• 제목/요약/키워드: Flexion time

검색결과 336건 처리시간 0.022초

대학 야구 강의를 통한 초보자의 타격 동작 변화 분석 (The Analysis on the Changes in Beginners Batting Movements through Undergraduate Baseball Lectures)

  • 천영진
    • 한국운동역학회지
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    • 제22권3호
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    • pp.277-284
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    • 2012
  • The purpose of this study was to find out the changes in beginners' batting movements after taking undergraduate baseball lectures, by comparing and analyzing the speed of bat, the angle of body and its segments, the angular velocity and so on. For this purpose, the author picked up five undergraduates who had not taken baseball lectures, and conducted three-dimension computerized tomography twice on them, that is, before and after taking baseball classes, with eight infrared cameras and two force platforms. The conclusions are, first, the time required for swing was shortened after taking the classes. Second, the maximum velocity of the bat-end was increased. Third, at the time of impact, while the rotation angles of the pelvis and the tip of left foot were increased, the left elbow had more flexion after the classes. Fourth, the size of ground reaction force was increased at the point of swing where the ground reaction force of left foot became maximized. As we can infer from these conclusions, beginners' hitting movements before taking baseball classes tended to swing only with the arms, without waist rotation and weight shift of the lower body, but after the classes, their movements were proved to be corrected into the swing using the lower body. For the future studies, the author expects a research in a close to real environment by using pitching machine.

경부통증을 호소하는 고등학생에게 적용한 밸런스 테이핑 요법의 효과 (Effect of Balance Taping Therapy on Neck Pain in High School Students)

  • 고미아;이지아
    • 성인간호학회지
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    • 제24권4호
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    • pp.417-427
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    • 2012
  • Purpose: The purpose of this study was to examine the effect of balance taping therapy on neck pain in high school students. Methods: The study employed a randomized control group pretest-posttest design with four-time repeated measures. Data were collected from 62 high school students with neck pain. The experimental group (n=31) took balance taping therapy for six days with appropriate position and stretching education while the control group (n=31) applied patches including non-steroidal anti-inflammatory drugs (NSAIDS) for six days with appropriate position and stretching education. Neck pain, cervical range of motion (CROM) and neck disability were measured at pretest, day one, day three and day six which was the posttest day. Results: For the experimental group, the neck pain was significantly improved on all three days (F=16.82, p<.001), and extension and right lateral flexion of the CROMs were significantly improved over time compared to the control group (F=3.85, p =.011; F=2.71, p=.047, respectively). Neck disability was also improved in the experimental group compared to the control group (F=8.64, p<.001). Conclusion: The balance taping therapy was an efficient intervention for high school students with neck pain. Nurses could apply non-pharmacological interventions such as balance taping therapy without pharmacological side effects.

Pedicled Perforator Flaps for Reconstruction of Bilateral Knee Defects: A Case Report

  • Park, Joo Seok;Hong, Joon Pio;Oh, Tae Suk
    • Archives of Reconstructive Microsurgery
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    • 제23권2호
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    • pp.101-104
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    • 2014
  • Reconstruction of soft tissue defects of the knee has always been a challenging task for plastic surgeons. Various reconstructive choices are available depending on the location, size, and depth of the defect relative to the knee joint. Defects on the knee joint have several characteristic features. The use of a free flap is preferred for reconstructions involving obliteration of large-cavity defects, but recipient pedicle isolation can be difficult because of the extent of the injury zone. Furthermore, the true defect during knee joint flexion is larger than during knee joint extension, and a durable flap is necessary for joint movement. We report for the first time on the use of pedicled perforator flaps for reconstruction of bilateral knee defects in a 76-year-old woman. The operative procedure required skeletonizing the perforators of an antero-lateral thigh flap and antero-medial thigh flap and rotating the flap in the defect. The patient returned to normal daily activity and had a full range of motion two months after the accident. The shorter operating time with decreased donor site morbidity and its durability make this flap a valuable alternative for soft tissue reconstruction of the knee.

