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 conducted a longitudinal analysis of physical activity levels and characteristics of middle-school boys and girls over a three-year period before and after the COVID-19 pandemic. METHODS This study used a sequential mixed-methods research design. In the quantitative study; three-dimensional accelerometers were used to measure weekly physical activity and sedentary time over three years (2019, 2020, and 2021) among 33 middle-school boys and girls, and the data were analyzed using repeated measures analysis of variance. In the qualitative study, data were collected and analyzed through focus group interviews with five participants. RESULTS The quantitative study indicated a significant increase in sedentary behavior and significant decrease in low-intensity activity and MVPA during the first year of the COVID-19 pandemic. In the second year of the pandemic, no significant difference was observed in sedentary behavior, low-intensity activity, and MVPA compared to the data collected in the first year. During the pandemic’s first year, qualitative study identified the following physical activity problems: “lockdowns,” “sedentarization of leisure,” and “reduced structured physical activity.” The following reasons were identified for the lack of improvement in physical activity during the second year: “intensified sedentary lifestyle habits,” “weak social networks,” and “lack of energy to exercise.” CONCLUSIONS The COVID-19 pandemic has led to a significant decrease in physical activity and a significant increase in sedentary behavior among middle-school students in South Korea, and even as the environments for physical activity have recovered, the physical activity problems of the early stages of the pandemic have not improved.
PURPOSE This study investigated the impact of underweight and hand grip strength (HGS) levels on the risk of all-cause mortality in older adults. METHODS Data from the 2006 baseline and 2020 follow-up assessments of the Korean Longitudinal Study of Aging (KLoSA), involving 3,009 older Koreans (≥65 years) were used in the study. Participants were categorized based on body mass index (BMI) as underweight, normal, overweight, or obese and grouped according to the Asian Working Group Sarcopenia criteria into high or low HGS. Cox proportional hazard models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI) of all-cause mortality according to BMI and HGS categories. RESULTS During the 11.3±4.0 years follow-up period, 1,334 deaths from all causes occurred. The risk of death by BMI and HGS level was analyzed. The results showed that the risk of death in the overweight and high HGS group (HR=0.773, p=.016) was significantly lower than that in the normal weight & high HGS group (HR=1). In comparison, the risk of death in the underweight & low HGS group (HR=1.930, p<.001) and the normal weight & high HGS group (HR=1.225, p=.014) were significantly higher than normal weight & high HGS. However, the risk of death in the underweight and high HGS group showed no significant difference compared to the normal weight and high HGS group. CONCLUSIONS The current findings suggest that improving muscle strength through regular exercise may be important in preventing the risk of all-cause mortality due to being underweight.
PURPOSE Increased body mass index (BMI) increases ankle instability and adversely affects human movement. This study aims to compare and analyze the muscle function and proprioception of the ankle joint based on Body Mass Index (BMI) to determine potential differences. METHODS Twenty-eight healthy male and female college students were categorized into overweight (≥ BMI 23) and normal (< BMI 23) groups. Measurements included BMI, isokinetic strength of dorsiflexion, plantarflexion, eversion, inversion, ankle joint range of motion, and ankle joint proprioception. RESULTS In dorsiflexion, right 30°/sec (p=.035), left 30°/sec (p=.009) and right 120°/sec (p=.011); in plantarflexion, left 30°/sec (p<.001), right 120°/sec (p=.007) and left 120°/sec (p=.006) in ankle inversion, left 30°/sec (p=.001), right 120°/sec (p=.021) and left 120°/sec (p=.007), left 30°/sec (p=.014), 120°/sec (p=.001) in ankle inversion-eversion ratio, right (p=.003) and left (p=.003) in ankle joint range of motion, right (p<.001) and left (p=.022) in total proprioception, and left (p<.001) in left-right proprioception were significantly different between the normal and overweight groups. CONCLUSIONS It was found that the overweight group had lower muscle strength, joint range of motion, and proprioceptive control function of the ankle joint than the normal group according to BMI. Therefore, exercise programs should be provided to strengthen the periarticular muscles involved in ankle movement, such as the tibialis anterior, soleus, and peroneus longus, and to control dynamic proprioception to prevent ankle injuries and function of the ankle joint according to BMI.
PURPOSE This study was designed to propose a quantitative base training evaluation method through alpine ski training monitoring using a triaxial accelerometer. METHODS Twelve Korean alpine ski athletes, six each in France and New Zealand, participated in this study. Activity data during training and daily living were collected for 7 days via the Actigraph GT9X. The collected data were downloaded through ActiLife Ver 6.13.1. Energy expenditure was calculated with Freedson (2011), and the resting metabolic rate was corrected using the Harris & Benedict (1918) formula. Further, the physical activity intensity classification criteria and METs formula of Freedson (1998) were used to classify hourly activity intensity. The collected data were organized by date, time, intensity, and energy expenditure using Microsoft Excel 2016. Differences between weekdays vs. weekends and skiing vs. physical training were analyzed through a paired sample t-test using Windows SPSS 23 with a significance level of a=.05. RESULTS First, both groups showed repetitive on and off high-intensity activities during scheduled ski training and competition. Second, moderate-intensity activities accounted for an average of 6-10%, and the weekly total time and intensity of MVPA was very high. Finally, the group from France showed differences in total energy expenditure during weekdays vs. weekends (p<.05) and the energy expenditure of both ski training and physical training during weekdays vs. weekends (p<.05). The New Zealand group showed a difference in total energy consumption during weekdays vs. weekends (p<.05). CONCLUSIONS A systematic training program based on quantitative training evaluation should be developed for alpine ski athletes to maintain proper rest and exercise intensity levels.
