• Journal of the Ergonomics Society of Korea
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• v.20 no.2
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• pp.71-82
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• 2001

Twisting posture in lifting tasks has been identified as a risk factor of low back pain. However, it has been usually estimated in terms of compressive stress or muscular activity. Thus, this study was conducted to predict the influence on muscular fatigue during lifting simulation. Fifteen young and healthy subjects were recruited and performed isometric trunk exertions during upright standing, two-level flexions and five-level asymmetric twisting conditions. EMG signals from five primary trunk muscles in right part of body were collected during 20sec for 45 different lifting conditions. RMS(root mean square) and MPF(mean power frequency) parameters were used to analyze the EMG signals. Twisting postures were significant in right erector spinae(ERSR), right latissimus dorsi(LATR), right internal oblique(INOR) for muscular activities. Especially, when trunk was $30^{\circ}$ CCW twisting posture. ERSR and INOR activities increased respectively by 11% and 3%. Regarding the trunk muscle fatigue, we found that MPF shifts in twisting posture increased 2.3 and 2.6 times for ERSR and INOR muscles respectively. Therefore, It is probable for workers to suffer from low back disorders when they were exposed to a extreme twisting posture during prolonged lifting. This study suggests NIOSH(National Institute for Occupational Safety and Health) lifting equation needs the time-duration multiplier in addition to asymmetric multiplier.

• Archives of Plastic Surgery
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• v.50 no.2
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• pp.188-193
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• 2023

Vascular injury following traumatic knee injury quoted in the literature ranges from 3.3 to 65%, depending on the magnitude and pattern of the injury. Timely recognition is crucial to ensure the revascularization is done within 6 to 8 hours from the time of injury to avoid significant morbidity, amputation, and medicolegal ramifications. We present a case of an ischemic limb following delayed diagnosis of popliteal artery injury after knee dislocation. Even though we have successfully repaired the popliteal artery, the evolving ischemia over the distal limb poses a reconstruction challenge. Multiple surgical debridement procedures were performed to control the local tissue infection. Free tissue transfer with chimeric latissimus dorsi flap was done to resurface the defect. However, the forefoot became gangrenous despite a free muscle flap transfer. His limb appeared destined for amputation in the vicinity of tissue and recipient vessels, but we chose to use a cross-leg free flap as an option for limb salvage.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.85-95
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• 2008

This study is analyzing about application of taping by movement about shoulder joint's isometric contraction. M. college students take part in experiment. WEMG-8 and HUMAC system are used. Findings were as follows: EMG of muscle's MVIC at each angle before and after taping. 1. In flexion, EMG with taping is effective for supra spinatus at $0^{\circ}{\cdot}45^{\circ}{\cdot}90^{\circ}$, anterior deltoid at $0^{\circ}{\cdot}45^{\circ}$ and biceps brachii at $0^{\circ}{\cdot}90^{\circ}$. 2. In extension, EMG with taping is effective for triceps brachii at $0^{\circ}$, latissimus dorsi at $90^{\circ}$ and posterior deltoid at $45^{\circ}{\cdot}90^{\circ}$. 3. Each angle viewpoint, EMG of latissimus dorsi in extension can be arranged in its high order as $90^{\circ}<45^{\circ}$, $0^{\circ}$ without taping and $90^{\circ}<0^{\circ}$ respectively. EMG of posterior deltoid in extension is in its high order as $90^{\circ}<45^{\circ}<0^{\circ}$ without taping and $90^{\circ}<0^{\circ}$.

• Animal Bioscience
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• v.36 no.12
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• pp.1775-1784
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• 2023

