• The Journal of Korean Physical Therapy
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• v.28 no.2
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• pp.136-141
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• 2016

Purpose: In this study experiments were performed during 6 weeks with 40 adults, 20 subjects in the waist stabilization exercise with blood flow restriction group and 20 subjects in the waist stabilization exercise without blood flow restriction group, in order to determine the impact of waist stabilization exercise on White Area Index (WAI) followed by blood flow restriction. Methods: Thickness of external oblique abdominal muscle, internal oblique abdominal muscle, and transversus abdominis muscle, as well as density and WAI of external oblique abdominal muscle were measured, followed by performance of repeated ANOVA. Results: Significant difference in thickness of external oblique abdominal muscle according to periodical difference was observed between groups (p<0.05). Significant difference in thickness of internal oblique abdominal muscle and transversus abdominis muscle according to periodical difference was observed between groups (p<0.05). Significant difference in density and WAI of external oblique abdominal muscle according to periodical difference was observed between groups (p<0.05). Conclusion: In conclusion, significant difference was observed after waist stabilization exercise with blood flow restriction. These results can be used as basic data for future research on waist stabilization exercise and blood flow restriction exercise.

• The Journal of Korean Physical Therapy
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• v.29 no.2
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• pp.69-73
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• 2017

Purpose: This study was conducted to investigate the effects of blood flow restriction and different support surfaces for bridge exercises on the thickness of the transverse abdominis and multifidus, which are trunk-stabilizing muscles. Methods: The study's subjects were 45 adults who were divided into three groups that performed bridge exercises over a six-week period on their respective support surfaces after blood flow restriction. Changes in the thickness of the subjects' transverse abdominis and multifidus muscles were measured using ultrasonography before the experiment, then three and six weeks after the experiment. The changes in each variable over time were analyzed using a repeated-measures analysis of variance (ANOVA). Results: The transverse abdominis showed significant differences in muscle thickness with regard to time and the interaction between time and each group (p<0.05), but no significant differences with regard to changes among groups (p>0.05). The multifidus showed significant differences in muscle thickness with regard to time, the interaction between time and each group, and changes between groups (p<0.05). Conclusion: Blood flow restriction and different support surfaces for bridge exercises led to significant differences in the thickness of the transverse abdominis and multifidus. This study's results may be used as the basis for future studies and for rehabilitation in clinical practice.

• Journal of Korean Physical Therapy Science
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• v.29 no.2
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• pp.48-56
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• 2022

Background: This study was to identify the effects of blood flow restriction on gluteus muscles thickness, density, and white area index for children with cerebral palsy. Design: Randomized controlled trial. Methods: Twenty children with cerebral palsy were assigned randomly to an experimental (n=10) or control (n=10) group. The experimental group performed a bicycle exercise after blood flow restriction. The control group performed a bicycle exercise. The study used an ultrasonic instrument to measure gluteus muscles thickness, density, and WAI. Wilcoxon signed ranks test was used for determination of differences before and after treatment, and a Mannn-whitney U test was used for determination of differences between treatment groups. Results: As a result of comparison within groups, the experimental and control group showed significant difference for gluteus muscles thickness, density, and WAI after the experiment (p<0.05). In comparison between two groups, the experimental group showed more significant difference in gluteus muscles thickness, density, and WAI than the control group (p<0.05). Conclusion: Based on these results, a bicycle exercise after blood flow restriction effectively improved the gluteus muscles thickness, density, and WAI of children with cerebral palsy.

• PNF and Movement
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• v.20 no.1
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• pp.31-39
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• 2022

Purpose: The purpose of this study was to identify the effects of general exercise after blood flow restriction on trunk muscles thickness in children with spastic cerebral palsy. Methods: Twenty children with cerebral palsy were assigned randomly to an experimental (n = 10) or a control (n = 10) group. The experimental group performed general exercise after blood flow restriction, while the control group performed general exercise alone. The study used an ultrasonic instrument to measure trunk muscles thickness. The Wilcoxon signed-rank test was used to determine differences before and after treatment, and the Mann-Whitney U test was used to determine differences between treatment groups. Results: From a comparison within the groups, the experimental and control groups showed significant difference in trunk muscle thickness after the experiment (p < 0.05). In a comparison between the two groups, the experimental group showed more significant difference in trunk muscle thickness than the control group (p < 0.05). Conclusion: Based on these results, general exercise after blood flow restriction effectively improves trunk muscle thickness in children with cerebral palsy.

