• 제목/요약/키워드: Voluntary Activity

검색결과 351건 처리시간 0.023초

노화가 지속적 최대하강도 수축시 근피로 기전에 미치는 영향 (The Effect of Aging on the Mechanism of Muscle Fatigue during Sustained Submaximal Isometric Contraction)

  • 윤태진;김용운;정철수
    • 한국운동역학회지
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    • 제15권3호
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    • pp.51-59
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    • 2005
  • To examine the influence of aging on the mechanism of muscle fatigue, we compared the magnitude of central and peripheral fatigue in young and old women before, during and after a sustained submaximaI isometric contraction of elbow flexor muscles. Twelve women (6 young. $20.7{\pm}1.2$ years and 6 old, $68.8{\pm}29$ years) performed a contraction at 20% of maximal voluntary contraction (MVC) torque with their non-dominant arm. The old women were weaker than the young women, however their endurance time for the 20% contraction was longer compared with the young women ($1822{\pm}444$ vs. $1061{\pm}678$ sec, P <. 05). Both groups had a similar reduction in voluntary activation ratio (VA) during and after the fatiguing contraction. However, the old women showed much greater variability in VA before and after the contraction ($91.61{\pm}4.54%$ and $76.70{\pm}19.55\;%$ range of $79{\sim}99$ to $87{\sim}99%$ respectively) compared with the young women ($95.71{\pm}1.86\;%$ and $83.46{\pm}7.57\;%$ range of $39{\sim}75$ to $69{\sim}90%$, respectively). Furthermore, the EMG activity of the elbow flexor muscles and triceps brachii was greater for the old women compared with the young women throughout the fatiguing contraction, indicating different activation strategies with age. Indices of peripheral fatigue including twitch properties, showed that fatigue within the muscle was more rapid for the young women compared with the old women. These results suggest that although old women are weaker than young women, they have greater endurance due to mechanisms within muscle. Furthermore, old women showed great variability in their ability to optimally activate all muscle fiber compared with young women for an isometric contraction.

품질분임조 활동의 진흥방향 제안에 관한 연구 (A Suggestion on the Promotive Directions of Quality Circle Activity)

  • 이강인;김현
    • 품질경영학회지
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    • 제35권2호
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    • pp.1-26
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    • 2007
  • The purpose of this research is to suggest the promotive directions of Quality Circle activity. Since 1975, variety of organizations in Korea have widely the implemented Quality Circle activities for their management systems. Today, Companies are facing the harsh realities of a competitive environment. This is no time for revolutionary change. Instead, Companies are instituting revolutionary change meant to have impact within a very short time frame. The Worker's Quality Circle activity is, essentially, a trouble shooting oriented voluntary small group within their working place to improve the surroundings creatively. The industries have enthusiastically used Quality Circle activities and were influenced from them. The Quality Circle activities can be regarded as a kind of Knowledge Management where new knowledge is created and knowledge is shared in the economy. However, the academics were less interested in this subject, as a result, there were no systematic guidances for Quality Circle activities. Also, the government was less interested in these activities, as a result, there were no systematic policy making for Quality Circle activities. Thus, in this research, the promotive directions for Quality Circle activities were suggested which were based on the results of survey Questionnaires presented to promoters of the domestic companies. As a results of this research, to maximize the effect of TQM(Total Quality Management) in the nationwide, Quality Circle activity as a bottom-up management should be more expanded and revitalized.

발목 관절 염좌 후 하퇴근 근활성도의 특성 (Electromyography Activity of Lower Leg Muscles After Ankle Sprain)

  • 하성희;이현옥;김선엽;김종순
    • The Journal of Korean Physical Therapy
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    • 제17권4호
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    • pp.621-631
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    • 2005
  • The purpose of this study was to measure magnitude of lower leg muscle activity during dynamic stability tests performed on an unstable board by subjects with sprained lateral ankles. Fifteen lateral ankle sprain subjects(8 male, 7 female) participated in this study. The muscle activity was measured at gastrocnemious, tibialis anterior, peroneus longus during dynamic stability tests performed on Biodex stability system as surface EMG. The EMG amplitude of each muscle was normalized to the amplitude in the maximal voluntary isometric contraction(MVIC) of each muscle. As results, peroneus longus evidenced significant difference at stable and unstable grade comparing injured with uninjured sides. Gastrocnemious and tibialis anterior evidenced no significant difference. Change of muscle activity with stable and unstable grade evidenced no significant difference on injured and uninjured sides. The data provided information on peroneus longus contributes to dynamic stability after lateral ankle sprains. Peroneus longus training program may have to be emphasized after an ankle sprain.

