• Journal of Korean Physical Therapy Science
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• v.29 no.1
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• pp.64-72
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• 2022

Background: The purpose of this study is to investigate the effect of wall squat exercise according to the difference in the support surface on the thickness change of external oblique, internal oblique and transverse abdominalis of the trunk muscles and the change in distance of center of pressure when the eyes are opened and closed. Design: Randomized controlled trial. Methods: The subjects were 26 healthy adults, 18 males and 8 females. The composition of each group using the single-blind method was 13 people in the unstable side wall squat exercise group and 13 people in the stable side wall squat exercise group. Experimental measurements were divided into before, 3 weeks, and 6 weeks after the experiment, and changes in muscle thickness and balance were confirmed. Muscle thickness was measured using ultrasinic, and static balance change was measured using Bio-rescue. Results: There were significant differences in the thickness changes of external oblique, internal oblique and transverse abdominalis according to the wall squat exercise method by period and in the interaction between the period and the group (p<0.05). As a result of the post-hoc analysis, there was a significant difference in the change between the two groups in external oblique muscle after 6 weeks. And there was a significant difference in the distance of the pressure center between eyes open and closed eyes (p<0.05). Conclusion: In terms of instability, wall squat exercise was positive for changes in trunk muscle thickness. It suggests the possibility of using it for trunk muscle strengthening training in the future.

• Physical Therapy Rehabilitation Science
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• v.9 no.4
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• pp.287-294
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• 2020

Objective: This study aimed to investigate the effects of an ultrasound-based bar graph proportional to the quadriceps muscle thickness as a real-time visual feedback training tool in the elderly. Design: Cross-sectional study. Methods: Twenty-four elderly persons participated in this study and were randomly divided into three groups: oral training group (n=8, group 1), ultrasound imaging group (n=8, group 2), and graph group (n=8, group 3). In the pre condition, all participants performed maximal voluntary isometric contraction (MVIC) of the quadriceps with knee extension three times with oral training. In the post condition, group 1 performed MVIC of the quadriceps with oral training, group 2 performed MVIC of the quadriceps with real-time visual feedback using ultrasound imaging, and group 3 performed MVIC of the quadriceps with real-time visual feedback using a bar graph proportional to the quadriceps muscle thickness, three times for all groups. Muscle thickness, activity (mean, peak), tone, stiffness, logarithmic decrement, relaxation, and creep were measured in both conditions in all participants. Results: Visual feedback with a bar graph showed significant effects on muscle thickness, mean muscle activity, and peak muscle activity compared with oral training and visual feedback with ultrasound imaging (p<0.05). Conclusions: Isometric training of the quadriceps with real-time visual feedback using a bar graph proportional to the quadriceps muscle thickness may be more effective than other methods in improving muscle thickness and muscle activity. This study presented a tool that can help increase muscle thickness in the elderly.

• Journal of the Korean Society of Physical Medicine
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• v.17 no.4
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• pp.53-63
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• 2022

PURPOSE: This study examined the changes in the thickness of the abdominal muscles, including the transversus abdominis, according to the set pressure applied by a pressure biofeedback unit during contractions of the hip adductor muscles. METHODS: After randomizing 40 healthy adult males in their 20 s and 30 s, the participants were instructed to match the pressure gauge indication of the pressure biofeedback device to continue contracting the hip adductor while maintaining it at 10 mmHg (low), 40 mmHg (medium), or 70 mmHg (high). The measurement was taken over five seconds using an ultrasound device. RESULTS: According to the contractile pressure applied to the hip adductor muscle, there was a significant difference in the muscle thickness change of the transverse abdominis muscle between 10 mmHg and 70 mmHg and between 40 mmHg and 70 mmHg. The muscle thickness ratio of the external oblique/abdominal muscle was significantly different between 10 mmHg and 70 mmHg and between 40 mmHg and 70 mmHg. CONCLUSION: Increased contraction pressure on the hip adductor muscle increases the muscle thickness of the abdominal transverse muscle. Interbody stability exercise with contractions of the hip adductor muscle is expected to help increase in the muscle thickness of the hip adductor muscle.

