Russian Journal of Biomechanics最新文献

An electromyography system, kinetics and kinematics variables are insufficient to predict the failure-to-recover an impending loss of balance 肌电图系统、动力学和运动学变量不足以预测即将失去平衡时的失误恢复情况

Russian Journal of Biomechanics Pub Date : 2020-03-31 DOI: 10.15593/rjbiomech/2020.1.06

M. L. Aguiar, Caluê Papcke, E. Scheeren

{"title":"An electromyography system, kinetics and kinematics variables are insufficient to predict the failure-to-recover an impending loss of balance","authors":"M. L. Aguiar, Caluê Papcke, E. Scheeren","doi":"10.15593/rjbiomech/2020.1.06","DOIUrl":"https://doi.org/10.15593/rjbiomech/2020.1.06","url":null,"abstract":"The body balance maintenance is performed through synchronized motor strategies, to preserve functional mobility. The purpose of this study is to compare the balance recovery mechanisms among young adults in an impending loss of balance. Thirty healthy young adult [age 24.87±4.16; weight 72.69±14.73 kg; growth 1.72±0.08 m] participated in the study. Seven perturbations were applied with a progressive velocity of the perturbation, in the antero-posterior direction. The following variables were analyzed: active time of muscle contraction, latency and displacement amplitude of the center of pressure, and angular variation of the ankle. For each perturbation, the subjects were classified according to their ability to recover balance: “no step” and step forward or hold the rope of the safety vest support. There were no significant differences between groups in all variables analyzed. At lower velocities of displacement, the group of “no step” presented greater angular variation for the knee joint, lower pressure center displacement range, and lower active time of normalized contraction of the muscle anterior tibial. The results suggest that the variables analyzed were insufficient to identify significant differences in the adoption of strategies for recovery of balance in an impending loss of balance.","PeriodicalId":37840,"journal":{"name":"Russian Journal of Biomechanics","volume":" 39","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141219886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

In vitro wear investigation of polyether ether ketone biopolymer for total knee replacement 用于全膝关节置换术的聚醚醚酮生物聚合物的体外磨损研究

Russian Journal of Biomechanics Pub Date : 2020-03-31 DOI: 10.15593/rjbiomech/2020.1.05

Sandeep Kumar, K.V.S. Rajeswara Rao, Sunil R. Yalamalle

{"title":"In vitro wear investigation of polyether ether ketone biopolymer for total knee replacement","authors":"Sandeep Kumar, K.V.S. Rajeswara Rao, Sunil R. Yalamalle","doi":"10.15593/rjbiomech/2020.1.05","DOIUrl":"https://doi.org/10.15593/rjbiomech/2020.1.05","url":null,"abstract":"Nowadays, the average life span of knee prosthesis used in total knee replacement is approximately 10 to 15 years. The prevention of failure for these implants has been a constant struggle for orthopaedic surgeons and engineers. The reason behind for implant failures includes wear, infection, instability and stiffness. The major causes of failure are wear and tear of prosthesis. The most common biomaterials used in total knee replacement rubbing against a mating component of ultra-high-molecular-weight polyethylene are titanium alloy Ti6AI4V and alloy CoCrMo. The main drawback is that implants are still restrained by tiny ultra-high molecular weight poly debris generated by long term friction between femoral component and polyethylene articulating surface. Hence, the attempt is made to reduce the wear rate by replacing with high wear-resisting biomaterial. This research investigated whether polyether ether ketone was the appropriate material for total knee replacement by examining wear performance against Ti6AI4V. The experiments are conducted with different loading and speeds. The results are optimized by developing the regression equation using analysis of variance.","PeriodicalId":37840,"journal":{"name":"Russian Journal of Biomechanics","volume":" 83","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141219766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Biomechanical approach to dental orthopedic treatment of patients with postoperative defect of the upper jaw 对上颌骨术后缺损患者进行牙科矫形治疗的生物力学方法

Russian Journal of Biomechanics Pub Date : 2020-03-31 DOI: 10.15593/rjbiomech/2020.1.03

