Analysis of the Relationship between Femoral Head Center Position and Mechanical Parameters during Walking

2017 ◽  
Vol 2017 (0) ◽  
pp. J2320101
Author(s):  
Yuma OSAWA ◽  
Jonas Aditya PRAMUDITA ◽  
Hayato SUZUKI ◽  
Dai MIYASAKA ◽  
Yuji TANABE
2011 ◽  
Vol 41 (1) ◽  
pp. 86-93 ◽  
Author(s):  
Samuel P. Franklin ◽  
Ashley L. Franklin ◽  
Howard Wilson ◽  
Loren Schultz ◽  
B. Sonny Bal ◽  
...  

2011 ◽  
Vol 48-49 ◽  
pp. 1235-1240
Author(s):  
Zhen Ying Zhang ◽  
Da Zhi Wu

By theoretical analysis and laboratory test, the model parameters of Duncan-Chang for municipal solid waste have been studied. To obtain the mechanical parameters, a new simple and practical method has been established. Research results show that the damage ratio is 0.6, parameter n is about 1.05, parameter F varies between 0 and 0.1, and parameter G varies between 0.3 and 0.4. Besides, the relationship between parameter k and the initial void ratio is linear, and the slope of the line is 5.0.


2017 ◽  
Vol 865 ◽  
pp. 366-372
Author(s):  
Jing Sen Liu ◽  
Hai Bo Li ◽  
Guo Kai Zhang ◽  
Jian Deng

In order to improve the accuracy of the rock mechanical parameters, the correlations among physical and mechanical parameters were investigated. A large number of laboratory testing results curried out on 408 rock specimens including metamorphic rocks, sedimentary rocks and igneous rocks. Through the statistical analysis of the laboratory test data, several regression equations among rock material parameters were established. The research suggests that, in addition to Poisson's ratio, the mechanical parameters (unconfined compressive strength (UCS), elastic Young’s modulus, shear modulus) relate well to physical parameters (porosity, P-wave velocity), and the relationships are mainly described by power and exponential correlations which have good squared regression coefficients. The correlation between elastic Young’s modulus and dynamic elastic modulus was established, as well as the relationship between shear modulus and dynamic shear modulus.


2015 ◽  
Vol 645-646 ◽  
pp. 926-930 ◽  
Author(s):  
Shuang Shi Yuan ◽  
Guang He ◽  
Ming Zhang ◽  
Guo Zhong Li

MEMS nickel material is commonly used for structural material in micro devices. In order to study the effect of environmental temperature on its mechanical properties,this paper has built up a experimental system which can measure the temperature-related static mechanical parameters of the UV-LIGA nickel material. By using the system for uniaxial tensile experiments of the micro specimen under different temperature, the stress-strain curves of the micro specimen under different temperature were obtained; the mechanical parameters of the micro specimen such as elastic modulus, yield stress and failure stress under different temperature were also calculated out;Finally, the relationship between temperature and mechanical parameters including elastic modulus, yield stress and failure stress was analyzed.


2021 ◽  
Author(s):  
Tingting Liu ◽  
Yuju Cao ◽  
Changxu Han ◽  
Feimeng An ◽  
Tiantian Wang ◽  
...  

Abstract IntroductionSteroid-induced osteonecrosis of the femoral head (ONFH ) is a disease of bone metabolism, and genetic factors are generally considered to play an important role. The purpose of this study was to investigate the relationship between single nucleotide polymorphisms (SNPs) in MIR17HG and MIR155HG and the risk of steroid-induced ONFH in the population of northern China.MethodsA total of 199 steroid-induced ONFH patients and 506 healthy controls were recruited for the study. Four SNPs of MIR17HG and seven SNPs of MIR155HG were genotyped by Sequenom MassARRAY. ORs and 95% CIs were used to evaluate the relationship between these SNPs and steroid-induced ONFH.ResultsIn the codominant model, patients with the MIR17HG SNPs(rs7318578) AA genotype had an increased risk of steroid-induced ONFH (OR = 1.79, p = 0.039), in the recessive model, patients with the MIR17HG SNP(rs7318578) AA genotype had an increased risk of steroid-induced ONFH (OR = 1.78, p = 0.032). Stratified analysis showed that a MIR17HG SNP (rs7318578) and MIR155HG SNPs(rs77218221, rs11911469, rs34904192 and rs4143370) were closely related to different unornamented phenotypes of steroid-induced ONFH. Analysis of the clinical indicators revealed significant differences in high-density lipoprotein (HDL-C) levels between the ONFH group and the control group (p = 0.005). MIR17HG SNP(rs75267932) and MIR155HG SNPs(rs77699734, rs1893650 and rs34904192) were correlated with different lipid indexes.ConclusionOur results confirm that MIR17HG and MIR155HG gene mutations are associated with steroid-induced ONFH susceptibility in the population of northern China, providing new evidence for the early detection and prevention of ONFH.