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Eletromyographic Activities of Trunk and Lower Extremity Muscles During Bridging Exercise in Whole Body Vibration and Swiss Ball Condition in Elderly Women

  • Kim, Tack-Hoon;Lee, Kang-Seong
    • 한국전문물리치료학회지
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    • 제17권4호
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    • pp.26-34
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    • 2010
  • The purpose of this study was to compare the trunk and lower extremity muscle activity induced by six different conditions floor, intensity 0, 1, 3, 5 of whole body vibration (WBV), and Swiss ball during bridging exercise. Surface electromyography (EMG) was used to measure trunk and lower extremity muscles activity. Ten elderly women were recruited from Hong-sung Senior Citizen Welfare Center. The collected EMG data were normalized using reference contraction (during floor bridging) and expressed as a percentage of reference voluntary contraction (%RVC). To analyze the differences in EMG data, the repeated one-way analysis of variance was used. A Bonferroni's correction was used for multiple comparisons. The study showed that EMG activity of the rectus abdominis, external oblique, internal oblique, erector spinae and rectus abdominis muscles were not significantly different between six different conditions of during bridging exercise (p>.05). However, there were significantly increased EMG activity of the rectus femoris (p=.034) in the WBV intensity 0, 1, 3, and 5 conditions compared with the floor bridging condition. EMG activity of the medial gastrocnemius were significantly increased in the WBV intensity 0, 1, 3, 5 and Swiss ball conditions compared with the floor bridging condition. Future studies are required the dynamic instability condition such as one leg lifting in bridging.

무용 활동 프로그램을 통한 초등학생의 신체활동과 정서인식 변화 연구 (Dance activity program for elementary school students through a program of physical activity and emotional change research)

  • 김미주
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2013년도 춘계 종합학술대회 논문집
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    • pp.321-322
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    • 2013
  • 본 연구는 초등학생의 개인적인 특성을 고려하여 무용 움직임과 연극적인 표현을 융합시킨 프로그램을 구성하였고 무용 활동을 적용하여 프로그램모형을 제시함으로서 누구나 쉽게 무용을 체험 할 수 있도록 시도하였다. 특히 초등학생들에게 프로그램을 적용함으로서 나타날 수 있는 신체활동과 정서인식 변화에 중점을 두어 적용한 결과, 참여자들은 무용 활동 프로그램을 통해 신체움직임 표현의 상호인식에 따른 소통방법과 신체를 통한 다양한 표현방법으로 의미전달을 할 수 있었으며, 긍정적인 사고, 자발적인 참여 및 대인관계 형성을 갖게 되었으며 신체 활동과 의식변화에 대한 자긍심과 자신감을 갖게 되었다.

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발가락 감기 운동 시 지절관절 자세에 따른 무지외전근의 근 활성도 비교 (Comparison of Abductor Hallucis Muscle Activity During Toe Curl Exercises According to the Position of the Interphalangeal Joint)

  • 정도영;고은경
    • 한국전문물리치료학회지
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    • 제16권2호
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    • pp.9-15
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    • 2009
  • The purposes of this study were to compare abductor hallucis (AbdH) muscle activity during toe curl exercise according to position of interphalangeal joint (IPJ). Fifteen healthy subjects with neutral foot were recruit for this study. All subjects performed toe curl exercise with towel while maintaining the IPJ in flexion (condition 1) and extension (condition 2). Toe curl exercise with towel was perform three trials for five second periods in each condition. Surface electromyography (EMG) activities were recorded from three muscles (AbdH, tibialis anterior, peroneous longus) in each condition. EMG activity was normalized to the value of maximal voluntary isometric contraction (%MVIC). The EMG activities acoording to position of IPJ were compared using a paired t-test. This study showed that the EMG activity of AbdH during toe curl exercise with IPJ extension significantly increased compared to those during toe curl exercise with IPJ flexion (p<.05). However, the EMG activity of tibialis anterior and peroneus longus were not significantly different between the conditions (p>.05). These results suggest that toe curl exercise with towel must be performed with extension of IPJ in order to strengthen intrinsic muscle in subjects with overuse injuries related to excessive pronation.

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Effects of Seated Exercise of Thoracic and Abdominal Muscles on Upper Extremity Function and Trunk Muscles Activity in Patients with Chronic Stroke

  • Park, Shinjun;Kim, Sangduk
    • 국제물리치료학회지
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    • 제11권2호
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    • pp.2065-2070
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    • 2020
  • Background: Weakness of the abdominal and mid thoracic muscles the lead to thoracic kyphosis of stroke patients. The trunk muscles activity of stroke patients is significantly related to upper extremity. Objectives: To investigate the effect of seated exercise of thoracic and abdominal muscles on upper extremity function and trunk muscles activity in stroke patients. Design: One-group pretest-posttest design. Methods: A total of 27 stroke patients were recruited. All stroke patient were given seated abdominal exercise (posterior pelvic tilt exercises) and thoracic exercise (postural-correction exercise). All exercises were conducted for 30 minutes, three times a week for four weeks. The manual function test (MFT) and electromyography (EMG) were measured, and EMG electrodes were attached to thoracic paraspinal muscles and lower rectus abdominal muscles. EMG signal is expressed as %RVC (reference voluntary contraction). Results: Experimental group showed significant increases in abdominal muscles, paraspinal muscles activity and MFT total score, items of arm motion (forward elevation of the upper extremity, lateral elevation of the upper extremity, touch the occiput with the palm) in MFT after four weeks. Conclusion: These results suggest that, in stroke patients, seated exercise of thoracic and abdominal muscles contribute to improve trunk muscles activity and upper extremity function in stroke patients.