Objective: The aim of this study was to reveal the role and regulatory mechanism of miR-188-5p in the proliferation and differentiation of goat muscle satellite cells. Methods: Goat skeletal muscle satellite cells isolated in the pre-laboratory were used as the test material. First, the expression of miR-188-5p in goat muscle tissues at different developmental stages was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). In addition, miR-188-5p was transfected into goat skeletal muscle satellite cells by constructing mimics and inhibitors of miR-188-5p, respectively. The changes of differentiation marker gene expression were detected by qPCR method. Results: It was highly expressed in adult goat latissimus dorsi and leg muscles, goat fetal skeletal muscle, and at the differentiation stage of muscle satellite cells. Overexpression and interference of miR-188-5p showed that miR-188-5p inhibited the proliferation and promoted the differentiation of goat muscle satellite cells. Target gene prediction and dual luciferase assays showed that miR-188-5p could target the 3'untranslated region of the calcium/calmodulin dependent protein kinase II beta (CAMK2B) gene and inhibit luciferase activity. Further functional studies revealed that CAMK2B promoted the proliferation and inhibited the differentiation of goat muscle satellite cells, whereas si-CAMK2B restored the function of miR-188-5p inhibitor. Conclusion: These results suggest that miR-188-5p inhibits the proliferation and promotes the differentiation of goat muscle satellite cells by targeting CAMK2B. This study will provide a theoretical reference for future studies on the molecular mechanisms of skeletal muscle development in goats.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.790-792
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• 2010

A 77-year-old man presented with a huge protruding mass on the left anterior chest wall. The tumor was resected and diagnosed as dermatofibrosarcoma protuberans (DFSP). DFSP is an uncommon, intermediate-grade mesenchymal cutaneous tumor which extends deep into subcutaneous tissue and may invade through the fascial planes and into muscle but rarely metastasize. Histologically, DFSP is composed of spindle cells arranged in an irregularly whorled or storiform pattern. The histological diagnosis can be confirmed with immunohistochemical staining for CD34. We report a case of DFSP. The tumor was completely excised and the chest wall was reconstructed using latissimus dorsi muscle flap and skin graft.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.903-906
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• 2005

The purpose of this study was to analyze the muscular force of swing using the soft golf club in comparison with the muscular force of swing using normal golf club. The subject was normal adult (twenties) and performed swing motion using normal and soft golf club. And then we compared muscular power soft golf club with normal golf club of the subject. The muscular power of the subject was measured by MP 100(BIOPAC Systems, Inc.). For the analysis of muscular power of swing using soft golf club, we measured EMG(Electromyography) of the subject. The position of muscle was deltoid, latissimus dorsi, external oblique and rectus abdominis of the upper limbs and rectus femoris, biceps femoris, gastrocnemius and soleus of the lower limbs. The result of experiment, muscle pattern of swing using soft golf club was similar to pattern of swing using normal golf club and muscular power of subjects using the soft golf was smaller than normal golf.

• Journal of the Korean Society of Safety
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• v.24 no.2
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• pp.83-88
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• 2009

The objective of this paper was to evaluate the effectiveness of horizontal, vertical, asymmetric and coupling multipliers for manual material handling. Lifting tasks with 5 different horizontal distances ($30{\sim}70cm$) for 6 vertical distances(ankle, knee, waist, elbow, shoulder and head height) were experimented. The muscle activity and muscle exertion level during asymmetric load handling(without trunk flexion) was experimented. Lifting tasks with and without handle tote box for three postures(straight, bending, right angle posture) were experimented. The degrading tendency did not appeared almost in $60{\sim}70cm$ interval's horizontal distance. As a result of ANOVA, MVC paid attention to horizontal and vertical distance but cross effect was insignificant(p<0.01). The change of the MVC according to the horizontal, vertical distance appeared similar from of RWL. The results of normalized MVC measurement were decreased about 16%, 24%, 34% respectively as the asymmetry angle was $30^{\circ}$, $60^{\circ}$, $90^{\circ}$. RMS EMG values of right erector spinae muscles were decreased as the work posture went to $90^{\circ}$ and those of left erector spinae muscles were increased until the asymmetry angle was $40^{\circ}$ but decreased continually over $40^{\circ}$. 7 subjects, activities of left and right latissimus dorsi muscles were maintained constantly, while for remainer, those were irregular. MVC reduced maximum 23% by type of handle. MVC was highest in straight posture, but was lowest in right angle posture. As a result of ANOVA, MVC paid attention to posture, coupling(p<0.01). To all handle types, biceps brachii activity was increased in right angle posture, but reduced in straight posture. Based on the results of this study, it is suggested that the NIOSH guideline should not be directly applied to Korean without reasonable reexamination. In addition, we need to afterward study through an age classification.

