This study was aimed at investigating the effect of head-tilt angle on autonomic nerve modulation immediately after a single bout of exercise in twenty-three healthy young males(age 21.96 ± .4 yrs). Post-exercise HRV was measured on supine(SUP), -15°head-down tilt(HDT), and +15°head-up tilt(HUT) followed by 20 min aerobic exercise with moderate intensity(40% of VO2max). As results, heart rate recovery during post-exercise on each tilt angle(SUP vs. HDT vs. HUT) had no significant difference(p> .05). Also, there were no significant difference in time and nonlinear domain index of HRV. On spectral analysis; however, frequency domain index(HF, LF/HF ratio, HF/TP ratio, HF nu, LF nu) had significant difference(p< .05) on each tilt angle at recovery. Especially, PNS reactivation index (HF, HF/TP ratio, HF nu) had significant increase on HDT compared to HUT(p<. 05) while SNS activation index (LF/HF ratio, LF nu) had significant decrease on HDT compared to HUT(p<. 05). Furthermore, there were significant interaction between recovery time elapsed and each tilt angle (except for HF/TP ratio). In conclusion, -15°head-down tilt promotes the effective cardiac vagus nerve reactivation immediately after a single bout of aerobic exercise.
PURPOSE This study aimed to compare body composition, physical fitness, maximum muscle strength, and blood lactate concentration according to the level of aerobic capacity in Keirin cyclists. METHODS Forty-four Keirin cyclists participated in this study and were divided into three groups: the top 20% VO2max group (TG, n=9), the middle 20% VO2max group (MG, n=9), and the low 20% VO2max group (LG, n=9). The study measured body composition, physical fitness, maximum muscle strength, and blood lactate concentration in Keirin cyclists. Differences between groups were determined using one-way ANOVA analysis. RESULTS Body weight, percentage of body fat, and body mass index were significantly higher in the LG than in the TG and MG. The vertical jump and maximum muscle strength were significantly higher in the TG and MG than in the LG. Additionally, blood lactate concentrations immediately after exhaustive exercise and during the 5-minute recovery periods were higher in the LG than in the TG and MG. Moreover, the time to exhaustion, HRmax and maximum power were the highest in the TG. CONCLUSIONS Our findings suggest new information that levels of aerobic capacity in male Keirin cyclists might be a crucial predictor of cycling performance and recovery ability.
Purpose This study was designed to investigate the effects of weight-bearing exercise and CareRing treatment on cardiovascular responses, popliteal vein functions, and vascular elasticity of 30-40s women who had worked longer than eight hours a day in a standing position. Methods Thirteen subjects participated in 30 min of standing up treatment (STAND), weight-bearing exercise treatment (EX), and weight-bearing exercise with CareRing treatment (EX+RING). Each subject took part in the three trials repeatedly in a counter-balanced order and proceeded with a wash-out period of at least one week between the respective trials. Results The main results were as follows: 1) Significant reduction in EDV, no change in the diameter of popliteal vein, trend of reduction in blood flow of popliteal vein, and increased baPWV, indicating reduction of vascular elasticity of whole body, were shown in the STAND. 2) CO and EF increased significantly, and TPR decreased significantly in the EX. Blood flow velocity and blood flow volume of popliteal vein increased significantly, and baPWV decreased significantly from immediately after the treatment throughout the recovery phase in the EX. 3) HR, CO, and EF increased significantly in the EX+RING. Blood flow velocity and blood flow volume increased significantly in the EX+RING. Diameter of popliteal vein increased significantly immediately after the treatment and decreased significantly at 40 minutes of recovery. TPR and baPWV decreased significantly immediately after treatment compared to the STAND. Conclusions It was concluded that weight-bearing exercises would be effective in preventing venous or cardiovascular diseases occurred due to long-standing in 30-40s women, who are at high risk for such diseases. Furthermore, it would be more effective to combine pressure treatment with CareRing during weight-bearing exercises.
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.
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.
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 this study was to describe psychological changes and variables of injured elite athletes during sport injury rehabilitation. 5 injured elite athletes were selected as participants, and open-ended questionnaires, participant observation, and in-depth interview were used for collecting data. Results from the data were analyzed through transcription, coding, and categorization with inductive method. To validate the results of this study, triangulation, in-depth description, member checks, and peer debriefing were used, and findings of this study were as follow. The participants showed negative psychological state such as fear of return to play and anxiety during the initial rehabilitation program, but their psychological state was changed positively such as recovery of confidence and desire of return to play at the end of program. However, the specific psychological changes of each participant showed several differences according to participant's surrounding environment and situation during the rehabilitation program. All findings have important implications for implementing and developing rehabilitation program, so needs to be investigated further.
