• Physical Therapy Korea
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• v.30 no.4
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• pp.275-280
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• 2023

Background: Although warm-ups before exercise are widely accepted, research on sex differences in improving hamstring flexibility is limited. Differences in the physical and physiological characteristics between males and females may result in different responses to warm-ups. Objects: This study aimed to examine sex differences in the effects of specific warm-up on hamstring flexibility. Methods: This study included 24 young adults with hamstring tightness. The participants performed five maximal knee extensions and flexions at 90° flexion of the hip, and the maximal knee extension angle was measured in real-time using a smartphone clinometer application. Results: The groups did not significantly affect the maximal knee extension angle but showed a significant effect for repetition (p = 0.002) and group-repetition interaction (p = 0.002). Males had no significant change in hamstring flexibility; however, females showed a significant increase in flexibility in the 5^th trial compared with the 1^st trial (p = 0.041). These results demonstrated sex-specific differences in flexibility improvement over time. Conclusion: The findings of this study suggest that specific warm-up can successfully improve hamstring flexibility in females. This may be due to various factors, such as muscle stiffness of the lower extremity, estrogen levels, and temperature sensitivity. In clinical settings, specific warm-up might be helpful for females who participate in sports or activities, such as running or jumping, which require a full range of motion in the hip and knee joints.

• PNF and Movement
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• v.22 no.1
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• pp.23-30
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• 2024

Purpose: Ankle instability is a common issue in both daily activities and sports, often leading to recurrent injuries. Elastic taping is a non-pharmacological intervention used to improve ankle stability. This study aimed to investigate the immediate effects of elastic taping on ankle stability, center of pressure (COP) movement, and foot pressure distribution. Methods: A single-group pre-posttest design was employed, with 30 participants included in the study. Plantar pressure and COP parameters were measured before and after the application of elastic taping. Taping was administered in three distinct patterns to enhance ankle stability. Results: Immediate effects of elastic taping were evident in COP parameters. Following taping application, there was a significant decrease in COP total displacement, COP area, and COP velocity. However, no significant changes were observed in plantar pressure parameters. Conclusion: The application of elastic taping in this study demonstrated immediate effects on ankle stability and COP parameters, indicating its potential as a viable intervention for improving balance. Further research with larger sample sizes and long-term follow-up is needed to elucidate the sustained effects of elastic taping on ankle stability.

• Journal of the Korea Society of Computer and Information
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• v.29 no.5
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• pp.85-91
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• 2024

With the current surge in leisure sports activities involving firearms and the costly shooting practices in the military, there's a growing interest in using virtual reality as a cost-effective alternative. This study proposes a system that addresses the drawbacks of existing shooting practice setups, such as dim spaces and high installation costs, by making it feasible on large display screens. The system integrates IR receivers and guns for practice, ensuring usability and efficiency through an application. Additionally, an accuracy adjustment feature enhances precise coordination recognition. As a result, this cyber light gun system offers an affordable solution for outdoor training.

• Hip & pelvis
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• v.35 no.1
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• pp.15-23
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• 2023

Purpose: Hip microinstability is defined as hip pain with a snapping and/or blocking sensation accompanied by fine anatomical anomalies. Arthroscopic capsular plication has been proposed as a treatment modality for patients without major anatomic anomalies and after failure of properly administered conservative treatment. The purpose of this study was to determine the efficacy of this procedure and to evaluate potential predictors of poor outcome. Materials and Methods: A review of 26 capsular plications in 25 patients was conducted. The mean postoperative follow-up period for the remaining patients was 29 months. Analysis of data included demographic, radiological, and interventional data. Calculation of pre- and postoperative WOMAC (Western Ontario and McMaster Universities Osteoarthritis) index was performed. Pre- and postoperative sports activities and satisfaction were also documented. A P<0.05 was considered significant. Results: No major complications were identified in this series. The mean pre- and postoperative WOMAC scores were 62.6 and 24.2, respectively. The WOMAC index showed statistically significant postoperative improvement (P=0.0009). The mean satisfaction rate was 7.7/10. Four patients with persistent pain underwent a periacetabular osteotomy. A lateral center edge angle ≤21° was detected in all hips at presentation. We were not able to demonstrate any difference in postoperative evolution with regard to the presence of hip dysplasia (P>0.05), probably because the sample size was too small. Conclusion: Capsular plication can result in significant clinical and functional improvement in carefully selected cases of hip microinstability.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.2
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• pp.29-34
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• 2024

Since the outbreak of COVID-19, there has been a surge in sports conducted through online platforms due to the increase in remote and non-contact activities. Billiards, being suitable for online platforms, has received much attention, leading to research on detecting the position and trajectory of balls. In this paper, we propose a new method utilizing machine vision to detect the position of the balls accurately. The proposed method detects the outline of the ball using the Canny edge detection and then employs simple correlation to determine its position. This correlation-based approach offers satisfactory system performance and is easily applicable in practical systems due to its low implementation complexity and robustness to noise.

