• Title/Summary/Keyword: cross-sectional area

Search Result 1,268, Processing Time 0.023 seconds

Effects of lumbar stabilization exercise on multifidus muscle cross-sectional area, static posture control and pain in patient's with chronic low back pain (요부 안정화운동이 만성요통환자의 다열근 단면적, 정적자세조절, 통증에 미치는 영향)

  • Kim, Deahun
    • Journal of Convergence for Information Technology
    • /
    • v.11 no.10
    • /
    • pp.223-229
    • /
    • 2021
  • This study analyzed the effects of an exercise program that combined lumbar stabilization exercise and muscle strengthening exercise and an exercise program that applied only lumbar muscle strengthening exercise on multifidus muscle cross-sectional area, static posture control ability, and low back pain in patients with CLBP. For the study method, 28 patients with CLBP were divided into two exercise propram groups and exercised three times a week for 8-weeks. The data analysis of this study used the t-test to compare before and after group exercise program application, and between each group (p<.05). As a result of the study, significant results were found before and after application of the exercise program within each group, such as multifidus muscle cross-sectional area, static posture control ability, and low back pain (p<.05). Between each group, the exercise program that combined lumbar stabilization exercise and muscle strengthening exercise was found to be more effective (p<.05). In conclusion, it was found that the exercise program with additional lumbar stabilization exercise improved the structure and function of various lumbar vertebrae and reduced lumbar pain.

The role of the iliotibial band cross-sectional area as a morphological parameter of the iliotibial band friction syndrome: a retrospective pilot study

  • Park, Jiyeon;Cho, Hyung Rae;Kang, Keum Nae;Choi, Kun Woong;Choi, Young Soon;Jeong, Hye-Won;Yi, Jungmin;Kim, Young Uk
    • The Korean Journal of Pain
    • /
    • v.34 no.2
    • /
    • pp.229-233
    • /
    • 2021
  • Background: Iliotibial band friction syndrome (ITBFS) is a common disorder of the lateral knee. Previous research has reported that the iliotibial band (ITB) thickness (ITBT) is correlated with ITBFS, and ITBT has been considered to be a key morphologic parameter of ITBFS. However, the thickness is different from inflammatory hypertrophy. Thus, we made the ITB cross-sectional area (ITBCSA) a new morphological parameter to assess ITBFS. Methods: Forty-three patients with ITBFS group and from 43 normal group who underwent T1W magnetic resonance imaging were enrolled. The ITBCSA was measured as the cross-sectional area of the ITB that was most hypertrophied in the magnetic resonance axial images. The ITBT was measured as the thickest site of ITB. Results: The mean ITBCSA was 25.24 ± 6.59 ㎟ in the normal group and 38.75 ± 9.11 ㎟ in the ITBFS group. The mean ITBT was 1.94 ± 0.41 mm in the normal group and 2.62 ± 0.46 mm in the ITBFS group. Patients in ITBFS group had significantly higher ITBCSA (P < 0.001) and ITBT (P < 0.001) than the normal group. A receiver operator characteristic curve analysis demonstrated that the best cut-off value of the ITBT was 2.29 mm, with 76.7% sensitivity, 79.1% specificity, and area under the curve (AUC) 0.88. The optimal cut-off score of the ITBCSA was 30.66 ㎟, with 79.1% sensitivity, 79.1% specificity, and AUC 0.87. Conclusions: ITBCSA is a new and sensitive morphological parameter for diagnosing ITBFS, and may even be more accurate than ITBT.

