• Title/Summary/Keyword: Force reproduction sense

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Influence of Muscle Fatigue on the Sensing of Force Reproduction in Elbow Flexors (주관절 굴곡근의 근피로가 힘 재현 감각에 미치는 영향)

  • Lee, Won-Hwee;Ha, Sung-Min;Kim, Yong-Wook;Oh, Jae-Seop
    • Physical Therapy Korea
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    • v.14 no.3
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    • pp.16-22
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    • 2007
  • The purpose of this study was to determine the influence of muscle fatigue in elbow flexors on the sense of force reproduction. Fifteen healthy subjects were recruited for this study. Maximum voluntary force (MVF) of elbow flexor muscles was measured by a digital tensiometer. Force errors were measured to test accuracy of the sense of force reproduction in elbow flexors. The subject was required to flex the elbow joint, to maintain and concentrate on about 20% of the MVF target force under visual feedback for 3 seconds. After a 5 second period rest, the subject was asked to duplicate the target force actively. Muscle fatigue was evoked with isometric contraction of the elbow flexors. Isometric contraction was continued until a 50% drop in MVF. The difference, in kilogram between the target force and the reproduced force was calculated for measuring force error. Force errors were compared between the non-fatigued condition and the fatigued condition by the paired t-test. Force errors were significantly increased in the fatigued condition compare to non-fatigued condition. This result suggests that the sense of force reproduction can be disturbed by localized muscle fatigue.

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Effect of Muscle Fatigue on the Proprioception by the Taekwondo Training Type

  • Seo, Byoung-Do;Kim, Hui-Jae;Ju, Joung-Youl
    • Journal of the Korean Society of Physical Medicine
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    • v.15 no.3
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    • pp.1-9
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    • 2020
  • PURPOSE: This study examined the effects of muscle fatigue on proprioception in the type of taekwondo training, causing injury to taekwondo athletes. METHODS: The subjects were divided into Taekwondo Kyorugi athletes (n = 14) and Taekwondo Poomsae athletes (n = 14). After inducing muscle fatigue to the subjects, the joint position sense (JPS) and the force reproduction sense (FRS) were measured before and immediately after the induction of muscle fatigue. RESULTS: Studies have shown no significant impact on the JPS and FRS caused by muscle fatigue induced by Poomsae and Kyorugi (p > .05). The JPS, however, showed a significant difference before and after Kyorugi (p < .05). The FRS showed significant differences before and after Poomsae (p < .05). Through this study, the injuries to taekwondo athletes appear to be influenced by the joint position and force reproduction. Moreover, the injury appears to affect the joint position sense in Kyorugi athletes and the force reproduction sense in Poomsae athletes. CONCLUSION: The results will contribute to injury prevention and athlete protection. In addition, the information can be used as basic data for the development of sports injuries prevention and rehabilitation programs for Taekwondo athletes. Research is needed on the customized management of sports methods and self-care to prevent sports damage, considering the athletic characteristics of the taekwondo athletes in the future.

Reproduction of Arm Kinesthetic Sense in Virtual Environment Using Bilateral Control (양방향 제어를 이용한 가상환경에서의 팔운동감 제시)

  • 정웅철;민두기;송재복;김용일
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 1999.11a
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    • pp.97-100
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    • 1999
  • Human feels kinesthetic sense in response to the force acted on him. In order to represent kinesthetic sense, a force is analyzed as mechanical impedance (i.e., stiffness or damping) and implemented by active impedance control. In this research, a 3-dimensional arm motion generator is developed to present various mechanical impedance characteristics to an operator. An introduction of virtual reality provides not only a visual effect in virtual environment but also the change in force synchronized with the visual effect in real time.