• Korean Journal of Applied Biomechanics
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• v.26 no.2
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• pp.237-242
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• 2016

Objective: The purpose of this study was to compare the joint movements and muscle activities of novices according to pedal type (flat, clip, and cleat pedal). Method: Nine novice male subjects (age: $24.4{\pm}1.9years$, height: $1.77{\pm}0.05m$, weight: $72.4{\pm}7.6kg$, shoe size: $267.20{\pm}7.50mm$) participated in 3-minute, 60-rpm cycle pedaling tests with the same load and cadence. Each of the subject's saddle height was determined by the $155^{\circ}$ knee flexion angle when the pedal crank was at the 6 o'clock position ($25^{\circ}$ knee angle method). The muscle activities of the vastus lateralis, tibialis anterior, biceps femoris, and gastrocnemius medialis were compared by using electromyography during 4 pedaling phases (phase 1: $330{\sim}30^{\circ}$, phase 2: $30{\sim}150^{\circ}$, phase 3: $150{\sim}210^{\circ}$, and phase 4: $210{\sim}330^{\circ}$). Results: The knee joint movement (range of motion) and maximum dorsiflexion angle of the ankle joint with the flat pedal were larger than those of the clip and cleat pedals. The maximum plantarflexion timing with the flat and clip pedals was faster than that of the flat pedal. Electromyography revealed that the vastus lateralis muscle activity with the flat pedal was greater than that with the clip and cleat pedals. Conclusion: With the clip and cleat pedals, the joint movements were limited but the muscle activities were more effective than that with the flat pedal. The novice cannot benefit from the clip and cleat pedals regardless of their pull-up pedaling advantage. Therefore, the novice should perform the skilled pulling-up pedaling exercise in order to benefit from the clip and cleat pedals in terms of pedaling performance.

• Korea journal of population studies
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• v.34 no.2
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• pp.65-90
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• 2011

This study aims to investigate how labour time pressure is associated with leisure selection and managing leisure hours, especially focusing on health related behavior issues. I have employed Time Diary data of 9,891 Korean respondents who were married and living in the cities and metropolitan area (female 51.8%, age range 20-69, average age=45.7). Leisure activities, as dependent variable, which were introduced in time diary data and the amount of time spent for such leisure were estimated. Results show that in time pressing situations(having long labour hours), leisure activities, and the hours spent for leisure tend to suffer. Especially, solitary leisure, like exercise or walking was very likely to sacrifice under time pressure. Moreover, in terms of sports or exercise, results suggest that not only time resource but also social and economic resources seemed to required for actually initiating the activity. Therefore, simply having more time (less tiome for work) may not be enough for promoting exercise for this population. Strategies and social policies that are aiming for promoting healthy behavior needs more closer look on leisure situation and people's desire for optimizing their time.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2005.10a
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• pp.189-194
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• 2005

The interest of people is rising on water leisure and the population of water sports is increasing with expanded nationwide roads and 5-day work system for income elevation. However, there are many discussions about the way to prevent the accident related to water leisure activities. Water Leisure Safety Regulation was enacted in 1999 as a part of the way and revised in 2005. Therefore it needs to grasp the present state of water leisure activities and analyze the actual condition of consciousness. For the analysis. the question survey was conducted on water leisurers in the focus with regulation of the revised so that the degree of relevance and correlation between mutual variables were analyzed by Frequency and Crosstabs. From this study we found that more than $60\%$ of water leisurers thought registration, safety instruction, insurance, and safety inspection necessary and there was a characteristic common inclination to all for necessity to impose legal controls on water leisure activities as the level of dissatisfaction for water leisure apparatus and cognition for necessity of insurance was high.

• Korean Journal of Applied Biomechanics
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• v.24 no.2
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• pp.139-149
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• 2014

The purpose of this study was to evaluate the effect of angle change of forefoot's adhesive outsole on the electromyographic activity (EMG) of the erector spinae and selected lower limbs muscle during downhill walking over $-20^{\circ}$ ramp. Thirteen male university students (age: $25.4{\pm}3.9$ yrs, height: $176.2{\pm}5.1$ cm, weight: $717.4{\pm}105.0$ N) who have no musculoskeletal disorder were recruited as the subjects. To assess the myoelectric activities of selected muscles, six of surface EMG electrodes with on-site pre-amplification circuitry were attached to erector spinae (ES), rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), lateral gastrocnemius (LG), and medial gastrocnemius (MG). To obtain maximum EMG levels of the selected muscles for normalization, five maximum effort isometric contraction were performed before the experimental trials. Each subject walked over $0^{\circ}$ and $20^{\circ}$ ramp with three different forefeet's EVA outsole (0, 10, $20^{\circ}$) in random order at a speed of $1.2{\pm}0.1$ m/s. For each trial being analyzed, five critical instants and four phases were identified from the recording. The results of this study showed that the average muscle activities of MG and LG decreased in $20^{\circ}$ shoes compared to $0^{\circ}$ and $10^{\circ}$ ones in the initial double limb stance (IDLS). In initial single limb stance (ISLS) phase, the average muscle activities of ES increased with the angle of forefoot's adhesive outsole, indicating that the increment of shoes' angle induce upper body to flex anteriorly in order to maintain balance of trunk. In terminal double limb stance (TDLS) phase, average muscle activities of TA significantly increased in $20^{\circ}$ outsole compared to $0^{\circ}$ and $10^{\circ}$ ones. There was no external forces acting on the right foot other than the gravity during terminal single limb stance (TSLS) phase, all muscles maintained moderate levels of activity.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.1119-1126
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• 2023

This study measured the social value of social economy enterprises in Incheon Metropolitan City using the Social Value Index (SVI) developed by the Korea Social Enterprise Promotion Agency. The results showed that the social value orientation of the business activities of SSEs averaged 9.3 out of 15 points, and their innovation efforts were 8.0 out of 10 points. The average monetary and non-monetary social contribution efforts of SSEs was 5.1 out of 10. When comparing the average sales and social value scores by industry, the manufacturing sector shows that social enterprises have higher average sales and social value orientation of business activities, but lower social return efforts. Social work facility management and business support services have high average sales, but low social value orientation of business activities and efforts to make monetary or non-monetary social contributions. On the other hand, education services; arts, sports, and leisure-related services; and publishing, video, broadcasting, communication, and information services have lower average revenues but higher social value orientation of business activities. These SVI indicators are well utilized by local governments, but not yet by the central government. In the future, governments and public institutions should reflect the differences between sectors when formulating policies for social enterprises.