• Horticultural Science & Technology
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• v.34 no.6
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• pp.940-958
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• 2016

The objective of this study was to analyze the kinematic and kinetic characteristics of two horticultural activities: seed sowing and planting plant. Thirty-one male university students (aged $26.2{\pm}2.0years$) participated in this study. Kinematic factors (movement times, peak velocity, joint angles, and grasp patterns) were assessed using a three-dimensional motion analysis system while the subjects performed the horticultural activities. Kinetic factors (muscle activation of eight upper-limb muscles: the anterior deltoid, serratus anterior, upper trapezius, infraspinatus, latissimus dorsi, biceps brachii, brachioradialis, and flexor carpi radialis) were assessed using surface electromyography. The acts of seed sowing and planting plant were comprised of five tasks which included six types of phases: reaching, grasping, back transporting, forward transporting, watering, and releasing. The movement times, peak velocity, joint angles, and grasp patterns were significantly different across the tasks involved in the horticultural activities. All eight muscles of the upper limbs were utilized during the horticultural activities, and the muscle activation of the serratus anterior was the highest compared to that of the other muscles tested. The kinematic and kinetic characteristics of these horticultural activities showed similar characteristics to reaching and grasping rehabilitation training and daily living activities. The present study provides reference data for common horticultural activities using a kinematic and kinetic analysis.

• Archives of Plastic Surgery
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• v.46 no.1
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• pp.39-45
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• 2019

Background The dorsolateral branch of the posterior intercostal artery (DLBPI) can be easily found while harvesting a latissimus dorsi (LD) musculocutaneous flap for breast reconstruction. However, it remains unknown whether this branch can be used for a free flap and whether this branch alone can provide perfusion to the skin. We examined whether the DLBPI could be reliably found and whether it could provide sufficient perfusion. Methods We dissected 10 fresh cadavers and counted DLBPIs with a diameter larger than 2 mm. For each DLBPI, the following parameters were measured: distance from the lateral margin of the LD muscle, level of the intercostal space, distance from the spinal process, and distance from the inferior angle of the scapula. Results The DLBPI was easily found in all cadavers and was reliably located in the specified area. The average number of DLBPIs was 1.65. They were located between the seventh and eleventh intercostal spaces. The average length of the DLBPI between the intercostal space and the LD muscle was 4.82 cm. To assess the perfusion of the DLBPIs, a lead oxide mixture was injected through the branch and observed using X-rays, and it showed good perfusion. Conclusions The DLBPI can be used as a pedicle in free flaps for small defects. DLBPI flaps have some limitations, such as a short pedicle. However, an advantage of this branch is that it can be reliably located through simple dissection. For women, it has the advantage of concealing the donor scar underneath the bra band.

• Journal of Chest Surgery
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• v.32 no.5
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• pp.428-432
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• 1999

Background: It has been shown that low-grade electrical stimulus can transform fatigue resistant muscles which then can be used to protect the heart. The bulky and cumbersome power sources of the artificial heart or implantable ventricular assist devices are still in need of solution; however, on the other hand, the implantable ventricular assist devices using the resistant muscles as the power source have the advantages of using its own muscle contractions. The purpose of this study was to determine the possibility of a clinical application of the skeletal muscle ventricle. Material and Method: Latissimus dorsi muscles (LDM) of 8 canines were used for skeletal muscle ventricle. A latex chamber was wrapped one and a half times with LDM. The chamber was attached to a pressure transducer via Tygon tube. An electrode stimulator was placed around the thoracodorsal nerve and LDM was stimulated in cyclic bursts of 0.31 sec on time and 6.0 sec off time using 3.0 volt Itrel stimulator. The preload volume was added to the system in 25cc increments. Ejection volumes, pressures, and peak power outputs were measured. Result: Ejection volume was 76.3cc with 0cc of preload. Ejection volumes were less than 70ml with increments of preload over 75cc Pressures were more than 107 mmHg when the preloads were less than 75cc and less than 100 mmHg when the preloads were more than 100cc. Peak power output of 16.6 W/kg was observed at 50cc preload. Conclusion: Depending on the changes of preload, the volumes ejected from skeletal muscle ventricle and pressures from the skeletal muscle contraction surpassed those of the normal heart. These data suggest that there are clinical applications for skeletal muscle ventricular assist system.