• The Journal of Korean Physical Therapy
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• 제31권2호
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• pp.82-87
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• 2019

Purpose: The purpose of this study was to examine the effects of plank exercises with resistance of one-sided hip adduction on abdominal muscle thickness. Methods: Thirty subjects were divided into a group that underwent plank exercises with one-sided hip adduction resistance (n=15) and a group that underwent plank exercises only (n=15). Their changes in abdominal muscle thickness before the experiment (n=15) and three and six weeks after the experiment were analyzed using a two-way repeated analysis of variance at a statistical significance level of ${\alpha}=0.05$. When there was any interaction between the time of measurement and each group, post hoc t-tests were conducted at a statistical significance level of ${\alpha}=0.01$. Results: The results of the experiment showed statistically significant differences in the thickness of the rectus abdominis, internal oblique muscle, and transversus abdominis, depending on the time of measurement and the interaction between the time of measurement and each group (p<0.05). Statistically significant differences were observed in the thickness of the external oblique, depending on the time of measurement, the interaction between the time of measurement and each group, and variances between the groups (p<0.05). Conclusion: The results of this study indicated that plank exercises with resistance of one-sided adduction are effective for increasing abdominal muscle thickness. The study's overall findings will likely be used as basic data for lumbar stabilization exercises and rehabilitation treatment.

• Journal of Korean Dental Science
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• 제13권2호
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• pp.59-66
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• 2020

Purpose: The purpose of this study was to investigate the masseter muscle thickness before and after treatment using ultrasound sonography in patients with parafunctional habits. Materials and Methods: From September 2019 to March 2020, a total of 27 patients who visited the Department of Oral and Maxillofacial Surgery at Ewha Womans University Seoul Hospital were collected. The thickness of both masseter muscles was measured using a tablet ultrasound scanner. Statistical analysis was performed by using the IBM SPSS version 26.0 statistical package (IBM Corp) with significance level at 0.05. Result: According to the statistical results, the thickness of the masseter muscle was thicker on the right side than on the left, with no correlation with sex or age. The severity and duration of pain did not have a significant correlation with the thickness of the masseter muscle. Botulinum A toxin injection in the masseter muscle was the most effective way to reduce pain and reduce the thickness of the masseter muscle. Splint treatment also showed some effects in reducing the thickness of the masseter muscle. Conclusion: Based on the findings, it can be claimed that ultrasonography is simple, inexpensive and easily repeatable method to get real-time diagnosis and treatment results for masseter muscles.

• PNF and Movement
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• 제18권3호
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• pp.425-433
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• 2020

Purpose: The purpose of this study was to investigate the effect of 7Hz vibration on the thickness of the rectus femoris, medial femur, rectus femoris tendon, and Achilles tendon. Methods: The statistical methods before and after working around the average value of each of the legs included repeated measures ANOVA. The subjects were 26 males residing in the N area, and we measured the change in muscle thickness and tendon thickness before, four weeks, and eight weeks after the experiment in two groups of 13 subjects each. The analysis method was a two-way repeated measurement variance analysis (ANOVA) with a significance level of 0.05 Results: The rectus femoris, medial broad muscle, rectus femur, and Achilles tendon showed significant increases in the interaction between the periods as well as between the periods and groups (p < 0.05). Conclusion: As a result of this study, the 7Hz vibration had a positive effect on the thickness of the rectus femoris and the vastus medialis muscle as well as the thickness of the rectus femoris tendon and Achilles tendon. It is expected to be used as basic data for vibrational exercises in the future studies and is expected to be used as an exercise to strengthen the leg muscles and tendons.

• 대한물리치료과학회지
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• 제29권2호
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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.

• Physical Therapy Rehabilitation Science
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• 제10권4호
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• pp.444-449
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• 2021

Objective: The purpose of this study is to observe the change in the thickness of abdominal muscles when electrical muscle stimulation (EMS) is applied to the abdomen during rest and abdominal muscle exercise to investigate the effect of EMS applied to the abdomen on the superficial and deep muscles thickness. Design: Cross sectional design. Methods: Twenty healthy subjects participated in this study. Subjects were performed resting position, resting position with EMS, curl-up and curl-up with EMS. The electrode of the EMS belt is attached to the abdominal wall between the 12th rib and iliac crest. The thickness of abdominal muscles including rectus abdominis (RA), external oblique (EO), internal oblique (IO), and transverse abdominis (TrA) were captured in each position by ultrasound image during expiration. All subjects were performed four positions randomly. Data were analyzed using repeated ANOVA with the level of significance set at 𝛼=0.05. Results: The muscle thickness of RA, EO, IO and TrA were significantly different at each position (p<0.05). The thickness of all abdominal muscles increased significantly when curl-up than curl-up with EMS. Both RA and EO thickness were significantly increased at resting position than resting position and EMS were combined(p<0.05). But IO and TrA thickness were decreased at resting position when EMS were combined. Conclusions: The results suggest that EMS activates superficial abdominal muscles RA and EO. Therefore, abdominal strengthening exercise combined EMS can activate abdominal muscles and can be applied to various patients and rehabilitation in clinical practice.

