• Journal of the Korean Society of Systems Engineering
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• v.20 no.spc1
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• pp.76-89
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• 2024

This study investigates the impact of standardized underground logistics conainers on lower body muscle activation during warehouse tasks, comparing conventional roll containers(A type) with newly developed ones(B type). Through a detailed experimental setup involving electromyography(EMG) and tensiomyography(TMG), muscle activities of the lower limbs were quantitatively analyzed during loading unloading and transporting tasks. Results indicated no significant difference in muscle activation patters between the two rolltainer types, suggesting that the dimensions of these containers do not critically affect the muscular strain and workload. Furthermore, the TMG analysis revealed that muscle contraction velocity(Vc) increased in certain muscles when using the B-type rolltainer, indicating a potential for more efficient muscle engagement without increasing fatigue. This research underscores the importance of ergonomic considerations in the design of logistics equipment and suggests that further studies should focus on optimizing the interaction between human operators and logistical systems to enhance safety and efficiency in warehouse operations.

• Journal of Digital Convergence
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• v.18 no.2
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• pp.483-487
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• 2020

In this study, the effects of suspension training according to the types of ground. Fourteen healthy male college students measured for the characteristics of core muscle activity in suspension training on two different types of grounds, normal flat and unstable ground using a gym ball. EMG (Electromyography) was exploited to measure the activity of the core muscles according to the types of the ground. Muscle activity of the abdominal muscles, external oblique muscles, internal oblique muscles, and lower lumbar standing muscles was measured. The variables in analyses were measured by the means of % MVC method to standardize the EMG signal according to the ground type for each core muscle. In order to verify the differences in core muscles according to the type of ground the paired t-tests were performed at the significance level of 0.05 (p<.05). As a result of measuring the activity of the core muscles according to the various types of grounds, the difference between muscle characteristics obtained in two different grounds did not appear to be statistically significant. However, the result is an important clue to reconsider the notion that the training effect on the unstable ground is generally superior to the effect on the stable ground in the core muscle training. The type of ground in the core muscle training has been found not to significantly affect the muscle activation according to the results of this study. Regardless of the type of exercise program, hence, the difference in muscle activation will not be insignificant even with the standardized program strengthening core muscles.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.4
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• pp.593-600
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• 2013

PURPOSE: We investigated the relationship between personality, music type and MVIC, power for the knee extensor on inducing muscle fatigue. METHODS: The subjects of this study were 22 healthy students. MVIC(Maximum Voluntary Isometric Contraction) and power in knee extension was measured by PRIMUS RS. Personality types was measured by MBTI(Myers-Briggs Type Indicator) that is an instrument designed to provide descriptive profiles of personality types and preferences. The collected data were analyzed using the independent t-test, MANOVA and Pearson-test. RESULTS: There was no significant differences both MVIC and power of the knee extensor according to personality and music type. The power was significantly increased by increasing the MVIC during a knee extension on inducing muscle fatigue without music type(r= .786~.896). There was no significant correlation both MVIC and power of the knee extensor according to personality. CONCLUSION: There was a positive correlation between power and MVIC during a knee extension on inducing muscle fatigue without music type. There was no significant correlation both MVIC and power of the knee extensor according to personality.

• Journal of Korean Medicine Rehabilitation
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• v.29 no.1
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• pp.7-20
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• 2019

Objectives The purpose of this study was to improve the comfort of daily life such as reduction of headache and increase of movement of neck by using muscle relaxation approach and joint movement approach for office worker with tension type headache of foward head posture sitting over 5 hours. Methods For this, 9 male and 15 female participated in the foward head posture with tension type headache. Each group consisted of 3 male and 5 female. Groups are divided into groups, such as muscle relaxation therapy, joint movement therapy, muscle relaxation and joint movement therapy. After intervention for each group for a month, we measured neck movement and head disability index and neck disability index 2 week. SPSS 23.0 (IBM Corp., Armonk, NY, USA) was used for data analysis. The one-way repeated analysis of variance (ANOVA), one-way ANOVA, compared t-test was used for statistical analysis. Results Three intervention groups have brought improvements in neck movement and daily life comfort. There is significant difference in the improvement of neck extension and change in neck disability index between 2 and 4 weeks in the joint movement approach compared to muscle relaxation approach, muscle relaxation and joint movement approach. Conclusions Office workers are exposed to tension type headache. However, muscle relaxation approach and joint movement approach can improve neck movement and daily life comfort.

• Korean Journal of Applied Biomechanics
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• v.25 no.1
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• pp.77-84
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• 2015

Objective : The purpose of this study was to analyze the effects of lower limb muscle activity on postural stability and ground type in elderly women subjects. Method : Forty two subjects participated in the experiment (high group - age: $74.29{\pm}4.13yr$, height: $152.44{\pm}5.54cm$, weight: $57.43{\pm}6.16kg$, BMI: $24.77{\pm}2.99$, low group - age: $77.67{\pm}5.16yr$, height: $151.40{\pm}3.93cm$, weight: $60.92{\pm}6.40kg$, BMI: $26.59{\pm}2.57$). Wireless EMG with eight channels was used. Ground types were classified as flat and cushion. Results : In the double-support phase, left and right rectus femoris, left biceps femoris, left and right tibialis anterior, and left gastrocnemius did not show a significant difference in postural stability according to ground type. However right biceps femoris and gastrocnemius showed higher muscle activity in the elderly women group with lower postural stability. In the single-support phase, left and right rectus femoris, right biceps femoris, and left and right tibialis anterior did not show a significant difference in postural stability according to ground type. In addition, left biceps femoris had higher muscle activity in the elderly women group with lower postural stability. Left gastrocnemius had higher muscle activity in the elderly women group with higher postural stability and right gastrocnemius had higher muscle activity in the elderly women group on cushion ground. Conclusion : In a dynamic postural stability and cushion ground, biceps femoris and gastrocnemius muscle activity were high. As a result, biceps femoris and gastrocnemius muscle strengthening exercise on cushion ground could be beneficial in the prevention of falling.

