychological influences through participations in mega sporting events and discussions about further psychological interventions for teams with environmental consideration as well as methodological developments which could measure effects of the psychological interventions.
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.
The purpose of this study was to examine the effect of dietary creatine and leucine supplementation on protein synthesis and functional properties of skeletal muscle during 8 weeks of resistance exercise. Thirty two male Sprague-Dawley rat(5 weeks old) were randomly divided into four groups(8 rats per group): sedentary control group(CON), execise group(E), exercise with creatine supplementation group(EC), exercise with creatine, leucine supplementation group(ECL). Exercise groups were trained to climb a ladder with a weight secured to their tails(3day/week). The supplementation was administrated daily through oral gavage. Creatine supplementation was given at 250㎎/㎏/day. Creatine+leucine supplementation was given at 250+250㎎/㎏/day. All exercise groups presented significantly lower epididymal fat mass than CON(p<.05). E presented significantly higher plantaris mass than CON(p<.05). All exercise groups significantly presented higher FHL mass than CON(p<.05) and E presented higher FHL mass than EC, ECL(p<.05). EC, ECL presented significantly lower expression of Akt/PKB protein than CON, E(p<.05). There was no difference in the expression of mTOR protein. The results suggest that the creatine and leucine supplementation does not promote any additional hypertrophic effect on resistance trained skeletal muscle. But, creatine and leucine supplementation might have a potential benefit on skeletal muscle hypertrophy through the activation of protein synthesis.
The purpose of this study was to classify high school baseball players as superior or inferior group by Functional Movement Screen(FMS) and to provide basic information for finding great pitcher and improving exercise performance by comparing and analyzing the pitching motion. The results of this study are as follows. The inferior group’s center of mass(COM) moved significant on the left side than superior group at heel contact(HC), ball release(BR), and follow throw(FT)(p<.05). There were no significant difference in linear velocity of shoulder, elbow and wrist between two groups, but inferior groups showed large difference in each joint. The superior group controled rotation of pelvis at HC and showed significant higher knee extension at BR and FT than inferior group(p<.05). The angular velocity of superior group’s throwing arm were higher in acceleration period(p<.05). Taken together based on the results, the players who have higher muscle function showed great pitching motion, so we can conclude that FMS could be useful for evaluating the potential of pitcher.
PURPOSE This study investigated the effects of 12 weeks of clubbell and stepbox training on physical fitness, badminton skills, and fatigue in male badminton, grade A (top grade) club members aged 20–30s, with over 5 years’ experience. METHODS Participants in a training group (TR: n=15) engaged in 12 weeks of clubbell and stepbox circuit training involving maximum 8–12 reps of clubbell exercises and stepbox exercises at over 77% of HRmax for 50–55 min/sessions three times a week. Participants in a control group (CON: n=15) maintained their normal lifestyle pattern during the same intervention period. Dependent variables were measured and compared using repeated measures two-way ANOVA. RESULTS The main results were as follows: 1) The groups showed no significant differences in body composition. 2) Regarding physical fitness, VO2max, relative peak power, relative average power, grip strength, push ups, repeated jump squats, SSPT (seated single-arm shot-put test), 10 m sprint, and hexagon agility increased significantly in the TR, while push ups decreased significantly in the CON. 3) As for badminton skills, forehand clear accuracy, badminton agility, badminton endurance, and smash speed increased significantly in the TR. Forehand clear accuracy decreased significantly in the CON, but badminton agility and smash speed increased significantly. 4) The groups showed no significant differences in fatigue. CONCLUSIONS In male badminton club members aged 20–30s, 12 weeks of clubbell and stepbox circuit training effectively improved physical fitness and badminton skills. However, lack of any improvement in body composition and fatigue warranted further research in these areas.
