• Journal of the Korean Applied Science and Technology
• /
• v.37 no.3
• /
• pp.509-515
• /
• 2020

The purpose of this study was to analyze the correlation between passive ankle movement range and knee joint kinetic variables during squat movement. In this study, a total of 27 subjects participated in this study, 19 men and 8 women, who had no history of the musculoskeletal system of the lower extremity. To verify the correlation between the ankle joint flexibility and the knee joint kinetic variables during deep squat, it was performed pearson's correlation coefficient and variables showing statistically significant correlation were performed by simple regression analysis at a significant level of α .05. Through this study, the relationship between the peak joint moment and joint reaction force factors that determine ankle joint flexibility and knee joint pressure was confirmed. Therefore, when applying an exercise that can generate a lot of load on the knee joint such as deep squats during strength training, checking the degree of flexibility of the ankle joint among physical characteristics to the individual may reduce the stability of the body and the risk of injury to the knee joint. It is expected to be helpful in setting the intensity of exercise that can be done.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.40 no.3
• /
• pp.59-65
• /
• 2017

The purpose of this study is to investigate the factors and effects of job stress of construction workers on construction accidents and turnover intention in order to improve the field work environment of construction industry which shows higher industrial accidents than other industries. To this end, research models and hypotheses were established based on previous research, and the questionnaire was distributed to 10 construction companies in Daejeon, Sejong, and Chungcheong provinces. The 301 data collected were performed statistical analysis such as basic statistical analysis, factor analysis, reliability analysis, correlation analysis, regression analysis, and logistic regression analysis using the statistical package (IBM SPSS 22). The results of this study are summarized as follows. First, job stress has a significant effect on accident occurrence. Among the sub-factors of job stress, there was positive (+) influence on work culture and relationship conflict between peers, and organizational system had negative influence. Job demands, compensation incompetence, and job instability were not statistically significant. Therefore, it is necessary to concentrate on the factors of work culture, organizational system, and relationship conflict in the construction site. Second, job stress has positive effect on turnover intention. Job stress, inadequacy of compensation, and work culture were positively related to turnover intention. Third, job demands have a slightly greater impact than compensatory inadequacies. The factors that make the job turnover more important are the excessive job burdens such as respect, internal motivation, responsibility rather than expectation non-conformity, time pressure, increase of work load. Therefore, in order to reduce the turnover intention of the construction worker, it is necessary to pay attention to improvement of the job requirement. Fourth, the worker's job stress could overcome by exercise and fatigue elimination, work environment management, and self-opening for others. It is necessary to establish a work environment management system for counseling and intimacy formation to open up the exercise and fatigue relief program of the workers at the construction site and to open themselves between the workers and the supervisors.

• 한국체육학회지인문사회과학편
• /
• v.51 no.5
• /
• pp.639-647
• /
• 2012

The purpose of this study was to examine the effects of varied resistance training intensities and rest intervals between training sets on integral electromyography (iEMG), repetition rate, and total work. All subjects, 14 college students, were tested one repetition maximum (1RM). Then, all subjects were weekly tested with 9 practice procedures, composed of diverse intensities (60, 75, 90% of 1RM) and rest intervals (1, 3, 5 min). As results show, to maintain the same load and target repetition maximum for an untrained person, muscular power training (90% of 1RM), muscular hypertrophy training (75% of 1RM), and muscular endurance training (60% of 1RM) should be applied with 5 min or longer rest interval periods for 3 training sets. In addition, 2 training sets with 3 min rest intervals and a set with an 1 min rest interval were capable by the subjects. Thus, at least 3 min or longer rest intervals should be applied to maintain multiple training sets. In case for muscular endurance training, which requires shorter rest intervals, the intensity of exercise should be adjusted to 60% of 1RM or less. In conclusion, depending on diverse purposes of resistance training such as improving muscular power, muscular hypertrophy, or muscular endurance, appropriate exercise intensity and rest intervals should be applied.

• Physical Therapy Rehabilitation Science
• /
• v.13 no.1
• /
• pp.53-70
• /
• 2024