A Study on the Uncertainty of Structural Cross-Sectional Area Estimate by using Interval Method for Allowable Stress Design

  • Lee, Dongkyuc;Park, Sungsoo;Shin, Soomi
    • Architectural research
    • /
    • v.9 no.1
    • /
    • pp.31-37
    • /
    • 2007
  • This study presents the so-called Modified Allowable Stress Design (MASD) method for structural designs. The objective of this study is to qualitatively estimate uncertainties of tensile steel member's cross-sectional structural designs and find the optimal resulting design which can resist all uncertainty cases. The design parameters are assumed to be interval associated with lower and upper bounds and consequently interval methods are implemented to non-stochastically produce design results including the structural uncertainties. By seeking optimal uncertainty combinations among interval parameters, engineers can qualitatively describe uncertain design solutions which were not considered in conventional structural designs. Under the assumption that structures have basically uncertainties like displacement responses, the safety range of resulting designs is represented by lower and upper bounds depending on given tolerance error and structural parameters. As a numerical example uncertain cross-sectional areas of members that can resist applied loads are investigated and it demonstrates that the present design method is superior to conventional allowable stress designs (ASD) with respect to a reliably structural safety as well as an economical material.

Three-Dimensional Analysis of the Shapes of Gathered Skirts (개더스커트 형상프로포션의 3차원적 해석)

  • Lee, Myung-Hee;Jung, Hee-Kyeong
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.30 no.11 s.158
    • /
    • pp.1598-1607
    • /
    • 2006
  • The purpose of this study was to analyze the proportion of gathered skirts using a three-dimensional measurement system. And in this experiment, we have attempted to accumulate three-dimensional data of wearing model and find out adequate methods for analyzing shape of clothes. The experimental design consists of two factorial designs. We established three different kinds of fabrics, ratio of gathers. The measurement tool for three-dimensional model was whole body 3D scanner(Exima-WBS2H). Analysis program used in experiment is RapidForm 2004 PP1 and Pattern Design 2000. Data analysis utilizes SPSS WIN 10.0 Package. As the results show, there were different effect of gather and proportion of shapes among the measurements of width, thickness and areas made by different lines of vision in cross-sectional silhouette. And there were difference shapes of section area at each part of gathered skirts between vertical-outline silhouette and vortical-plane silhouette made by gathering conditions. And also the cross-sectional silhouettes and vertical silhouettes were related to shape of clothes.

Muscle Fiber Characteristics and Their Relationship to Water Holding Capacity of Longissimus dorsi Muscle in Brahman and Charolais Crossbred Bulls

  • Waritthitham, A.;Lambertz, C.;Langholz, H.-J.;Wicke, M.;Gauly, M.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.23 no.5
    • /
    • pp.665-671
    • /
    • 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.

Prevalence of chronic pain and contributing factors: a cross-sectional population-based study among 2,379 Iranian adolescents

  • Maryam Shaygan;Azita Jaberi;Marziehsadat Razavizadegan;Zainab Shayegan
    • The Korean Journal of Pain
    • /
    • v.36 no.2
    • /
    • pp.230-241
    • /
    • 2023
  • Background: This study aimed to determine the prevalence of chronic pain and its contributing factors among teenagers aged 12-21 years in Shiraz, Iran. Methods: This cross-sectional study was conducted on adolescents aged 12-21 years. Demographic variables of the adolescents and their parents as well as the pain characteristics were assessed. Descriptive statistics, multinomial logistic regression, and regression models were used to describe the characteristics of the pain and its predictive factors. Results: The prevalence of chronic pain was 23.7%. The results revealed no significant difference between the male and female participants regarding the pain characteristics, except for the home medications used for pain relief. The results of a chi-square test showed that the mother's pain, education, and occupation, and the father's education were associated significantly with chronic pain in adolescents (P < 0.05). Multinomial logistic regression also showed the mother's history of pain played a significant role in the incidence of adolescents' chronic pain. Conclusions: The prevalence of chronic pain was relatively high in these adolescents. The results also provided basic and essential information about the contributing factors in this area. However, consideration of factors such as anxiety, depression, school problems, sleep, and physical activity are suggested in future longitudinal studies.