Z. Shanidze, Sergey Muslov, Anatoly Arutyunov, Nataliya Astashina, Sergey Arutyunov

引用次数: 1

Optimal time task in saccadic eye movement 眼球移动中的最佳时间任务

Russian Journal of Biomechanics Pub Date : 2020-03-31 DOI: 10.15593/rjbiomech/2020.1.04

A. Kruchinina

{"title":"Optimal time task in saccadic eye movement","authors":"A. Kruchinina","doi":"10.15593/rjbiomech/2020.1.04","DOIUrl":"https://doi.org/10.15593/rjbiomech/2020.1.04","url":null,"abstract":"This article is devoted to fast goal-directed human eye movements. Such movements are described in few ways. One of them is the time-optimal problem model. It this work, the saccade – fast single conformable ballistic eye movement, is under consideration. Saccadic eye trajectory is described by time-optimal task solution. Differential equations system are based on pendulum model. It defines control moment applied from extraocular muscles to eye globe and movement of it. Main feature of the system is all values in suggested system have physical meaning and were found in published experimental investigations. Consideration of the moment applied from extraocular muscles to eye glob as control is main difference of the system from other models for eye movement in submitted works. In this case, the open-loop system has two real roots and one zero. The particular case of the ratio of real roots of 1:3 is analyzed in the article. As a result of modelling, trajectory characteristics closed to the saccades observed in experimental studies is obtained. On the basis of the constructed model, the parameters of the synthesized saccades were compared with the parameters obtained on the experimental sample. The obtained models can be used both for problems of physiology and medicine, and for constructing virtual reality environments. For example, when developing 3D interfaces, the use of a mathematical model makes it possible to optimize the elements arrangement using game theory.","PeriodicalId":37840,"journal":{"name":"Russian Journal of Biomechanics","volume":" 41","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141219686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Biaxial mechanical characterization and constitutive modelling of sheep sclera soft tissue 绵羊巩膜软组织的双轴机械特性和构成模型

Russian Journal of Biomechanics Pub Date : 2020-03-31 DOI: 10.15593/rjbiomech/2020.1.09

Zwelihle Ndlovu, F. Nemavhola, Dagwood Desai

{"title":"Biaxial mechanical characterization and constitutive modelling of sheep sclera soft tissue","authors":"Zwelihle Ndlovu, F. Nemavhola, Dagwood Desai","doi":"10.15593/rjbiomech/2020.1.09","DOIUrl":"https://doi.org/10.15593/rjbiomech/2020.1.09","url":null,"abstract":"Constant exposure to the environment, head trauma and shaking of ocular tissues result in damage and disorders of the eye. In the United States, trauma alone causes about 30 000 people each year to lose vision in one eye. The sclera soft tissue plays a vital role in protecting, maintaining the shape of the eye and regulating the intraocular pressure, and is closely linked with glaucoma. The aim of the study was to investigate and compare the mechanical response of sheep sclera soft tissue under equibiaxial tension as data from such studies are limited. The material parameters describing the mechanical behaviour were determined using the Fung and Choi–Vito models. Sheep eyes were transported in ice and tested in saline solution at a temperature 37° C using within 4 to 6 hours after slaughter. Sheep sclera tissue was found to be nonlinear and anisotropic with average anisotropy constants (A) of 0.69 and 0.74 for the Fung and Choi–Vito models, respectively. The coefficients of correlation (R2 ) between the experimental and hyperelastic models were found to be 0.98 and 0.95 respectively, with Fung model providing the best fit and more anisotropic behaviour than the Choi–Vito model.","PeriodicalId":37840,"journal":{"name":"Russian Journal of Biomechanics","volume":" 93","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141219764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Aspect ratio as a factor predicting rupture of cerebral aneurysms 纵横比是预测脑动脉瘤破裂的一个因素

Russian Journal of Biomechanics Pub Date : 2020-03-31 DOI: 10.15593/rjbiomech/2020.1.01