PURPOSE This study aims to investigate the effects of a 12-week equipment-based Pilates training on physical fitness, cardiovascular function, and vascular endothelial function in obese middle-aged women. METHODS Twenty-four women, aged 30-40 years with a body mass index ≥ 25 and percent body fat ≥ 30% were randomly assigned to one of two groups: the Pilates training group (TR; n=12); and control group (CON; n=12). The TR participants underwent three 50-minute equipmentbased Pilates training sessions per week for 12 weeks. Participants in the CON maintained their normal life patterns for the same intervention period. Variables regarding physical fitness, cardiovascular function, and vascular endothelial function were measured and compared pre-test and post-test u a two-way ANOVA with repeated measures. RESULTS The main results of the study were as follows: 1) Regarding physique and body composition, participants’ body weight, body mass index, fat mass, percent body fat, waist circumference, hip circumference, and waist-to-hip ratio decreased significantly in the TR. 2) Regarding physical fitness, muscle strength, muscular endurance, flexibility, and cardiorespiratory endurance increased significantly in the TR. 3) Regarding cardiovascular response, SV increased significantly in the TR. 4) Regarding vascular endothelial function, blood vessel diameter at rest and during vasodilation as well as blood flow volume during vasodilation decreased significantly in the CON, resulting in a significant interaction between group and test in FMD percentage. CONCLUSIONS It was concluded that the 12-week equipment-based Pilates program improved the physical fitness and vascular endothelial function in obese middle-aged women.
Purpose This study aims to investigate the experience of service yips in badminton players in depth through using grounded theory method. Methods We collected data from in-depth interviews with 14 participants in total, consisting of badminton players who experienced service yips, their doubles partners and coaches. The collected raw data were analyzed base on derive transcription, coding and paradigm models through grounded theory method. Results First, as a result, 59 concepts, 31 subcategories and 15 categories in regard to badminton service yips were deduced from open coding. Second, in axial coding, it was structured in a paradigm model by categories such as service yips, service mistakes, service proficiency, service anxiety, the imprinting experiences, the importance competition, the pressure of achievement, service practice, psychological control, tactical handling, support from partners, leaders’ coaching, advice from experienced ones, overcoming yips and persistent yips. Third, selective coding resulted in ‘Badminton service yips’ as the core category of this study. ‘Badminton service yips’ is a chronic performance impairment associated with badminton players making severe errors in swing motion on a service not intended by them that it is due to physiological or psychological symptoms such as hand tremors, overall body stiffness, arms stiffness, overstress, overanxiety, and concern over service mistakes. Conclusions We expect our study can be a theoretical foundation for understanding and explanation of ‘Badminton service yips’ and a useful reference for badminton players suffering from psychological difficulties caused by their service yips. The findings in this study should be considered for the development of potential strategies for overcoming the badminton service yips.
Purpose This is to provide essential data for training necessary for sweeping through the analysis of muscle activity generated at this time and how much sweeping and what trajectory moves the stone when the movement of the stone is controlled through sweeping. Methods To check and record the distance between the stones by checking the stop position of the stone made by sweeping each section, the length (progress distance) and width (progress direction) were recorded using a reference table and a record preparation table. With the EMG attached, a total of 60 sweeps were made 20 times each from the beginning of the section to the end of the section. Sweeping subjects were asked to sweep as much as possible under the same conditions in all three sections. Results As a result of the study, the muscle mobilization patterns of the 1st and 2nd sections of the stone with the faster speed and the 3rd section with the stone's slower speed appeared differently. It was confirmed that the sweeping motion of curling is a motion that is used evenly among the muscles of the upper extremity, and it can be verified that it is a suitable item for the development of upper body muscles. Also, the right deltoid's muscle activity rate during push and the right triceps brachii during pull was high. Conclusion Each section of the stone's sweeping effect is an exercise that has many variables, such as changes in atmospheric temperature and humidity, changes in ice temperature, temperature-size-number of pebbles, and the edge state-resilience of stones, etc. It is judged that experience can cope with these variables and requires training.
