• Title/Summary/Keyword: Time Extension

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The Effects of Hip Extension Velocity on the Relative Onset Time of the Gluteus Maximus in Relation to the Hamstring (고관절 신전속도가 슬괵근에 대한 대둔근의 상대적 근수축 개시시간에 미치는 영향)

  • Chang, Young-Jin;Ko, Eun-Hye;Roh, Jung-Suk;Cynn, Heon-Seock;Kim, Tack-Hoon
    • Physical Therapy Korea
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    • v.13 no.2
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    • pp.70-76
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    • 2006
  • The purpose of this study was to investigate the effects of hip extension velocity (7.5 degree/second, 30 degree/second) on the relative onset time of the gluteus maximus in relation to the hamstring during hip extension in prone position. Thirteen healthy male subjects (mean age=22.6 years [SD=1.8], mean weight=73.4 kg [SD=10.3], mean height=176.1 cm [SD=6.3]) voluntarily participated in this study. Electromyographic data was collected on the gluteus maximus and hamstring to determine onset time. Statistical analyses were performed with the paired t-test. The results showed that the onset time of the hamstring was significantly faster than that of the gluteus maximus in both fast and slow hip extension velocity. The gluteus maximus began contraction .079 seconds later following the contraction of the hamstring. The onset time of the hamstring was significantly faster in fast hip extension velocity compared with slow hip extension velocity. In conclusion, it was determined that the onset time of the gluteus maximus was faster with fast hip extension velocity compared with slow hip extension velocity. There was a statistically significant difference between the onset times of the gluteus maximus and hamstring in relation to the two velocities (p<.05). Further study is needed to examine whether the velocity of hip extension can influence the onset time in a similar fashion in patients with low back pain.

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Improvement of Apportioning Responsibility for the Time Extension in Construction Projects (건설공사 공기연장 책임구분의 문제점 및 개선방안 제시)

  • Kim, Jong-Han;Kim, Kyung-Rai
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2007.11a
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    • pp.60-67
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    • 2007
  • Cases of the time extension have continuously transpired in the public construction projects. The potential of economical loss and claims is increased because the concerned parties such as an owner or a contractor have not properly performed their own responsibility for the time extension. Therefore, this paper aimed to improvement of apportioning responsibility for the time extension in construction projects.

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The Effect of Different Elastic Tape Expansibilities on the Onset Time of Muscle Contraction during Neck Extension for Forward Head Posture Syndrome (목 폄 시 탄력성 테이프의 신장력 차이가 전방머리자세 증후군의 근수축 개시시간에 미치는 영향)

  • Yoon, Jung-Gyu
    • PNF and Movement
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    • v.20 no.3
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    • pp.331-340
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    • 2022
  • Purpose: Thisstudy aimed to identify the effect of varying the expansibility of elastic tape on the onset time of muscle contraction during neck extension for forward head posture syndrome. Methods: Forty-five young adults with forward head posture syndrome volunteered to participate and were randomly assigned to one of three groups according to the expansibility of the elastic tape (25%, 50%, 75%). The onset time of muscle contraction for the neck extensor during neck extension was measured using an electromyographic system (Free EMG, BTS, Italy). Multivariate analysis of variance was employed to determine the effect of different expansibilities of elastic tape on the onset time of muscle contraction during neck extension for forward head posture syndrome. When there was a statistically significant difference by MANOVA, Scheffe was used as a post-hoc test. The level of significance was set at α=0.05. Results: In the comparison of the onset time of muscle contraction of varying elastic tape expansibilities and measurement times, there was a significant difference between the groups (Lt. UT, Lt. SCM, Rt. SCM) (p < 0.05), but there was no significant difference in the interaction between the measurement time and the group, between the measurement time (p > 0.05). Conclusion: In the neck extension, 75% of the tape extensibility in the Lt. UT and both SCM shortened the muscle contraction onset time.

Activation and Onset Time of the Gluteus Maximus Muscle during Three Different Prone Table Hip Extension Exercises

  • Jeon, In-Cheol
    • The Journal of Korean Physical Therapy
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    • v.32 no.5
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    • pp.295-301
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    • 2020
  • Purpose: The purpose of this study was to compare the electromyographic activity and onset time of the gluteus maximus (GM) and hamstring (HAM), lumbopelvic kinematics during three different prone table hip extension exercises in healthy individuals. Methods: Twenty subjects were participated. Electromyography device was used to measure the muscle activities and onset time of the GM and HAM muscles. An electromagnetic tracking motion device was used to measure lumbopelvic compensations. The subjects were asked to perform three different prone table hip extension [Prone table hip extension with the abdominal drawing-in maneuver on a chair (PTHEA), PTHEA with the ipsilateral knee flexion (PTHEAF), PTHEAF with hip 30 abduction (PTHEAFA)]. One-way repeated measures analysis of the variance and a Bonferroni post hoc test were used. Results: The electromyographic activity and onset time were significantly different among three conditions (PTHEA vs. PTHEAF vs. PTHEAFA)(p<0.01). The GM muscle activity and onset time were significantly greater and reduced during the PTHEAFA compared to PTHEA and PTHEAF (p<0.01). However, The HAM muscle activity and onset time were significantly smaller and delayed during the PTHEAFA compared to PTHEA and PTHEAF (p<0.01). Conclusions: PTHEAFA exercise can be recommended to facilitate the muscle activity and efficient muscle firing time of GM without HAM dominance.

