• Journal of the Korea Concrete Institute
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• v.20 no.6
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• pp.755-763
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• 2008

The purpose of this study is to investigate the structural performance of doubly reinforced composite beams with steel fiber concretes and steel angles. For this purpose, total 6 specimens whose variables are shear span-to-depth ratio, existence of shear reinforcement, and shear reinforcement details, are made and tested. All specimens are constructed of steel fiber concretes with specified compressive strength of 30 MPa and steel fiber volumn content of 1%. From the experimental results, structural performance of doubly reinforced composite beams are evaluated in terms of strength, stiffness, ductility, and energy absorbing capacity. For the better structural performance, it is recommended that the composite beam is designed with diagonal shear reinforcement.

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.603-610
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• 2009

The purpose of this study was to determine how spandex pants affect impact force and muscle activities in the lower extremity. Seven pairs of surface electrodes were attached to the right-hand side of the body. Paired t-test was performed to test if significant difference exist between two conditions(p< .05). The average IEMG activities in the TA, BF, and GM during the landing phase reduced significantly with spandex pants compared to regular pants. All peak IEMG activities except the RF in wearing spandex pants group were significantly greater than the corresponding values in wearing regular pants one. The greater muscle activity recorded in wearing spandex pants can be attributed to the greater motor unit recruitment needed to decelerate and stabilized their bodies. Impact force and loading rate were not significantly decreased with wearing spandex pants. Since the spandex pants used in this study were not custom-fit based on girth of each participants thigh and shank, compression and elasticity for the pants could not be optimized.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.691-698
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• 2009

The purpose of this study was to examine the effect of neuromuscular electrical stimulation(LFES) during hindlimb suspension on weight and function of rat hindlimb muscles. Sprague-Dawley rats(body weight 300-350g) were randomly assigned to five groups: a HLS(n=5) that were hindlimb suspended for 14 days, a WB(n=5) that kept as control, a ES14 that were hind limb suspended for 14days with pre-application of LFES for 14 days, ES11 that were hindlimb suspended for 14 days with pre-application of LFES for 11 days, a LFES 7 that were hindlimb suspended for 14 days with pre-application of LFES for 7 days. Gastrocnemius muscle weight, stride length were significantly decreased and toe out angle were significantly increased in HLS and ES7 groups, whereas muscle weight, stride length, toe out angle were maintained in ES14, ES11. this indicated that LFES for 14 days, LFES for 11 days could prevent muscle atrophy and retain function.

• Proceedings of the Korea Contents Association Conference
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• 2012.05a
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• pp.407-408
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• 2012

요약은 이 연구는 다양한 식이 섭취와 일회 지구성 운동으로 야기되는 근육(백색 비복근) 내 AMP-activated protein kinase(AMPK), Extracellular signal-regulated kinase(ERK 1/2)와 p38 mitogen-activated protein kinase(MAPK)의 신호전달체계를 구명해 보고자 실시되었다. 실험에 사용된 쥐(Sprague-Dawley)는 총 160마리로 크게 일반 탄수화물 식이(CHO; 40마리), 포화지방 식이(SAFA; 40마리), 단일불포화 식이(MUFA; 40마리)와 다불포화 식이(PUFA; 40마리)로 나누어 연구를 진행하였다. 운동 프로그램은 일회 지구성 운동으로 30분 운동 후 5분 휴식의 사이클을 지속적으로 6번 반복하여 총 3시간의 지구성 수영 운동을 실시하였고, 분석을 위한 조직 샘플링은 운동 전, 운동 후 0시간, 1시간, 4시간, 24시간에 걸쳐서 이루어졌다. 연구의 결과는 서로 다른 식이 섭취와 운동에 따른 AMPK의 신호전달 단백질의 발현은 유의한 치이가 나타나지 않았다. 그러나 서로 다른 식이를 섭취한 쥐의 근육에서 ERK 1/2(p<.01)와 p38 MAPK(p<.001)의 신호전달 단백질의 발현은 유의한 차이를 보였다(p<.05). 흥미로운 결과는 운동에 대한 유의한 차이는 AMPK, ERK1/2와 p38 MAPK 모두 유의한 차이를 보이지 않았다는 것이다. 결론적으로 일회 지구성 운동보다 서로 다른 식이의 섭취가 근육 내(백색 비복근)의 대사적 변화를 일으키는데 주도적인 영향을 미칠 수 있음을 시사할 수 있다.

• Journal of the Korean Applied Science and Technology
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• v.39 no.4
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• pp.507-516
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• 2022

The purpose of this study was to investigate the effect of rotational preference on body stability based on COP and EMG analysis in an quiet standing after turn in the left and right directions. The subjects of this study were 16 subjects with a high lateral preference for the right hand and foot. The subjects of this study were 16 subjects with high unilateral preference for the right hand and foot, and three rotational direction conditions (QS: quiet standing, LT: 10 turns on the left, RT: 10 turns on the right) were performed. In order to evaluate the stability in an quiet standing after turning, the results were derived and analyzed using a COP plate and an EMG. As a result of the study, LT and RT were larger than QS for all COP variables, but there was no difference according to the direction of turning. In EMG, RT showed larger muscle activity than the QS according to the rotational direction in left and right gastrocnemius. In conclusion, although all subjects had a high right lateral preference, there was no effect of rotational preference in COP, and gastrocnemius showed the effect of rotational preference.