간헐적 견인과 도수 견인이 요추 추간판 탈출에 미치는 효과 (The Effects of Intermittent Traction and Manual Traction on Lumbar Herniated Disc)

  • 권원안;마상렬;황윤태
    • The Journal of Korean Physical Therapy
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    • 제21권3호
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    • pp.9-16
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    • 2009
  • Purpose: The purpose of this study was to investigate the effects of intermittent lumbar traction and manual traction on a $L_{4-5}$ herniated disc. Method: The subjects were randomly divided into the intermittent lumbar traction group (n=10) and the manual traction group (n=10). The intermittent traction group had traction-treatment applied for 12 times in the first two weeks, and then 6 times in the next two weeks. The time the traction was applied was for 30 minutes. The manual traction group had flexion-distraction therapy applied for 12 times in first two weeks, and for 6 times in next two weeks. The time the traction was applied was 3 to 6 minutes per treatment. Results: The change of the muscle test (MT), the disc herniation index (DHI) and the sagittal $T_2$ weighted MRI was measured at pretreatment and 4weeks and 12weeks after treatment. Conclusion: We found that intermittent lumbar traction and manual traction could improved the MT and DHI and this could improve the rehabilitation of patients with lumbar herniated disc.

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저출력 레이저의 치료 효과 규명을 위한 근전도 신호의 피로도 해석 연구 (Muscle Fatigue Analysis Based on Electromyography Signals for The Evaluation of Low-Level Laser Therapy)

  • 김지현;최효훈;윤종인
    • 대한의용생체공학회:의공학회지
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    • 제32권4호
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    • pp.319-327
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    • 2011
  • Skeletal muscle fatigue is defined as a 'any reduction in the maximal capacity to generate force or power output', and is the reduction of oxygen consumption and by-product of metabolism. For the muscle fatigue therapy, low level laser has been introduced that leads the mitochondrial respiratory and attributes the muscle fatigue recovery. This study analyzed the muscle fatigue signals from electromyography(EMG) during low-level laser therapy (LLLT). Healthy subjects performed voluntary elbow flexion-extension excercise and received placebo LLLT and active LLLT using a 830 nm laser diode. Then, EMG were measured for the evaluation of muscle fatigue. The acquired EMG data were analyzed with median frequency and short time fourier transform methods. The results showed that the LLLT had a significant symptomatic relief of muscle fatigue based on the EMG frequency analysis. Therefore, the muscle fatigue analysis with EMG signals can be applied to quantitative evaluation for the monitoring of LLLT effects.

국가대표 크로스컨트리 스키 선수들의 Start & Finish 구간에 대한 Double poling 기술의 운동학적 분석 (The Kinematic Analysis about Double Poling Technique of National Cross-Country Skiers at Start & Finish Phases)

  • 최슬비;류재균
    • 한국운동역학회지
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    • 제22권1호
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    • pp.95-104
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    • 2012
  • The purpose of this study targeted to national cross-country skiers representatives was to implement hypothetical experiment on their patterns of the movements and analysis on kinematic variables occurred while double polling was conducted between starting and finishing phase of 56 meters. Furthermore, it aimed to provide a set of quantitative data to illustrate how to improve one's skill and performance of sprint. In our experiments, we conducted 3-dimension analysis of cycle characteristics, joint angle(hip, knee and elbow), and pole angle. The results showed that at the starting phase, the players did not show a significant difference in attributes of time and distance. In heat 1 where elbow angle and polling starts, the pole angle was noticeably high in heat 1. At the finishing phase, there was a considerable distinction with a high frequency in performing a short polling time and high speed in heat 3. The players showed large extension between the flexion and of the hip angle which indicates high contribution given from the movement of lower body(hip, knee).