• Fashion & Textile Research Journal
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• v.19 no.4
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• pp.504-514
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• 2017

Discomfort as well as muscular pain and musculoskeletal diseases occur in cases of stressed posture due to prolonged pressure. Therefore, the American Academy of Orthopaedic Surgeons (AAOS) and Pediatric Orthopaedic Society of North America (POSNA) recommend that bags that weigh no more than 15 - 20% of the wearer's weight. However, despite the prolonged pressure from using baby carriers, there are no recommendations and limited studies on how to protect wearers. Therefore, this study investigates subjective fatigue according to the usage of waist support and hip seat. Based on this, muscle fatigue and secondary subjective fatigue according to three types of currently commercial baby carriers (X-type, H-type, and H-hip type) were measured. Subjective comfortability was evaluated on a 5 point Likert-scale and subjective fatigue was evaluated on Borg's CR-10 scale. Objective muscle fatigue was also compared by measuring and analyzing electromyogram (EMG). The results of primary subjective fatigue showed statistically significant changes in the shoulders, waist, calves, and soles of the feet according to the usage of hip seats and waist support. Electromyogram measurements also showed less muscle fatigue at the upper trapezius muscle and thoracic erector spine muscle for the H-hip seat baby carrier, which has both waist support and hip seat, compared to an X-type baby carrier, which has neither. However, results of subjective fatigue showed opposite results at the waist despite having same results at the shoulders and beneath the shoulders. This show discrepancies between objective muscle fatigue and subjective fatigue; therefore, that both aspects must be taken into consideration when developing ergonomic baby carriers.

• Journal of Digital Convergence
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• v.12 no.12
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• pp.651-658
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• 2014

The purpose of this study is to see how the sling lumbar stabilization exercise affects muscle body type and subjective pain degree of 17 middle-age men who are diagnosed with sacroiliac joint syndrome and investigate the effectiveness. The subjects of this study are patients who have been diagnosed with sacroiliac joint syndrome through tests like X-ray in S Orthopedics in C City and have had chronic lumbar pain for more than 6 months and the before and after results about subjective pain degree through three dimension Moire Muscle Body Type Tester and subjective pain degree through VAS Pain Awareness after sling lumbar stabilization exercise 3 times a week, 30 minutes a time, total 24 times for 8 weeks have revealed the following: The change of muscle body type has been comprehensively improved in the statistics before and after the exercise and the subjective pain degree has also comprehensively decreased in the statistics. Therefore, sling lumbar stabilization exercise is proved to give positive affect to muscle body type and pain improvement of the patients with sacroiliac joint syndrome.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.5
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• pp.665-671
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• 2010

Muscle fiber characteristics and their relationship to water-holding capacity of longissimus dorsi (ld) muscle were studied in Brahman (BRA) and Charolais (CHA) crossbred bulls fattened under practical farm conditions. Thirty-four BRA and 34 CHA bulls were randomly selected and slaughtered at 500, 550 and 600 kg live weight. Parameters of water-holding capacity such as drip, ageing, thawing, cooking and grilling loss were determined. Muscle fiber characteristics were conducted for muscle fiber type percentage and cross-sectional areas of slow- and fast-twitch fiber types, and correlation coefficients to water-holding capacity parameters were calculated. Results showed that CHA meat had a better water-holding capacity (less ageing, thawing and grilling loss) when compared with BRA, whereas slaughter weights had no significant effects on these parameters. Furthermore, there were no significant differences between genotypes and slaughter weights in muscle fiber type percentage and cross-sectional areas of ld muscle. Slow- and fast-twitch fiber types of all experimental groups averaged 24.4 and 75.6%, respectively. Cross-sectional areas of fast-twitch fibers had almost twice the size of slow-twitch fibers (6,721 and 3,713 ${\mu}m^2$, respectively). The correlation between muscle fiber area and water-holding capacity indicated that muscles with larger fiber areas had a lower drip and ageing loss but a higher cooking and grilling loss.

• Diabetes and Metabolism Journal
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• v.42 no.6
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• pp.465-471
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• 2018

My professional journey to understand the glucose homeostasis began in the 1990s, starting from cloning of the promoter region of glucose transporter type 2 (GLUT2) gene that led us to establish research foundation of my group. When I was a graduate student, I simply thought that hyperglycemia, a typical clinical manifestation of type 2 diabetes mellitus (T2DM), could be caused by a defect in the glucose transport system in the body. Thus, if a molecular mechanism controlling glucose transport system could be understood, treatment of T2DM could be possible. In the early 70s, hyperglycemia was thought to develop primarily due to a defect in the muscle and adipose tissue; thus, muscle/adipose tissue type glucose transporter (GLUT4) became a major research interest in the diabetology. However, glucose utilization occurs not only in muscle/adipose tissue but also in liver and brain. Thus, I was interested in the hepatic glucose transport system, where glucose storage and release are the most actively occurring.

• The Journal of the Korean dental association
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• v.50 no.10
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• pp.620-623
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• 2012

The use of botulinum toxin type A in the lower face has increasingly popular. And treatment of the depressor anguli oris muscle(DAO) and the mentalis muscle(MT), particularly in combination with filler substances, produces a remarkable improvement in the lower aged face. The aim of this study was to demonstrate the topographical anatomy of the DAO, MT, and their related structures, thereby providing critical information for determining the safest and most effective site for BTX-A injections. The most effective injection sites of DAO and MT were suggested based on the new anatomical knowledge of the lower face.