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.
Purpose The purpose of this study is to identify the negative effects of long-term exercise (training and competition) suspension of male elite athletes due to compulsory military service on athletic performance, and to provide a basis for enhancing the importance of providing support systems and social conditions for maintaining athletic performance. Methods In this study, 17,418 male athletes aged 18 to 21 who were registered as athletes for the Korean Sports & Olympic Committee from 2003 to 2005 were enrolled. The athlete registration data includes information about the athlete's gender, age, sport and affiliation. According to the continuity of registration and belonging information, the compulsory military service type was classified into a manipulator. According to the form of Compulsory military service performed by male elite athletes, the return rate was confirmed and the career (year) was calculated. Results As a result of the survey, 12.49% of the athletes who served as general soldiers returned to the athletes after compulsory military service, showing a relatively low return rate compared to 78.91% of the Korea Armed Forces Athletic Corps, 76.55% of the National Police Agency's sports team, and 71.43% of the social service. Also, Athletes who served as general soldiers had a career of 2.46 years (± 1.94), while the Korea Armed Forces Athletic Corps was 10.21 years (± 3.58), the National Police Agency's sports team was 9.45 years (± 3.26), and the social service was 5.86 years (± 4.06), The exemption was 11.08 years (± 2.27), and the compulsory military service exception was 9.79 years (± 5.55). Conclusions Male elite athletes' decrease in athletic performance after compulsory military service is a natural result, as confirmed through the results of this study, and it is necessary to seek a support system between compulsory military service to maintain athletic performance.
Purpose This study was conducted to analyze the differences of physical characteristics focused on the physique, strength, and power for cycling national athletes (Sprint cyclists and Road race cyclists). Methods We measured various factors (e.g., height, weight, body fat ratio, thigh circumference, waist circumference, anaerobic power, isokinetic muscular strength, muscle power, squat jump by 1RM intensity, and so on) for a total 11 male cycling national athletes (5 Sprint cyclists and 6 Road race cyclists). Results First, the body composition showed the significant differences only in weight (p=0.31) and BMI (p=.001) for Sprint cyclists. Second, the values of the anaerobic power for the Sprint cyclists were significantly higher than those for the Road race cyclists only at peak power (p=0.28), whereas there was no significant difference in average power, isokinetic muscular strength, and muscle power between the two groups. Third, the isokinetic trunk flexion muscle (p = .016) for the Sprint cyclists were significantly higher than those for the Road race cyclists. Fourth, the significant difference in Time to Peak Torque was not found between two groups. Fifth, the values for the Sprint cyclists showed the significant difference in all 5 intensity groups (0%, 30%, 50%, 60%, and 80%) (p=.001) of the squat jump. Also, there was a statistically significant difference only in 0% velocity between the two groups, except for exercise intensity. Conclusions From the various measures between two groups, the Sprint cyclists relatively showed the high weight, BMI (muscle mass), and maximum power. Additionally, the isokinetic trunk flexion muscle and the squat jump were higher in the Sprint cyclists than the Road race cyclists. These data may be used as basic data to improve the physical fitness factors related to the athletic performance of the athletes by reflecting them in the effective training plan and evaluation of the athletes.
The purpose of the study is to find the impact of social and economic factors in physical activity of children and youth. This study utilized the data from 4th Korean Children and Youth Panel Study(KCYPS), and the analysis were carried out based on the starting sample of 2,009 from ‘the elementary 4 panel’ and 1,978 from the ‘middle school 1 panel’ and 1,984 from the ‘high school 1 panel’, 5,971 full data were used in the final analysis. Data were processed using hierarchical regression analysis and it was statistically validated at the significance level of 0.05. First, Pearson r and Spearman ρ showed that all variables are statistically significant correlations. Second, among the first factors of personal and family characteristics, household income level(B=.113), family composition(B=-.049) and parental education (B=.060) were found on a significant impact on the movement of physical activity time, parental education (B=.027) was found on a significant impact on the subjective evaluation of physical education grades. Third, among the second factors of community-level characteristics, Gini coefficient (B=-.810), wealth concentrating (B=.120) were found on a significant impact on the movement of physical activity time, the Gini coefficient (B=-0.315) was found on a significant impact on the subjective evaluation of physical education grades. Additional factors that determine the coefficient of variation in the level 2 were found to be 0.623 and 0.001 respectively. Therefore, second factors of community-level characteristics are added such as Gini coefficient, wealth concentrating were explained to children and youth exercise time during physical activity 62.3%(p<.01) and subjective evaluation of physical education in grades 0.1%(p<.01). predictive power to