Background: The conventional deadlift is a popular exercise for enhancing trunk, core, and lower extremity strength. However, its use in sports medicine is constrained by concerns of lumbar injuries, despite evidence supporting its safety and rehabilitative benefits. To optimize muscle activation using resistive bands in variable resistance therapy, we explored their feasibility in the deadlift. Design: Comparative experimental design Methods: Surface electromyography recorded muscle activity in the trunk and lower extremities during lifting, with normalization to the isometric Floor Lift using Maximal Voluntary Contraction. Kinematics were measured using inclinometer sensors to track hip and trunk sagittal plane angles. To prevent fatigue, each subject only used one of the three pairs of bands employed in the study. Results: Our study involved 45 healthy subjects (mean age: 30.4 ± 6.3 years) with similar baseline characteristics, except for years of lifting and strength-to-years-of-lifting ratio. Various resistance band groups exhibited significantly higher muscle activity than conventional deadlifts during different phases. The minimal resistance band group had notably higher muscle activity in the trunk, core, and lower extremity muscles, particularly in the end phase. The moderate resistance band group showed increased muscle activity in the mid-and end-phases. The maximum resistance band group demonstrated greater muscle activity in specific muscles during the early phase and overall higher activity in all trunk and lower extremity muscles in the mid and end phases of the deadlift (p<0.05). Conclusion: Our findings provide valuable insights into muscle activation with various resistance bands during deadlift exercise in clinical and gym settings. There appears to be a dose-response relationship between increased resistance bandwidth, external load, myoelectric activation, and range.

• Korean Journal of Agricultural Science
• /
• v.38 no.1
• /
• pp.109-113
• /
• 2011

The purpose of this study was to examine the potentiality of urban forest roads as an environment for enhancing physical fitness. Six male university students participated in the study as subjects. The subjects walked on an urban forest road for 30 minutes. As a control experiment, they also walked on a national park trail for 30 minutes. Subjects' heart rates were monitored during the walks to calculate the ratio of the average time their heart rates were within the target range (from 60% to 80% of the maximal heart rate) for Enhancing Physical Fitness. After the walks, images of the spaces were analyzed using the semantic differential (SD) method. During the walk on the urban forest road, subjects' heart rates were within the target range 63.3% of the time, and lower than the target range 36.7% of the time. During the control experiment on the national park trail, subjects' heart rates were within the target range only 23.3% of the time, and higher than the target range 76.7% of the time. From the spatial perception evaluation using the SD method, subjects' comfortable and natural feelings when they were on the national park trail were significantly greater than when they were on the urban forest trail, but there were no differences in terms of other SD descriptors, such as friendliness and likeability. The results of our study indicate that the urban forest road provides a good environment for walking to enhance physical fitness. Although not as close to nature as national park trails, urban forest roads offer similar natural environments and have a high potentiality for serving as leisure spaces for urban residents who seek physical activities.

• Journal of the Korean Society of Physical Medicine
• /
• v.11 no.2
• /
• pp.71-76
• /
• 2016

PURPOSE: The purpose of this study was to compare isometric contraction of deltoid middle fiber between elastic band and light dumbbell on various shoulder abduction angle. And this study intends to examine the compare with isometric contraction on deltoid middle fiber in various abduction angle of shoulder joint. METHODS: The participants of this study were Korean healthy adult in their 20s (n=60). The 8 channel surface electromyography was used to measure activity of the deltoid middle fiber at isomeric contraction on various abduction angle: $0^{\circ}$, $30^{\circ}$, $60^{\circ}$, $90^{\circ}$, $120^{\circ}$ of shoulder joint using elastic band: red color Theraband and dumbbell: 2kg. The data used in the analysis of the present study was the root mean square. RESULTS: The deltoid middle fiber activation was not significantly different between elastic band and dumbbell at each abduction angle. The deltoid middle fiber activation significantly increased as more to increased shoulder abduction angle in elastic band and dumbbell. CONCLUSION: The elastic band and dumbbell was to provide the similarly load to the deltoid middle fiber isometric contraction on all of the shoulder abduction angle. The deltoid middle fiber activation increased as more to increased shoulder abduction angle in elastic band and dumbbell. These results may be an important reference in development of exercise on shoulder joint.

• Journal of the Korean Applied Science and Technology
• /
• v.35 no.3
• /
• pp.940-947
• /
• 2018

The purpose of this study was to obtain data to support applied motions of bench press and to provide basic data for the efficient execution of the exercise by analyzing muscular activation through measuring electromyogram of pectoralis major and erector spinae when flat bench pressing with feet on the ground versus feet on the bench. For this study, 4 amateur bodybuilders and 2 health trainers were chosen as subjects. Surface electrodes were attached on the measuring muscles; pectoralis major and erector spinae. Motion phases were defined for the flat bench press and each subject, with a 10RM load, performed a set with feet on the ground and another set with feet on the bench. Data was analyzed in SPSS 20.0 and the following results were obtained. The placement of the feet did not affect the muscular activation of the pectoralis major during the flat bench press. however, the muscular activation of the erector spinae was different between the two positions.