• Tribology and Lubricants
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• v.38 no.5
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• pp.199-204
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• 2022

This paper presents a numerical investigation of the influence of water molecule thickness on frictional behavior at the nanoscale using molecular dynamics simulation. Three different models, comprising water thin films of various thicknesses, were built, and indentation and sliding simulations were performed using the models. Various normal loads were applied by indenting the Si tip on the water film for the sliding simulation to evaluate the interplay between the water thin film thickness and the normal load. The results of the simulations showed that the friction force generally increased with respect to the normal load and thickness of the water thin film. The friction coefficient varied with respect to the normal load and the water film thickness. The friction coefficient was the smallest under a moderate normal force and increased with decreasing or increasing normal loads. As the water film became thicker, the contact area between the tip and water film became larger. Under well-lubricated conditions, the friction force was proportional to the contact area regardless of the water film thickness. As the normal force increased above a critical condition, the water molecules beneath the Si tip spread out; thus, the film could not provide lubrication. Consequently, the substrate was permanently deformed by direct contact with the Si tip, while the friction force and friction coefficient significantly increased. The results suggest that a thin water film can effectively reduce friction under relatively low normal load and contact pressure conditions. In addition, the contact area between the contacting surfaces dominates the friction force.

• Journal of Advanced Technology Convergence
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• v.2 no.2
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• pp.31-38
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• 2023

This study compares the correlation between muscle thickness (abdominal, quadriceps muscle) and how the muscle thickness affects the static balance when the static balance is measured in a standing position. The subjects of study were to select 29 subjects to find out what relationship muscle thickness had on the static balance when measuring muscle thickness and static balance. rectus femoris muscle thickness showed a significant correlation in statically balanced weight distribution index. In this study, only healthy men in their twenties were selected, and the results could not be generalized to other age groups. As a limitation of this study, muscle strength and peripheral vision were not measured, so it seems difficult to express the accuracy of the study and generalize the results. In future studies, the number of subjects and muscle strength should be measured to proceed with the study.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.30 no.1
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• pp.85-93
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• 2024

Background: This study examined the Immediate effects of IASTM using microcurrent and the flossing band on the lower extremity fascia thickness in subjects with Intrinsic patellofemoral pain syndrome. Methods: Sixty-six subjects with patellofemoral pain syndrome were randomized into three groups (22 each in the microcurrent IASTM (instrument assisted soft-tissue mobilization) group, and flossing band group, and combined microcurrent IASTM and flossing band group) to evaluate the immediate effects of the lower extremity fascia thickness before and after intervention. The thickness of the lower extremity fascia was measured using an ultrasound machine. Using SPSS Window. 22.0, a Shapiro Wilk was conducted to test the normality of all variables; within-group comparisons were made with a paired-samples t-test, and between-group interventions were subjected to a one-way analysis of variance. Results: Changes in the thickness of the fascia in the thigh area were observed before and after intervention in all three groups. There was a significant decrease, and in the combined group, there was a significant decrease in fascia thickness compared to when the IASTM group and the flossing band group were applied separately (p<.05). Conclusion: Through this study, the effect on fascia thickness was confirmed when IASTM and flossing band intervention were combined, and it is believed that it can be used as basic clinical data for patients with knee-thigh pain syndrome.

• Archives of Plastic Surgery
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• v.50 no.6
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• pp.601-609
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• 2023

Background The anterolateral thigh (ALT) flap is a preferred option in the reconstruction of a wide variety of defects, enabling multiple tissue components and thicknesses. Methods This study was conducted to investigate the correlation of the thickness of the traditional subfascial ALT flap and superficial fat flap with age, gender, and body mass index (BMI). A total of 42 patients (28 males and 14 females) were included in the study. Results Mean age was 50.2 (range, 16-75) years and mean BMI was 24.68 ± 4.02 (range, 16.5-34.7) kg/m². The subfascial flap thickness was significantly thinner in male patients (16.07 ± 2.77 mm) than in female patients (24.07 ± 3.93 mm; p < 0.05), whereas no significant difference was found between male (4.28 ± 1.15 mm) and female patients (4.85 ± 1.09 mm) regarding superficial fat flap thickness (p = 0.13). The thickness of both flaps had a positive correlation with BMI, and the strongest correlation was found for subfascial ALT thickness in female patients (r = 0.81). Age had no effect on both flap thickness measurements. The anterior thigh is thicker in women than in men, although it varies according to BMI. This shows that flap elevation is important in the superthin plane, especially if a thin flap is desired in female patients in defect reconstruction with the ALT flap. Thus, a single-stage reconstruction is achieved without the need for a defatting procedure after subfascial dissection or a second defatting procedure 3 to 6 months later. Conclusion The appropriate ALT flap plane should be selected considering the gender and BMI of the patient.