Dmitriy Ivanov, Aleksandr V. Dol, Leonid Kossovich

{"title":"Aspect ratio as a factor predicting rupture of cerebral aneurysms","authors":"Dmitriy Ivanov, Aleksandr V. Dol, Leonid Kossovich","doi":"10.15593/rjbiomech/2020.1.01","DOIUrl":"https://doi.org/10.15593/rjbiomech/2020.1.01","url":null,"abstract":"Cerebral vascular aneurysms are abnormalities present in 2–5% of the population. Aneurysm rupture often leads to the development of a hemorrhagic stroke. Among its consequences are disability and death. Despite this, preventive surgical treatment of aneurysms is not always justified, since it leads to serious postoperative complications. In this regard, there is the problem of developing and justifying reliable and convenient criteria for assessing the risk of aneurysm rupture. Aspect ratio (the ratio of the height of the aneurysm to the diameter of the neck) is the relative size of the aneurysms used to classify them as prone to rupture and not prone to rupture. This characteristic is also used as predictor of aneurysm rupture. In this paper, we carried out a series of numerical biomechanical calculations aimed at substantiating the critical value of the aspect ratio characterizing aneurysms prone to rupture. In the simulation, the average shear stresses on the aneurysm wall were compared for different aspect ratios from 0.5 to 2.25 with a step of 0.25 for asymmetric models and for aspect ratios from 0.5 to 2.1 with a step of 0.2 for symmetrical models. It was revealed that average wall shear stresses on the aneurysm significantly decrease when the aspect ratio is greater than critical. An abrupt decrease in the average wall shear stresses on the aneurysm with aspect ratio greater than the critical value was revealed.","PeriodicalId":37840,"journal":{"name":"Russian Journal of Biomechanics","volume":" 14","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141219753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Analysis of kinematics of the approach run in long jump event among Jordanian male team 约旦男队跳远项目接近跑运动学分析

Russian Journal of Biomechanics Pub Date : 2020-03-31 DOI: 10.15593/rjbiomech/2020.1.02

Osama Abdel Fattah, A. Bataineh

{"title":"Analysis of kinematics of the approach run in long jump event among Jordanian male team","authors":"Osama Abdel Fattah, A. Bataineh","doi":"10.15593/rjbiomech/2020.1.02","DOIUrl":"https://doi.org/10.15593/rjbiomech/2020.1.02","url":null,"abstract":"The purpose of this investigation was to study kinematic variables at the approach run and take-off phase. Furthermore, to study the relationships between these kinematic variables among Jordanian male team in long jump event. To achieve this, four elite male jumpers from the Jordanian male team (age 18±0.6 years; height 180±2 cm; mass 72±2 kg; the leg length 87±1 cm; training age 4±0.58 years) were studied. Subjects were filmed by digital video cameras (Nikon D3400, 60 fps). The first camera was placed 20 m lateral from the center of the approach run to capture the steps, vertical height of the camera was 1.2 m. The second camera was positioned to capture the last two strides and take-off phase, this camera was placed 8 m lateral from the last two stride to capture other study variables, vertical height of the camera was 1 m. The video data were performed with Kinovea analysis program (version 0.8.2764 × 64), where the best attempt was analyzed. This study involved 15 kinematic variables. According to the results obtained in this study, we can conclude that the subjects of this study show asymmetrical results in most study variables except touch-down time variable. Furthermore, one interesting finding is that a height of center of mass at take-off variable is the only one that has a statistically significant relationship with the achievement distance (r = 0.949). Finally, it is recommended the establishment of a kinetic file for each long jumpers.","PeriodicalId":37840,"journal":{"name":"Russian Journal of Biomechanics","volume":" 97","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141219654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

The problem of "gymnast" motion control in free flight and during the transition in the state of contact with the support 体操运动员 "在自由飞行和与支撑物接触状态过渡期间的运动控制问题

Russian Journal of Biomechanics Pub Date : 2020-03-31 DOI: 10.15593/rjbiomech/2020.1.07