• Journal of the Korea Convergence Society
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• v.9 no.10
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• pp.371-376
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• 2018

The purpose of this study is to clarify the effects of whole-body vibration and to provide scientific basis for effective exercise by analyzing the differences in lower extremity muscle activation according to squat position during whole body vibration. In this study, muscle activation during whole-body vibration was measured in 10 healthy males in their 20s with no orthopedic conditions during standing posture, deep squat, half squat, and heel raise squat. Muscle activation was compared by measuring the root mean square (RMS) with electromyography electrodes attached to lateral gastrocnemius, tibialis anterior, vastus lateralis, and biceps femoris. The vibration intensity was applied in combinations of the volumes of 50 and 80 and the frequencies of 10, 25, and 40 Hz in each posture. The results showed that there were differences in muscle activations of external gastrocnemius, tibialis anterior, and vastus lateralis among the position(p<.05). The heal raise squat was found to have a high muscle activation effect.

• Journal of Korean Foot and Ankle Society
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• v.15 no.1
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• pp.47-50
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• 2011

Equinus contracture of the gastrocnemius-soleus complex is associated with many foot and ankle diseases. We introduce a new simple technique that can be performed using a minimal incision with simple devices. Briefly, 0.5 cm sized medial and lateral longitudinal skin incisions are made at the level of the distal one third of the calf. The musculotendinous junction of the gastrocnemius is gently transected using an Arachnoid blade. The skin is, then, closed with non-absorbable sutures.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.5
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• pp.778-783
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• 2012

We report a rare case of non-traumatic spontaneous intramuscular mass of blood stasis, especially gastrocnemius muscle, associated with alcoholic liver cirrhosis. A 53-year-old man with alcoholic liver cirrhosis was admitted to our hospital for ICH. It was improved by Korean Medicine treatments, however, he was complaint of severe pain in left calf. Ultrasound revealed intramuscular hypoechoic mass at the left gastrocnemius muscle and we diagnose it as mass of blood stasis, which is similarly called 'hematoma' in Western medicine. Herbal extracts, acupuncture and indirect moxibustion reduced it, but the effects could not be compared as there were no reports of these kinds. It seems important to consider intramuscular mass of blood stasis as a complication of alcoholic liver cirrhosis and Ultrasound seems to be very useful in diagnosis and observation of intramuscular mass of blood stasis.

• 한국체육학회지인문사회과학편
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• v.54 no.1
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• pp.515-525
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• 2015

The purpose of this study was to compare muscular activities according to the mastery of Taekwondo kicking motions with the subjects of 8 demonstration team members and 8 undergraduates in Taekwondo major at University. The muscles mainly used for Taekwondo's front kick, tornado kick, or turning hook kick are total 8 trunk muscles and 8 lower limb muscles of the kicking foot as well as the supporting foot. Analyzing the muscular activities of those areas comparatively, the study has reached the following results. At the front kick, non-experts showed higher lower abdominal muscle, biceps thigh muscle activity of the kicking foot and lateral gastrocnemius muscle activity of the supporting foot but lower 2 spinals muscular activity than experts. At the tornado kick (or turning kick), in the turning motion, experts indicated higher activity in biceps muscle of thigh and spinalis than non-experts whereas in the kicking motion, they didn't show the difference between groups except biceps thigh muscle activity. At the turning hook kick, non-experts indicated higher lateral gastrocnemius muscle activity of the kicking foot and quadricpes femoris muscle activity of supporting foot muscular activity than experts. In summary, experts tend to use their trunk in the turning motion for rapid turning and show rather low muscular activity of their kicking foot. However, non-experts indicate high muscular activity in their kicking foot and supporting foot, which means to maintain balance in the kicking motion, they tend to make use of their lower limb more than trunk muscle, and it leads to an inefficient motion.

• Journal of The Korean Society of Integrative Medicine
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• v.5 no.4
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• pp.49-55
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• 2017

Purpose : In this study we tested the hypothesis that eucommia ulmoides (EU) extract would improve disuse-induced muscle atrophy following hindlimb immobilization. Method : The hindlimb immobilization was performed with casting tape to keep the left ankle joint in a fully extended position. The rats in EU treated group were orally administrated with eucommia ulmoides water extract. After 2 weeks of immobilization, all animals were sacrificed, and the whole gastrocnemius muscles were dissected from both legs. The morphology of right and left gastrocnemius muscles in both EU and control groups were assessed by hematoxylin and eosin staining. Results : Eucommia ulmoides extract represented the significant protective effects against the reductions of the gastrocnemius muscles weight and average cross section area to compared with Control group. Conclusion : Eucommia ulmoides has protective effects against immobilization induced muscle atrophy.