요부안정화 운동이 만성요통여성 환자의 근활성도와 등속성 근력에 미치는 영향 (The Effects of Lumbar Stabilization Exercise on Muscle Activity and Isokinetic Muscle Strength of Female Patients with Chronic Low Back Pain)

  • 방현수
    • 대한물리의학회지
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    • 제10권2호
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    • pp.63-71
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    • 2015
  • PURPOSE: The purpose of this study to investigate the effects of exercise on lumbar stabilization in muscle activity and isokinetic muscle strength of female with chronic low back pain. METHODS: The candidates was chose to twenty women in their 30s and 40s complaining back pain for over 12 weeks and consist of 10 people for lumbar stabilization and general physical therapy group(PL group), another 10 people for general physical therapy group(GP group). Lumbar stabilization exercise was conducted for 8 weeks and was comprised of 60 minutes for two times a week. In order to examine the effects of lumbar stabilization, results in the present study were analyzed maximal voluntary isometric contraction (MVIC) using electromyogram to measure muscle activity and isokinetic performance including peak torque and average power at the pre to post. RESULTS: The following are results in this study. The MVIC and isokinetic muscle strength were gradually increased in all group. As the result of the test of the MVIC and isokinetic muscle strength, the difference of lumbar stabilization and general physical therapy group is statistically more significant than that of general physical therapy group. CONCLUSION: In the present study, results indicate that lumbar stabilization helps to improve the muscle activity and isokinetic muscle strength.

Effect of Backward Versus Forward Lunge Exercises on Trunk Muscle Activities in Healthy Participants

  • Song, Jae-Keun;Yoo, Won-Gyu
    • 한국전문물리치료학회지
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    • 제28권4호
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    • pp.273-279
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    • 2021
  • Background: Lunge exercises are lower extremity rehabilitation and strengthening exercises for patients and athletes. Most studies have shown the effectiveness of the forward and backward lunge exercises for treating patellofemoral pain and anterior cruciate ligament injuries (by increasing lower extremity muscle activity) and improving kinematics. Objects: However, it is not known how the two different lunge movements affect trunk muscle activities in healthy individuals. The purpose of this study was to investigate the electromyographic activity of the rectus abdominis and erector spinae muscles during forward and backward lunge exercises in healthy participants. Methods: Twelve healthy participants were recruited. Electromyographic activity of the rectus abdominis and erector spinae was recorded using surface electrodes during forward and backward lunges, and subsequently normalized to the respective reference voluntary isometric contractions of each muscle. Results: Activity of the erector spinae was significantly higher than that of the rectus abdominis during all stages of the backward lunge (p < 0.05). The activity of the erector spinae was significantly greater during the backward than forward lunge at all stages (p < 0.05). Conclusion: Backward lunging is better able to enhance trunk motor control and activate the erector spinae muscles.

Functional Amino Acids and Fatty Acids for Enhancing Production Performance of Sows and Piglets

  • Kim, Sung Woo;Mateo, Ronald D.;Yin, Yu-Long;Wu, Guoyao
    • Asian-Australasian Journal of Animal Sciences
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    • 제20권2호
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    • pp.295-306
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    • 2007
  • The growth and health of the fetus and neonate are directly influenced by the nutritional and physiological status of sows. Sows are often under catabolic conditions due to restrict feeding program during pregnancy and low voluntary feed intake during lactation. The current restrict feeding program, which aims at controlling energy intake during gestation, results in an inadequate supply of dietary protein for fetal and mammary gland growth. Low voluntary feed intake during lactation also causes massive maternal tissue mobilization. Provision of amino acids and fatty acids with specific functions may enhance the performance of pregnant and lactating sows by modulating key metabolic pathways. These nutrients include arginine, branched-chain amino acids, glutamine, tryptophan, proline, conjugated linoleic acids, docosahexaenoic acid, and eicosapentaenoic acid, which can enhance conception rates, embryogenesis, blood flow, antioxidant activity, appetite, translation initiation for protein synthesis, immune cell proliferation, and intestinal development. The outcome is to improve sow reproductive performance as well as fetal and neonatal growth and health. Dietary supplementation with functional amino acids and fatty acids holds great promise in optimizing nutrition, health, and production performance of sows and piglets. (Supported by funds from Texas Tech, USDA, NLRI-RDA-Korea, and China NSF).