2021 ◽  
Author(s):  
Hao-Hua Wu ◽  
Dean Chou ◽  
Kevork Hindoyan ◽  
Jeremy Guinn ◽  
Joshua Rivera ◽  
...  

Abstract Introduction Although matching lumbar lordosis (LL) with pelvic incidence (PI) is an important surgical goal for adult spinal deformity (ASD), there is concern that overcorrection may lead to proximal junctional kyphosis (PJK). We introduce the upper instrumented vertebra–femoral angle (UIVFA) as a measure of appropriate postoperative position in the setting of lower thoracic to pelvis surgical correction for patients with sagittal imbalance. We hypothesize that a more posterior UIV position in relation to the center of the femoral head is associated with an increased risk of PJK given compensatory hyperkyphosis above the UIV. Methods In this retrospective cohort study, adult patients undergoing lower thoracic (T9–T12) to pelvis correction of ASD with a minimum of 2-year follow-up were included. UIVFA was measured as the angle subtended by a line from the UIV centroid to the femoral head center to the vertical axis. Patients who developed PJK and those who did not were compared with preoperative and postoperative UIVFA as well as change between postoperative and preoperative UIVFA (deltaUIVFA). Results Of 119 patients included with an average 3.6-year follow-up, 51 (42.9%) had PJK and 24 (20.2%) had PJF. Patients with PJK had significantly higher postoperative UIVFA (12.6 ± 4.8° vs. 9.4 ± 6.6°, p = 0.04), deltaUIVFA (6.1 ± 7.6° vs. 2.1 ± 5.6°, p < 0.01), postoperative pelvic tilt (27.3 ± 9.2 vs. 23.3 ± 11, p = 0.04), postoperative lumbar lordosis (47.7 ± 13.9° vs. 42.4 ± 13.1, p = 0.04) and postoperative thoracic kyphosis (44.9 ± 13.2 vs. 31.6 ± 18.8) than patients without PJK. With multivariate logistic regression, postoperative UIVFA and deltaUIVFA were found to be independent risk factors for PJK (p < 0.05). DeltaUIVFA was found to be an independent risk factor for PJF (p < 0.05). A receiver operating characteristic (ROC) curve for UIVFA as a predictor for PJK was established with an area under the curve of 0.67 (95% CI 0.59–0.76). Per the Youden index, the optimal UIVFA cut-off value is 11.5 degrees. Conclusion The more posterior the UIV is from the femoral head center after lower thoracic to pelvis surgical correction for ASD, the more patients are at risk for PJK. The greater the magnitude of posterior translation of the UIV from the femoral head center from preop to postop, the greater the likelihood for PJF.


2020 ◽  
Author(s):  
Tiantian Wang ◽  
Huiqiang Wu ◽  
Tingting Liu ◽  
Mneghu Sun ◽  
Feimeng An ◽  
...  

Abstract Background: Steroid-induced osteonecrosis of the femoral head (ONFH) is aseptic necrosis of the femoral head caused by glucocorticoid use. Once necrotic femoral head necrosis occurs, it irreversibly affects the quality of life seriously. Studies have shown that the susceptibility to steroid-induced ONFH is likely to be related to the variation of miRNA coding genes. Therefore, this study aimed was to investigate the effect of MIR3142HG on steroid-induced ONFH.Methods: Agena MassARRAY was used to genotype MIR3142HG gene rs1582417, rs2431689, rs7727155 and rs17057846 in 199 patients and 506 healthy people. A genetic model and haplotype analysis were used to evaluate the relationship between the MIR3142HG polymorphism and the risk of steroid-induced ONFH. The odds ratio (OR) and 95% confidence intervals (CIs) were obtained through logistic regression to assess the influence of gene polymorphisms on the occurrence of steroid-induced ONFH.Results: The consequences show that rs7727115(OR=0.76,p=0.036) is a protective factor, it could reduce the risk of steroid-induced ONFH, rs1582417(OR=1.28, p=0.041) could increase the risk of steroid-induced ONFH. Stratified analysis , according to each clinical index shows that MIR3142HG TC-CC genotype facilitated the risk of steroid-induced ONFH in male ( p<0.05). In addition, rs2431689 is related to HDL-C(p=0.012) and ApoA1 (p=0.010) levels, and rs17057846 (p=0.024) is related to ApoB levels.The linkage analysis indicated that three SNPs (rs2431689, rs7727115 and rs17057846) in MIR3142HG with significant chain imbalance. In addition, haplotype “GGG” of MIR3142HG was found out is harmful for steroid-induced ONFH.Conclusion: Our results firstly confirm that the genetic polymorphism of MIR3142HG is associated with steroid-induced ONFH susceptibility in Chinese Han population.