The Relationship among Stride Parameters, Joint Angles, and Trajectories of the Body Parts during High-Heeled Walking of Woman

  • Park, Sumin;Lee, Minho;Park, Jaeheung
    • 대한인간공학회지
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    • 제32권3호
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    • pp.245-252
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    • 2013
  • Objective: This paper analyzes the changes on stride parameters, joint angles, and trajectories of the body parts due to high heels during walking and explains the causal relationship between the changes and high heels. Background: This study aims to indicate the comprehensive gait changes by high heels on the whole body for women wearing high heels and researchers interested in high-heeled walking. Method: The experiment was designed in which two different shoe heel heights were used for walking (1cm, 9.8cm), and twelve women participated in the test. In the experiment, 35 points on the body were tracked to extract the stride parameters, joint angles, and trajectories of the body parts. Results: Double support time increased, but stride length decreased in high-heeled walking. The knee inflexed more at stance phase and the spine rotation became more severe. The trajectories of the pelvis, the trunk and the head presented outstanding fluctuations in the vertical direction. Conclusion: The double support time and the spine rotation were changed to compensate instability by high heels. Reduced range of motion of the ankle joint influenced on the stride length, the knee flexion, and fluctuations of the body parts. Application: This study can provide an insight of the gait changes by high heels through the entire body.

노르딕 워킹과 일반 보행의 효율성 비교 분석 (Comparative Analysis of Nordic Walking and Normal Gait Based on Efficiency)

  • 김로빈;조준행
    • 한국운동역학회지
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    • 제20권4호
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    • pp.365-372
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    • 2010
  • The purpose of this study were to analyze the changes in kinematic and kinetic parameters and to find biomechanical benefits of Nordic Walking and normal gait performed under the same velocity. Nine participants(age: $26.73{\pm}3.28$ year, height: $182.45{\pm}4.62\;cm$, weight: $76.59{\pm}6.84\;kg$) was chosen. The velocity of gait was set by 5.75 km/h which was made by a Nordic Walking professional. The data were collected by using VICON with 8 cameras to analyze kinematic variables with 200 Hz and force platform to analyze kinetic variables with 2000 Hz. The results of this study were as follows. First, when compared with Normal gait, Nordic Walking group showed decreased Plantarflexion angle and ROM. Second, Nordic Walking group showed decreased knee flexion angle and ROM. Third, Nordic Walking group showed increased hip joint movement. Fourth, Nordic Walking group showed higher active GRF but decreased loading rate from delayed Peak Vertical GRF time and increased impulse. Fifth, Nordic Walking group showed longer ground contact time. Through this study, we found that Nordic Walking showed higher stability and efficiency during gait than normal gait and that Nordic Walking may help people who have walking difficulties.

Sex Differences in Hamstring Flexibility Changes After Specific Warm-up

  • Wootaek Lim
    • 한국전문물리치료학회지
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    • 제30권4호
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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 5th trial compared with the 1st 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.

대학 골프 선수의 Pitching wedge 스윙동작의 운동학적 특성 분석 (Kinematical Analysis of Pitching wedge swing motion in University Golfer)

  • 백진호;윤동섭;김재필
    • 한국운동역학회지
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    • 제13권3호
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    • pp.133-149
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    • 2003
  • The purposes of present study were to determine the major check-points of golf swing from the review of previous studies, and to suggest additional information on the teaching theory of golf. The golf swing motion of 6 male and female elite university golf players were filmed with 16mm Locam II high speed cameras at the speed of 200f/s, and variables such as time, displacement, angle, velocity were calculated and analyzed by 3D Cinematography using DLT method. The results were: 1. Differences were shown in the ratio of weight distribution on the feet, cocking angle, take-back velocity, club-head velocity at impact depending upon the physical characteristics and club used for swing. 2. Time for the down-swing and impact were $0.27{\sim}0.29s$ in men and $0.29{\sim}0.32s$ in women, which was 1/3 of the time for the back-swing. Women showed longer total swing time than men because of longer time in back-swing, follow-through and finish. 3. Men showed larger range of motion in shoulder and knee joints than women, on the other hand women showed larger range of motion in hip joint than men. 4. Cocking motion and right elbow flexion were occurred at the top of back-swing and cocking release was occurred at the moment of impact. Maximum rotations of shoulder and hip joints were found between the top of back-swing and down-swing phase. 5. Women showed lower back-swing velocity than men, and men showed higher club velocity(men: $38.2{\sim}38.6m/s$, women: $35.1{\sim}36.4m/s$) than women.