• Steel and Composite Structures
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• 제45권6호
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• pp.775-796
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• 2022

In this study, a new type of energy absorbers with a functionally graded thickness is investigated, these type of absorbers absorb energy through expanding-folding processes. The expanding-folding absorbers are composed of two sections: a thin-walled aluminum matrix and a thin-walled steel mandrel. Previous studies have shown higher efficiency of the mentioned absorbers compared to the conventional ones. In this study, the effect of thickness which has been functionally-graded on the aluminum matrix (in which expansion occurs) was investigated. To this end, initial functions were considered for the matrix thickness, which was ascending/descending along the axis. The study was done experimentally and numerically. Comparing the experimental data with the numerical results showed high consistency between the numerical and experimental results. In the final section of this study, the best energy absorber functionally graded thickness was introduced by optimization using a third-order genetic algorithm. The optimization results showed that by choosing a minimum thickness of 1.6 mm and the exponential coefficient of 3.25, the most optimal condition can be obtained for descending thickness absorbers.

• Computers and Concrete
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• 제31권1호
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• pp.71-84
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• 2023

In this paper, the effects of the thickness of cubic samples on the tensile strength of concrete blocks were studied using experimental tests in the laboratory and numerical simulation by the particle flow code in three dimensions (PFC3D). Firstly, the physical concrete blocks with dimensions of 150 mm×190 mm (width×height) were prepared. Then, three specimens for each of seven different samples with various thicknesses were built in the laboratory. Simultaneously with the experimental tests, their numerical simulations were performed with PFC3D models. The widths, heights, and thicknesses of the numerical models were the same as those of the experimental samples. These samples were tested with a new tensile testing apparatus. The loading rate was kept at 1 kg/sec during the testing operation. Based on these analyses, it is concluded that when the thickness was less than 5 cm, the tensile strength decreased by increasing the sample thickness. On the other hand, the tensile strength was nearly constant when the sample thickness was raised to more than 5 cm (which can be regarded as a threshold limit for the specimens' thickness). The numerical outputs were similar to the experimental results, demonstrating the validity of the present analyses.

• Journal of Community Nutrition
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• 제2권2호
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• pp.129-134
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• 2000

The purpose of the present study is to evaluate the validity of the BMI as an indicator of obesity for Koreans. The usefulness of the BMI to represent overweight and obesity was evaluated by measuring the relative validity of sensitivity and specificity, and was compared with the validity of triceps skinfold thickness(mm). To measure the relative validity of the BMI and triceps skinfold thickness, body fat(%) was used as a reference measure of obesity. The study population included 844 participants aged 20-69 years who resided in Kuri City in Kyunggi province. Participants were measured regarding weight, height, triceps skinfold thickness and body fat. The prevalence of obesity for male subjects was 32.0%, 66.2%, and 0.9%, and for female subjects, 17.6%, 56.1%, 12.4% based on the BMI, triceps skinfold thickness, and body fat(%) respectively. The prevalence of obesity was higher based on the BMI or triceps skinfold thickness than body fat measurement. The sensitivity and specificity of the BMI were 33.3% and 67.9% in male subjects and 77.7% and 90.8% in female subjects. Sensitivity of the BMI was lower, and specificity was higher than those of triceps skinfold thickness. In summary, BMI as an indicator of obesity for Korean showed a tendency of overestimation of obesity prevalence. Therefore, there is a need to develop a more reliable obesity index other than the BMI for Koreans.

• 한국전기전자재료학회논문지
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• 제36권2호
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• pp.129-135
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• 2023

An analytical threshold voltage model is presented to observe the change in threshold voltage shift ΔV_th of a junctionless double gate MOSFET using ferroelectric-metal-SiO₂ as a gate oxide film. The negative capacitance transistors using ferroelectric have the characteristics of increasing on-current and lowering off-current. The change in the threshold voltage of the transistor affects the power dissipation. Therefore, the change in the threshold voltage as a function of theferroelectric thickness is analyzed. The presented threshold voltage model is in a good agreement with the results of TCAD. As a results of our analysis using this analytical threshold voltage model, the change in the threshold voltage with respect to the change in the ferroelectric thickness showed that the threshold voltage increased with the increase of the absolute value of charges in the employed ferroelectric. This suggests that it is possible to obtain an optimum ferroelectric thickness at which the threshold voltage shift becomes 0 V by the voltage across the ferroelectric even when the channel length is reduced. It was also found that the ferroelectric thickness increased as the silicon thickness increased when the channel length was less than 30 nm, but the ferroelectric thickness decreased as the silicon thickness increased when the channel length was 30 nm or more in order to satisfy ΔV_th=0.

• PNF and Movement
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• 제20권1호
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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.