• Steel and Composite Structures
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• v.52 no.2
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• pp.237-248
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• 2024

In order to make the dynamic analysis and design of improved composite beam with corrugated steel web (CBGSCC) bridge more efficient and economical, the parametric self-cyclic analysis model (SCAM) was written in Python on Anaconda platform. The SCAM can call ABAQUS finite element software to realize automatic modeling and dynamic analysis. For the CBGSCC bridge, parameters were set according to the general value range of CBGSCC bridge parameters in actual engineering, the SCAM was used to calculate the large sample model generated by parameter coupling, the optimal value range of each parameter was determined, and the sensitivity of the parameters was analyzed. The number of diaphragms effects weakly on the dynamic characteristics. The deck thickness has the greatest influence on frequency, which decreases as the deck thickness increases, and the deck thickness should be 20-25 cm. The vibration frequency increases with the increase of the bottom plate thickness, the web thickness, and the web height, the bottom plate thickness should be 17-23mm, the web thickness should be 13-17 mm, and the web height should be 1.65-1.7 5 m. Web inclination and Skew Angle should not exceed 30°, and the number of diaphragms should be 3-5 pieces. This method can be used as a new method for structural dynamic analysis, and the importance degree and optimal value range of each parameter of CBGSCC bridge can be used as a reference in the design process.

• Corrosion Science and Technology
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• v.14 no.2
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• pp.99-105
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• 2015

The structures of reinforced concrete have been extensively increased with rapid development of industrial society. Futhermore, these reinforced concretes are easy to expose to severe corrosive environments such as seawater, contaminated water, acid rain and seashore etc.. Thus, corrosion problem of steel bar embedded in concrete is very important in terms of safety and economical point of view. In this study, specimens having six different coating thickness (W/C:0.5) were prepared and immersed in flowing seawater for five years to evaluate the effect of coating thickness and immersion time on corrosion property. The polarization characteristics of these embedded steel bars were investigated using electrochemical methods such as corrosion potential, anodic polarization curve, and impedance. At the 20-day immersion, the corrosion potentials exhibited increasingly nobler values with coating thickness. However, after 5-yr. immersion their values were shifted in the negative direction, and the relationship between corrosion potential and coating thickness was not shown. Although 5-yr. immersion lowered corrosion potential, 5-yr. immersion did not increase corrosion rate. In addition, after 5-yr. immersion, the thinner cover thickness, corrosion current density was decreased with thinning coating thickness. It is due to the fact that ease incorporation of water, dissolved oxygen and chloride ion into a steel surface caused corrosion and hence, leaded to the formation of corrosion product. The corrosion product plays the role as a corrosion barrier and increases polarization resistance. The corrosion probability evaluated depending on corrosion potential may not be a good method for predicting corrosion probability. Hence, the parameters including cover thickness and passed aged years as well as corrosion potential is suggested to be considered for better assessment of corrosion probability of reinforced steel exposed to partially or fully in marine environment for long years.

• Archives of Craniofacial Surgery
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• v.10 no.2
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• pp.67-70
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• 2009

Purpose: Anatomical basis around orbit can be helpful in periorbital surgery, and there are many articles about measurement between periorbital reference points. In 1967, Jones and Evans measured the orbital wall thickness of Asian cadavers and this article has been cited more than 50 times. But there is no research in orbital thickness in Vivo. Author's idea was based on difference between live human and human cadaver. Material & Method: We conducted this study from 63 consecutive blow out fracture patients between January, 2000 to june, 2005 by collecting the bone fragments and measured the thickness of that fragment using vernia calipers. Anatomically, orbital floor is separated two area by inferior orbital fissure and we measured each area. Three areas were zone I (medial wall), zone II (medial to inferior orbital fissure) and zone III (lateral to inferior orbital fissure). Result: When the overall results were considered, the thickness of Zone I (medial wall of orbit) was average $0.131{\pm}0.006mm$ in male and $0.129{\pm}0.007mm$ in female and Zone II (medial side of orbital floor) was $0.251{\pm}0.005mm$ in male and $0.245{\pm}0.006mm$ in female, Zone III (lateral side of orbital floor) was $0.237{\pm}0.006mm$ in male and $0.226{\pm}0.006mm$ in female. There were no statistical difference between orbital wall thickness of male and female. Also, orbital wall thickness of adults measured $0.130{\pm}0.005mm$, $0.250{\pm}0.005mm$, $0.232{\pm}0.006mm$ in Zone I, Zone II, Zone III and $0.128{\pm}0.006mm$, $0.233{\pm}0.005mm$, $0.215{\pm}0.007mm$ in Zone I, Zone II, Zone III from childs, and there were no statistical difference between adult and child. Conclusion: This article is the first study about Korean orbital wall thickness, and can be helpful to periocular surgery.