Author(s):  
Г.Д. КОКОРЕВ ◽  
Е.А. ЖУРАВЛЕВА

В исследовании рассмотрены некоторые составляющие технической эксплуатации автомобильной техники (АТ), связанные с диагностированием топливной аппаратуры двигателей внутреннего сгорания (ДВС), причем с целью осуществления неразрушающего контроля предлагается применять ультразвуковую и акустико-эмиссионную системы технического диагностирования.Необходимо констатировать, что при рассмотрении соотношений, показывающих взаимосвязь акустических и физико-механических параметров материалов, в основном используется временной интервал, и при его некорректном измерении получаем низкую информативность и невысокую точность акустических методов определения механических характеристик. При разработке методики использованы принципы спектрального анализа импульсов, отраженных от исследуемых элементов АТ, на которых опирается также метод разработки как аппаратного так и программного обеспечения для обработки полученных сигналов. Результаты предыдущих исследований дают основание полагать, что применение преобразований Фурье обеспечивает получение достоверной информации, основанной на акустических сигналах, если последовательность измерений составляет около 10 секунд. Опыт разработчиков системы свидетельствует о высокой информативности параметров распространения рэлеевских волн. В связи с этим система была укомплектована специально разработанным малобазным датчиком рэлеевских волн. Регистрированные отраженные сигналы в последующем обрабатываются пакетом прикладных программ. Данный преобразователь может быть эффективно использован в задачах контроля накопления повреждений в материале элементов АТ, подвергаемых упруго-пластическим и усталостным воздействиям.Принцип действия системы основан на стробоскопическом эффекте восстановления отраженных импульсов, которые получаются в результате «облучения» материала обследуемого элемента АТ зондирующими импульсами в указанной полосе частот. The study considers some components of technical operation of automotive equipment (at) related to the diagnosis of fuel equipment of internal combustion engines, and for the purpose of non-destructive testing, it is proposed to use ultrasonic and acoustic emission systems for technical diagnostics. It should be noted that when considering the relations showing the relationship between acoustic and physical-mechanical parameters of materials, the time interval is mainly measured, and if the measurement is incorrect, the relationship between the acoustic and physical-mechanical parameters of the material often gives low information content and low accuracy of acoustic methods for determining mechanical characteristics. When developing the technique, the principles of spectral analysis of pulses refl ected from the studied at elements are used, which also support the method of developing both hardware and software for processing the received signals. The results of previous studies suggest that the use of Fourier transforms provides reliable information based on acoustic signals, if the measurement sequence is about 10 seconds. The experience of the system developers shows that the parameters of Rayleigh wave propagation are highly informative. In this regard, the system was equipped with a specially developed low-base relay wave sensor. The registration of refl ected signals is then processed by a package of application programs. This Converter can be effectively used in the tasks of monitoring the accumulation of damage in the material of at elements subjected to elastic-plastic and fatigue effects. The principle of operation of the system is based on the stroboscopic effect of recovery of refl ected pulses, which are obtained as a result of "irradiation" of the material being examined by the at element with probing pulses in the specifi ed frequency band.


2012 ◽  
Vol 256-259 ◽  
pp. 207-210
Author(s):  
Chun Lai Qu ◽  
Ke Jiang ◽  
Min Xue ◽  
Zhao Cai Zhang

The mechanics parameters of a slope are difficult to determine accurately by conventional methods, because of weathering, fracture and excavation induced stress release. Based on the orthogonal test and three-dimensional numerical calculation to get the learning samples of displacement, By using the neural network method to obtain the relationship between the mechanical parameters and displacement, Combined with measurement results of deformation in the field mining, Obtained the reasonable strata parameters to provide the basis for slope treatment.


Sign in / Sign up

Export Citation Format

Share Document