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The Effect of Graded Exercise-Induced Fatigue on Position Sense of the Knee (근피로를 유발하는 운동강도 변화가 슬관절의 위치감각 인지에 미치는 영향)

  • Yi, Chung-Hwi;Choi, Jong-Duk;Lee, Kang-Noh;Lee, Dong-Ryul;Choi, Jae-Myung
    • Physical Therapy Korea
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    • v.6 no.3
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    • pp.22-37
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    • 1999
  • It was recently reported that exercise-induced fatigue is related to joint position sense although some controversy remains. The purposes of this study were to examine the effect on the accuracy of reproducing the knee angles after a fatiguing isokinetic quadriceps exercise at four different levels (10%, 30%, 50%, and 70% of maximal force) and to find the optimal exercise level without causing knee joint proprioception impairment. Forty healthy women, ages 19 to 27, were randomly assigned to four experimental groups. Before and after the exercise, accuracy of positioning with respect to auditory feedback for specific angles was estimated by calculating the mean errors between specific angles and reproduction angles. Fatigue was measured by EMG signals displayed by a frequency spectrum analysis during the quadriceps exercise. Results showed that there was no significant difference in accuracy of the knee joint positioning sense following the exercises in group 1, group 2, and group 3 (10%, 30%, and 50% of maximal force, respectively); the exception being group 4 (70%). Fatigue level was significantly increased in group 4 but there were no significant increases of fatigue level in group 1, group 2, or group 3. The results concluded that the optimal exercise level to acquire the therapeutic exercise effectiveness without position sense impairment was at 50% of maximal force. Further studies using large sample size and patient groups with poor knee joint proprioception would be needed to confirm this conclusion and to clarify the possibility of clinical applications.

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The Education of Henry Adams: The Theme of Aura and Tradition in the Context of Modernity

  • Kim, Hongki
    • Journal of English Language & Literature
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    • v.55 no.6
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    • pp.961-973
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    • 2009
  • Walter Benjamin expresses his concern that the new technologies of mechanical reproduction robs the artwork of its own uniqueness, its "aura." Benjamin uses the word "aura" to refer to the sense of awe or reverence one presumably experiences in the presence of works of art. This aura does not merely inhere in the works of art themselves, because Benjamin extends his notion of aura to the level of how he both understands and positions the modern subject in the world of uncertainty and transitoriness. The theoretical framework of Benjaminian aura becomes a crucial and efficient strategic apparatus to read The Education of Henry Adams. As for Benjamin the modern implies a sense of alienation, a historical discontinuity, and a decisive break with tradition, Adams observes that modern civilization has wiped out "tradition," a mythic home in which man can experience order and unity. Adams claims that the growth of science, reason, and multiplicity at the expense of religion, feeling, and unity has been accompanied by a parallel growth in individualism at the expense of community and tradition. To Adams the collapse of traditional values such as maternity, fecundity, and security in America is a waking nightmare of the moral dilemmas of a capitalist society, in which the cruel force of the modern Dynamo is becoming a prime governing principle.

Revisiting Transnational American Studies: Race and the Whale in Melville's Moby-Dick

  • Kang, Yeonhaun
    • Journal of English Language & Literature
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    • v.64 no.4
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    • pp.585-600
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    • 2018
  • Over the last three decades, the field of American Studies has increasingly paid attention to transnational approaches in an effort to diversify and expand the field's concerns beyond the narrow sense of the nation-state in today's globalizing world. Yet, the mediation of the transnational requires a careful analysis of the nation that is still in transit. In this context, this essay examines Herman Melville's novel Moby-Dick (1851) as a case study that vividly shows how reading American literature and culture through transnationalism not only offers new interpretations of canonical texts, but also helps us to better understand the historical roots and cultural contexts of contemporary issues such as global labor and migration, US citizenship and racial justice. To address the complexity of the text's circulation and reproduction, coupled with US national ideology and cultural conditions, I first turn to the canonization of Melville's Moby-Dick during the Cold War era as a national project and then explore the possibilities of transnational readings by focusing on the politics of race and global capitalism in the nineteenth century whaling industry. In doing so, I argue that critical transnationalism allows readers to keep questioning about their own understanding of race, nation, and cultural identity while remaining attentive to the destructive force of US imperialism and global capitalism in the twenty-first century.