PURPOSE Through analysis, this study reports on occurrences of children and adolescents’ sports accidents and presents measures to prevent, cope with, and manage school sports accidents. METHODS The study used both quantitative and qualitative methods. First, a frequency analysis was conducted using 284,429 safety accident data of the School Safety and Insurance Association (SSIA). Second, the inductive analysis method was applied to in-depth interviews conducted with eight teachers. RESULTS , accidents are characterized as follows: 1) At the school level, accidents have increased significantly every year in a large proportion of elementary and middle schools. 2) The span of time spent on sports was large. 3) Accidents happened at playgrounds and auxiliary facilities. 4) Accidents happened during kindergarten play and ball sports in schools. 5) The descending order of days with the most accidents was Thursday, Tuesday, Friday, Wednesday, Monday, Saturday, and Sunday. 6) Rather than a certain month, accidents happened across the school semester. 7) Most accidents occurred from 10 a.m. to 2 p.m. Second, field teachers’ stories were categorized into the following topics. 1) School accidents can occur anytime, anywhere. Whether mild or serious, they still had the burden of inevitable accidents. 2) Required: were prompt response and handling by appropriate teachers; timely treatment and recovery cost support; also procedurally simplified handling by SSIA was helpful. 3) Avoiding accidents requires the following:: regular operation of safety education programs; daily promotion of teachers’ preventive observation and close guidance; and active role reinforcement of SSIA and policy support. CONCLUSIONS Finally, measures to prevent, cope with, and manage school safety accidents were proposed.
PURPOSE The purpose of this study was to investigate the current injury status and traits, including damage area, cause of damage based on the situation, and type of occurrence by age group for middle and high schools, university, and professional athletes, in record competition sports (swimming, track and field, and weightlifting). METHODS The study included 503 athletes enrolled in the Korean Sport & Olympic Committee in 2020, and an online survey was conducted using the R statistical program. RESULTS Approximately 38.4% athletes suffered injuries with weightlifting (0.81 times at university) and weightlifting (7.02 times at university) during training. The lower extremities were the most affected areas in all age groups (53.8% in middle school, 48.6% in high school, 44.4% in university, and 47.4% in professional). The causes of damage found to occur most frequently were ‘lack of physical strength, overuse or lack of rest, and recurrence’ and external factors, including ‘facility programs and weather problems.’ The results showed that internal factors during training were mostly associated with ‘overuse or lack of rest and excessive attempts at skills’, while external factors were found to occur in ‘weather problems’. According to the classification of each event, the top priority of frequent damage according to the damaged area was skin bleeding of the head in swimming and muscle inflammation in the torso and upper and lower extremities. Track and field resulted in muscle inflammation in the head, torso, and upper and lower extremities. Weightlifting caused damage to the head and torso, resulted in spinal diseases (disc, spinal stenosis, etc.), and muscle inflammation in the upper and lower extremities. CONCLUSIONS This study highlighted changes in the training environment and training environment, including level-specific physical training, reinforcement programs, scientific access to specific skills, sufficient rest and recovery, and continuous improvement of facilities and equipment.
The purpose of this study was to analysis of moving distance during games, time and heart rate for hockey games using GPS (global positioning systems) by positions in Korea national female athletes. The subjects were Korea national female hockey players (n=13) including 4 forwards, 4 midfields, and 5 fullbacks that participated in five Korea vs. Japan international games. All subjects were wearing GPS throughout the games. The results were as follows: Firstly, the average total travel distance per game was approximately 5.7km and higher in the second half. Physical movement in the games was not different from positions where 70% of physical movement was performed at low intensity and 30% at moderate and/or vigorous intensity, suggesting that the subjects; physical movement was performed at the appropriate level of exercise intensity. Secondly, during the game, the subjects performed physical movement faster than 11km/h for 22 minutes, indicating that the subjects could maintain their physical movement at a relatively faster speed throughout the games. In particular, midfields showed a greater amount of physical movement at moderate speed. Thirdly, the average exercise heart rate was 145bpm, which was equivalent to 60% of HRmax. The subjects maintained their average exercise heart rate greater than 150bpm (above 60% of HRmax) for 40 minutes during the games, indicating that the players had an ability to maintain physical movement at high intensity throughout the games. In conclusion, in spite of the fact that Korea national female hockey players have an ability to maintain physical movement at a relatively faster speed and higher intensity, their physical movement and performance are often affected. Therefore, it is necessary to develop and apply the specific interval training program for national female hockey players that can facilitate the faster recovery from the repetitive physical movement requiring power and speed at high intensity.