• Research in Community and Public Health Nursing
• /
• v.9 no.1
• /
• pp.30-39
• /
• 1998

The purpose of this study was to identify the factors influencing health promoting lifestyle of teachers and to provide the data for efficient health management of teachers. The subjects of this study were eight hundred nine teachers, who were chosen in Choong-Buk province. Survey Questionaires for data analysis were collected through visiting or mailing from September 1 to 30, 1997. The instruments used in this study were HPLP(Health Promoting Lifestyle Profile) by Walker (1987), Internal Health Locus of Control by Walston et al. (1978), Self Esteem by Rogenberg(1965), Importance of Health by Muhlenkamp (1985), Self Efficacy by Sherer & Maddux(1982), and Family Function by Olson & Schellenberg (1985). Data were analyzed by descriptive statistics, unpaired t-test, ANOVA, Pearsons correlation coefficient and stepwise multiple regression using SPSS/PC(v. 4.01) program. The results were as follows; 1. The mean of health promoting lifestyle was total 2.53 on the average, self-actualization 2.97, nutrition 2.90, interpers 52, stress management 2.33, exercise 1.91, and health responsibility 1.82 in order. The index of total health promoting lifestyle was significantly influenced by the factors including sex, age, religion, marital status, duration of work, teaching load, education level and number of family members. 2. The health promoting Lifestyle was significantly positive correlated with Self Efficacy, Family Function, Importance of Health, Internal Health Locus of Control and Self Esteem. 3. Self Efficacy was the most influential determinant predicting health promoting lifestyle of teachers. Self efficacy, Family Function, Importance of Health, Internal Health Locus of Control and Age explained 42% of the health promoting lifestyle. Based on the above findings, it is suggested to develop nursing intervention to improve Self Efficacy, Importance of Health, Family Function of teachers enhance health promoting lifestyle. Further studies are needed to confirm these findings and to determine factors which significantly influence health promoting lifestyle of teachers.

• Journal of the Korean Institute of Navigation
• /
• v.23 no.2
• /
• pp.67-79
• /
• 1999

The purpose of this study is to provide basic date on the causes and factors related with the workload on board for Korea Seaman's Low Back Pain. The date had been acquisited through the questionaires of those and analysed in Korea Institute of Maritime and Fisheries Technology from February 10 to April 10 in 1999. The results of this study are as follows: 1. The incidence of Occupational low back pain for the recent 12 months has been recorded as 56.2% of the subject. 2. The highter Occupational satisfaction has the lower incidence of low back pain(p＜0.01). and the person who takes a rest(p＜0.05) and physical exercise regularly(p＜0.01) has lower experience of the incidence. 3. The incidence of low back pain by charateristics of vessel was turn out as 59.3% of the fishing vessel, 55.3% merchantmarine and 52.9% of the vessel of special purpose. The incidence of each department of a ship has recorded as 54.3% of Deck Dept. 59.2% of engine Dept but there was little relationship between those. And the longer period of work and on-board service has the hither incidence of the higher incdence(p＜0.01). 4. The fittness of the working table (p＜0.01) and chair(p＜0.01) has affeced the incidence of low back pain significantly 5. The higher incidence of low back pain has been experienced in case of working: in back posture, and lifting up or carrying a heavy load(p＜0.01) 6. The major cause of low back pain was turned out as excessive workload(26.5%) and stress (18.5%) ; the stress(24.1%) and excessive overwork(22.4%) for Deck dept. and excessive workload(32.3%) and bad position(21.7%) for Engine Dept(P＜0.01)

• Physical Therapy Korea
• /
• v.10 no.1
• /
• pp.109-128
• /
• 2003

This study tested whether repeated measurement of median frequency (MDF)-related variables could express the muscle power changes during a 12-week DeLome strengthening program, by using consecutive overlapping FFT (Fast Fourier transformation) and integrated EMG (IEMG) from surface EMG data for isometric and isotonic exercise. To evaluate the effect of training, the following were recorded every 3 weeks for the elbow flexors and knee extensors of 5 healthy male volunteers: MVC, lRM, limb circumference, and surface EMG during isometric MVC or isotonic contraction at 10RM load. From the EMG data, IEMG and variables from a regression analysis between MDF and time were obtained. MVC, lRM, IEMG, and initial MDF increased linearly over the training period. The fatigue index and slope of the regression line increased temporarily until the 6th week and decreased thereafter. From these results, there appeared to be enhanced neural recruitment of fast twitch fibers in the first 6 weeks and continued enhancement in the recruitment and hypertrophy of fast twitch fibers, which led to increased fatigue resistance, over the last 6 weeks. Accordingly, the MDF and IEMG analysis technique could demonstrate the effect of the program detected significant changes in both isometric and isotonic contractions. EMG analysis methods can be used to estimate the electrophysiological and histological changes in skeletal muscles during a strengthening program.