Eduard Lavrovskii

{"title":"The problem of \"gymnast\" motion control in free flight and during the transition in the state of contact with the support","authors":"Eduard Lavrovskii","doi":"10.15593/rjbiomech/2020.1.07","DOIUrl":"https://doi.org/10.15593/rjbiomech/2020.1.07","url":null,"abstract":"The study from the position of theoretical mechanics discusses some aspects of the jump down of the \"gymnast\" – athlete (or the robot – \"gymnast\") from the \"crossbar\". We discuss all phases of the jump in the planar case. \"Gymnast\" body is modeled as three-links physical pendulum, however, after departing from the \"crossbar\" and lowering the \"hands\" model the dynamic system becomes two-links pendulum. For a two-links model in the regime of \"kinematic\" control, we deal with the process of lowering hands, free flight, the output of the \"legs\" on the frame (absolutely inelastic impact) and holding operation in support phase with the aim of vertical stabilize of the pendulum system. Mode \"kinematic control\" means the ability to instantly change the angle between the links of the body (in some limits). For each of the phases of movement, we found a convenient form of describing dynamical equations. These equations are based on the use as a variable momentum of the system relative to various points of the body or space. The order of this system of equations is lower than for the full order system. The stage of calm \"gymnast\" that occurs after the foot on the surface of the support, will also be examined on the basis of special system of equations of this type. It was shown, that we can use numerical analysis to build the region of controllability for transition of the two-links model in a state of stabilization, corresponding to the equality of the horizontal coordinate of the support foot and the center of gravity of the two-links pendulum system. The algorithm of stabilizing control is designed. The results of presented of the analysis of the problem allow us to construct a convenient approximate model of the phenomenon as a whole, and to use it to control a robotic counterpart. As an example, it is considered one of the cases of motion that corresponds to the anthropomorphic model.","PeriodicalId":37840,"journal":{"name":"Russian Journal of Biomechanics","volume":" 29","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141219661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effectiveness of Blalock–Taussig shunt performance in the congenital heart disease children 布洛克-陶西格分流术在先天性心脏病患儿中的应用效果

Russian Journal of Biomechanics Pub Date : 2020-03-31 DOI: 10.15593/rjbiomech/2020.1.08

A. Kuchumov, A. Khairulin, A. Biyanov, A. Porodikov, Vagram Aratyunyan, Yuriy Sinelnikov

{"title":"Effectiveness of Blalock–Taussig shunt performance in the congenital heart disease children","authors":"A. Kuchumov, A. Khairulin, A. Biyanov, A. Porodikov, Vagram Aratyunyan, Yuriy Sinelnikov","doi":"10.15593/rjbiomech/2020.1.08","DOIUrl":"https://doi.org/10.15593/rjbiomech/2020.1.08","url":null,"abstract":"A problem of congenital heart defects with obstruction of the right ventricle output tract is urgent because of disease severity and need for multistage surgical treatment. The first stage of surgical correction is system–pulmonary shunt installation. Nevertheless, there are controversial views on the choice of the shunt optimal diameter and the implantation place selection. Anastomosis should provide sufficient, but no excessive pulmonary blood flow without reducing cardiac output, pulmonary vessels damage, and provide uniform growth of pulmonary arteries. In this paper, the model of blood flow in \"aorta–shunt–pulmonary artery\" is considered. A set of geometric images was obtained in four patients for the further import into ANSYS CFX finite element solver to solve the hemodynamic problem. Three variants of the modified Blalock–Taussig shunt installation were analyzed with by using widely adopted hemodynamic indices (wall shear stress, time averaged wall shear stress, oscillatory shear index, relative residence time). It was shown that shunting options differ for the various patients. Moreover, flow asymmetry in the pulmonary arteries at different implantation sites was noticed. Also, a comparison of hemodynamic performance was made to assess the effectiveness of the modified Blalock– Taussig shunt. An objectivized and personalized approach to specific treatment of each patient will significantly reduce child mortality and improve the quality of rehabilitation.","PeriodicalId":37840,"journal":{"name":"Russian Journal of Biomechanics","volume":" 28","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141219906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3