The Effects of Hamstring Length on the Static Stance Balance Ability (슬괵근 길이가 정적 기립균형 능력에 미치는 영향)

  • Nam, Kun-Woo;Park, Dae-Sung
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.13 no.2
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    • pp.45-54
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    • 2007
  • The purpose of this study was effect of hamstring length on one leg stance test(OLST) in 108 persons. (men 28, women 80). The active knee extension test(AKE) was applied 3 times on both leg and high score was selected. Then, one leg stance test(OLST) was applied 3 times on both leg and high score was selected. Also, persons divided two group that is normal hamstring length group and shortening group). The result were as follows : 1. The correlation analysis between Lt. hamstring length and one leg stance time was no significant relation($p_{Lt.}=0.271$, $p_{Rt.}=0.051$). 2. The correlation analysis between Rt. hamstring length and one leg stance time was no significant relation($p_{Lt.}=0.837$, $p_{Rt.}=0.334$). 3. The independent T -test between Lt. hamstring normal (knee extension > 150degrees) & shortening group (knee extension ${\leq}$ 150 degrees) in Lt. leg stance time was no significant difference(p=0.73), but in Rt. leg stance time was statistically significant difference(p=0.04). 4. The independent T-test between Rt. hamstring normal (knee extension > 150degrees) & shortening group (knee extension ${\leq}$ 150 degrees) in one leg stance time was no significant difference($p_{Lt.}=0.09$, $p_{Rt.}=0.16$).

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The Comparison of the Onset Time of Hamstring, Gluteus Maximus, and Lumbar Erector Spinae Muscle Activity During Hip Extension Between Subjects With Low Back Pain and Healthy Subjects (고관절 신전시 요통환자와 정상인의 슬괵극, 대둔근, 요추기립근의 근 수축 개시시간 비교)

  • Kwon, Oh-Yun;Koh, Eun-Kyung
    • Physical Therapy Korea
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    • v.9 no.2
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    • pp.33-42
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    • 2002
  • The purpose of this study was to compare the onset times of muscle activities and the order of muscle firing in hamstring gluteus maximus, and lumbar erector spinae muscle during active hip extension between subjects with low back pain (LBP) and healthy subjects. Thirty subjects, 15 with LBP and 15 healthy subjects, participated in this study. Electromyographic activity was recorded during active hip extension in prone and standing position. Relative onset times of these muscle activities were determined. Similar muscle firing order in hamstring, gluteus maximus, and lumbar erector spinae muscle showed in both groups and positions. However, the onset time of gluteus maximus was significantly later in prone and standing active hip extension in subjects with LBP than in healthy subjects. The onset time of lumber erector spinae muscle activity was significantly delayed in subjects with LBP in standing active hip extension, The delayed onset times of gluteus maximus and lumbar erector spinae muscles' activities were probably related to LBP. Further studies are needed to identify whether the delayed onset times of gluteus maximus and lumbar erector spinae muscle activities are the contributing factors to LBP.

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Quality Characteristics of Fresh Gastrodia elata according to Different Steaming Time (증자시간에 따른 생천마의 품질특성 변화)

  • Young Eun Song;Eun Ju Kim;Hyun Ah Han;Song Yee Lee;Chang Su Kim;Min Sil Ahn
    • The Korean Journal of Food And Nutrition
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    • v.37 no.1
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    • pp.40-47
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    • 2024
  • Gastrodia elata has been used in traditional Chinese medicine for treating headaches, dizziness, and convulsive illness for centuries. G. elata has traditionally been processed by steaming or blanching to increase the content and quality of its main ingredients. This study aimed to identify changes in physicochemical properties and active ingredients of G. elata depending on the steaming time. Data of this study could be used to develop traditional medicine and health foods. No steaming was used as a control. Steaming time was 5, 10, 20, 30, 60, or 120 min. The drying yield according to the steaming time ranged from 20.2% to 22.9%, with the lowest drying yield at 120 min. As the steaming time increased, gastrodin content increased more than that in fresh G. elatadue to inhibition of β-glucosidase enzyme activity, 4-hydroxybenzyl alcohol condensation, and parishin decomposition. Steamed G. elatadid not show higher total polyphenols, total flavonoids, or ABTS radical scavenging activities than fresh G. elata even with an increase of steaming time. The steaming time to improve the quality of G. elata may varied depending on the size of G. elata. Thus, it is important to set the steaming time taking these characteristics into consideration.

Problems in Localization of Extension Educators in Korea (농촌지도직 공무원 지방직 전환의 문제)

  • Kim, Sung-Soo
    • Journal of Agricultural Extension & Community Development
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    • v.7 no.1
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    • pp.247-254
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    • 2000
  • Since 1997, Korean government changed the status of extension educators from central government staff to county/city government staff for the sake of democratization and localization, regardless of opposition of academic society of extension professionals. Localization of extension educators followed by government restructuring in Korea, resulted various problems, such as 1) Decreased morale and number of extension educators, thus weakening the extension educational function, 2) Weakened linkages between national and local extension offices, 3) Less opportunity for in-service edition of extension educators, 4) Weakened linkages between agricultural research and extension, etc. During the last 30 years, extension services have helped Korean farmers in achieving self sufficiency of rice and year around supply of green vegetables by diffusion of vinyl house technology. Various problems after three years of localization of extension educators were discussed between announcer of radio KBS and a professor of extension in an interview format, and it was concluded that national efforts should be needed to restore morale of extension educators to continually achieve the national goals of food production, balanced national development and preservation of environment, at the same time to meet increasing needs of farmers.

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