• The Journal of Korean Physical Therapy
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• v.29 no.2
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• pp.80-84
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• 2017

Purpose: This study was conducted to examine the effects of different sizes of blood flow restriction areas on the thickness of the external oblique and biceps brachii. Methods: The study subjects were 52 adults who were divided into four groups that performed plank exercises over a six-week period after blood flow restriction. Changes in the thickness of the external oblique and biceps brachii were measured using ultrasonography before the experiment, then three and six weeks after the experiment. The changes in each variable over time were evaluated by repeated-measures analysis of variance (ANOVA). Results: The external oblique and biceps brachii showed significant differences in muscle thickness with regard to time and the interaction between time and each group (p<0.01), but no significant differences with regards to changes between groups (p>0.05). Conclusion: A larger blood flow restriction area resulted in a statistically significant increase in muscle thickness. The results of this study may be used as the basis for future studies and for rehabilitation in clinical practice.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.643-646
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• 2001

This paper investigates the structural analysis and design of mechanical heart valve through the numerical analysis methodology. In a numerical analysis methodology application to the thickness minimization structural design of mechanical heart valve, structural analysis is performed for the blood flow through a bileaflet mechanical heart valve. The structural static analysis is carried out to confirm the thickness minimization structural condition (minimum thickness shape of leaflet).

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.4
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• pp.5-12
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• 2003

This paper discusses about the thickness effects on the structural durability of a bileaflet mechanical heart valve (MHV). In the study on the design and the mechanical characteristics of a bileaflet mechanical heart valve, the fluid mechanics analysis on the blood flow passing through leaflets, the kinetodynamics analysis on the rigid body motion of the leaflet induced by the pulsatile blood flow, and the structural mechanics analysis for the deformed leaflet are required sequentially and simultaneously. Fluid forces computed in the fluid mechanics analysis on the blood flow are used in the kinetodynamics analysis for the leaflet motion. Thereafter, the structural mechanics analysis for the deformed leaflet follows to predict the structural strength variation of the leaflet as the leaflet thickness changes. Analysis results show that structural deformations and stresses increase as the fluid pressure increases and the leaflet thickness decreases. Analysis results also show that the leaflet becomes structurally weaker and weaker as the leaflet becomes thinner and thinner.

• Journal of Mechanical Science and Technology
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• v.17 no.9
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• pp.1316-1323
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• 2003

This paper presents a structural analysis on the rigid and deformed motion of the leaflet induced by the blood flow required in the design of a bileaflet mechanical heart valve (MHV) prosthesis. In the study on the design and the mechanical characteristics of a bileaflet mechanical heart valve, the fluid mechanics analysis on the blood flow passing through leaflets, the kinetodynamics analysis on the rigid body motion of the leaflet induced by the pulsatile blood flow, and the structural mechanics analysis on the deformed motion of the leaflet are required sequentially and simultaneously. Fluid forces computed in the previous hemodynamics analysis on the blood flow are used in the kinetodynamics analysis on the rigid body motion of the leaflet. Thereafter, the structural mechanics analysis on the deformed motion of the leaflet follows to predict the structural strength variation of the leaflet as the leaflet thickness changes. Analysis results show that structural deformations and stresses increase as the fluid pressure increases and the leaflet thickness decreases. Analysis results also show that the leaflet becomes structurally weaker and weaker as the leaflet thickness becomes smaller than 0.6 mm.

• Korean Journal of Computational Design and Engineering
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• v.6 no.1
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• pp.59-68
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• 2001

This paper investigates the structural analysis and design of mechanical heart valve through the numerical analysis methodology. In a numerical analysis methodology application to the thickness minimization structural design of mechanical heart valve, fluid analysis is performed for the blood flow through a bileaflet mechanical heart valve. Simultaneously the kinetodynamic analysis is carried out to obtain the appropriate structural condition for the structural analysis. Thereafter the structural static analysis is also carried out to confirm the thickness minimization structural condition(minimum thickness shape of leaflet).

• PNF and Movement
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• v.20 no.1
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• pp.1-8
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• 2022

Purpose: The purpose of this study was to investigate the effect of blood flow restriction bridge exercise on leg muscle thickness and balance. In addition, it is to promote blood flow restriction exercise as the basis for early prevention, diagnosis, and treatment of sarcopenia in clinical practice. Methods: Twenty elderly women aged 65 years or older were selected to participate in this study. The subjects were divided into two groups of 10: one with blood flow restriction with bridge exercise (BFRG) and the other with bridge exercise alone (BG). As for the exercise method, the thickness of rectus femoris and vastus medialis and Berg balance scale were investigated by intervention for 30 minutes a day, 3 times a week, for a total of 6 weeks. Results: There was significant difference in the thickness of the rectus femoris and vastus medial and within-group changes in the Berg balance scale (p <0.05) before and after the experiment in the BFRG and BG groups (p<0.05). There was a significant difference in change between the two groups (p <0.05). Conclusion: There was a significant difference in the intragroup change of the Berg balance scale in the BFRG before and after the experiment, but there was no significant difference in the BG, and there was no significant difference in the change between the two groups.