An Observational Study on the Morphological Changes of the External Ear Canal by Converging DICOM Imaging and Design Modeling (DICOM 영상과 설계 모델링을 융합한 외이도의 형태적 변화 관찰 연구)

  • Kim, Hyeong-Gyun
    • Journal of the Korea Convergence Society
    • /
    • v.10 no.11
    • /
    • pp.173-179
    • /
    • 2019
  • DICOM(Digital Imaging and Communications in Medicine) imaging plays a significant role in the diagnosis and treatment of the human body, and design modeling is a technology of planning shapes in three dimensions according to the purpose. In this study, we converge these two technologies to observe the relationships of the cross-section, volume, and surface area to the morphological changes of the external ear canal. The experiment applied medical imaging technologies to acquire sections of the human body to create and divide centerlines using 3D shapes extracted from 19 external ear canals by applying stereolithography and 3-matic program. The results showed that the cross-sectional structure of the external ear canal had various shapes, such as oval (38.5%), semicircular (28.2%), mixed (17.9%), square (10.2%), and wrinkled (5.1%). In addition, the cross-sectional area of each phase increased as the length of the external ear canal increased, and the volume and surface area decreased towards the direction of the eardrum. However, the surface area reduction rate was relatively low. This indicates that the structure becomes irregular towards the direction of the eardrum.

Development of a Design System for a Cable Tray (케이블 트레이 설계시스템 개발)

  • Choi, Du-Soon;Choi, WooSeok
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.16 no.4
    • /
    • pp.89-96
    • /
    • 2017
  • A cable tray is a structure made of metal or a non-combustible material that supports cables in the electrical wiring of buildings. Cable trays should be developed to meet the various requirements of the construction site. In this study, a design system was developed to calculate the maximum support load and the maximum deflection according to the cross-sectional shape of the cable tray. The cross-sections of cable trays were modeled by combining linear and arc elements, and cross-sectional characteristics such as the 2nd moment of area were calculated. The distributed load and the concentrated load were applied to the cable tray using the Euler beam theory, and then the deflection profiles and maximum stress were calculated. To verify the developed system, deflection distributions and maximum stresses for two types of cable trays were calculated and compared. The maximum deflection and maximum stress errors calculated from the developed system were found to be less than 4% compared with numerical analysis results.

A Study on Optimum design of Corrugated web girder using Eurocode (유로코드를 이용한 주름웨브보의 최적설계 연구)

  • Shon, Su-Deok;Yoo, Mi-Na;Lee, Seung-Jae
    • Journal of Korean Association for Spatial Structures
    • /
    • v.12 no.4
    • /
    • pp.47-56
    • /
    • 2012
  • This paper describes the structural design and optimization of sinusoidally corrugated web girder by using EUROCODE (EN 1993-1-5). The optimum design methodology and characteristics of the optimal cross-section are discussed. We investigate a shear buckling and the concerned standards for corrugated web and explain the equations to obtain a critical stress according to buckling type. In order to perform optimization, we consider an objective function as minimum weight of the girder and use the constraint functions as slenderness ratio and stresses of flanges as well as corrugated web and deflection. Genetic Algorithm is adopted to search a global optimum solution for this mathematical model. For numerical example, the clamped girder under the concentrated load is considered, while the optimum cross-sectional area and design variables are analyzed. From the results of the adopted example, the optimum design program of the sinusoidally corrugated web girder is able to find the suitable solution which satisfied a condition subject to constraint functions. The optimum design shows the tendency to decrease the cross-sectional area with the yielding strength increase and increase the areas with load increase. Moreover, the corrugated web thickness shows a stable increase concerning the load.

Development of Drift Design Method for High-rise Buildings Considering Characteristics of Member Forces (부재력 특성을 고려한 설계변수를 사용한 고층건물 변위조절설계법 개발)

  • 서지현;박효선
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.17 no.2
    • /
    • pp.215-222
    • /
    • 2004
  • Drift design methods using resizing techniques have been presented as a practical drift control methods of high-rise buildings. Most drift design methods using the resizing techniques have adopted the cross-sectional area as the design variables for all structural members in a structure. However, the cross-sectional area is not always governing sectional property for the structural members, but the governing sectional property of each member is dependent on the characteristics of member forces. In this paper, a drift design method using the sectional property related to the governing displacement participation factor as the design variable of each member is presented and applied to the drift design of 20-story steel frame-shear wall system. It can be noted from example test that drift design method considering member characteristics shows similar or somewhat better results in the view point of structural weights and the accuracy of displacement estimation.