scholarly journals Distal interosseous membrane of the forearm: anatomy, biomechanics, diagnostics

2020 ◽  
Vol 27 (4) ◽  
pp. 65-72
Author(s):  
Igor O. Golubev ◽  
Natalia Yu. Matveeva ◽  
Mikhail L. Maksarov
Keyword(s):  
Elbow Joint ◽  
Anatomical Study ◽  
Upper Extremities ◽  
Interosseous Membrane ◽  
Functional Study ◽  
Instrumental Method ◽  
Passive Rotation ◽  
The Stability ◽  
Connective Tissue Structure ◽  
Number Of Authors

Relevance. Recent studies show that even with damage to the structures of the triangular fibrocartilaginous complex (primary stabilizer), instability of the distal ray-elbow joint does not develop in some cases. Studies carried out by a number of authors prove that the distal interosseous membrane of the forearm can influence the stability of the joint and be a secondary stabilizer for it. Aim of the study. To study the variability in the structure of the distal interosseous membrane of the forearm using anatomical material and determine the effect of the distal interosseous membrane on the stability of the distal ray-elbow joint. Using ultrasound to determine the variability of the structure of the distal interosseous membrane of the forearm. Materials and methods. Material for our study was 10 pairs of anatomical specimens of the upper extremities. The functional viability was assessed by passive rotation of the anatomical material of the forearm. Changes in the tension of the distal interosseous membrane, its additional formations and the capsule of the distal ray-elbow joint were observed. Ultrasound was chosen as an instrumental method for visualizing the distal interosseous membrane of the forearm and its structures. In the course of this work, 30 volunteers of both sexes and different ages were examined. The study was carried out: maximum pronation (position of the sensor back) and maximum supination (position of the sensor palmar). Results. In the course of the anatomical study, we determined that in 6 pairs of anatomical material, the distal interosseous membrane is a thin transparent connective tissue structure. No additional formations in the form of thickening were found. In 4 pairs of preparations, which amounted to 40% of the total amount in the distal interosseous membrane, there were additional formations in the form of thickening of the membrane this is the distal oblique bundle and the distal ray-the ulnar tract. During the functional study, it was revealed that during pronation of the forearm, the distal membrane and dorsal capsule are stretched, which in turn holds the head of the ulna in the sigmoid notch of the radius. After conducting ultrasound, we determined the variability in the structure of the distal interosseous membrane of the forearm. The distal oblique bundle is visualized as a linear hyperechoic formation. Of the 30 surveyed, this formation was identified in 13 women (92.8%) and 1 man (7.1%), which in percentage terms was 43%. Conclusion. After conducting anatomical examination, we determined the variability in the structure of the distal interosseous membrane of the forearm in the form of the presence of thickenings the distal oblique bundle and the distal ray-ulnar tract, and determined the effect of these structures on the stability of the distal ray-elbow joint. An ultrasound scan also identified the features in the structure of the distal interosseous membrane in the form of hyperechoic formation.

A DENSITY FUNCTIONAL STUDY OF THE STRUCTURE OF SILANE COUPLING AGENT 3–AMINOPROPYLTRIETHOXYSILANE

2005 ◽  
Vol 04 (01) ◽  
pp. 117-126
Author(s):  
N. L. MA ◽  
P. WU
Keyword(s):  
Coupling Agent ◽  
Density Functional ◽  
Solution Structure ◽  
Silane Coupling Agent ◽  
Industrial Applications ◽  
Functional Study ◽  
Stable Form ◽  
Functional Theory ◽  
Silane Coupling ◽  
The Stability

Using density functional theory, we predicted the solution structure of the hydrolyzed 3–aminopropyltriethoxysilane (h–APS), which is a silane coupling agent commonly used in many industrial applications. We have located five stable minima on the potential energy surface of h–APS in which four of them are "neutral", and the remaining one is zwitterionic (dipolar) in nature. Our calculations suggested that the stability of the most stable form of h–APS in water (denoted as II_N) arose from strong intramolecular OH ⋯ N hydrogen bond. The least stable form is the zwitterionic form (I_ZW), which is estimated to be over 90 kJ mol -1 less stable than II_N. The factors governing the relative stabilities of different forms are discussed.

Biomechanics of axial load transmission across the native human elbow

2020 ◽  
pp. 175857322096102
Author(s):  
Kaleb Smithson ◽  
Jacob Smith ◽  
William Hogue ◽  
Erin Mannen ◽  
Shahryar Ahmadi
Keyword(s):  
Elbow Joint ◽  
Elbow Flexion ◽  
Upper Extremities ◽  
Forearm Rotation ◽  
Contact Areas ◽  
Load Transmission ◽  
Pressure Mapping ◽  
Average Maximum ◽  
Significant Difference ◽  
Fresh Frozen

Background Elbow and forearm motion are thought to affect elbow load transmission, yet little empirical evidence exists to quantify the biomechanics. Methods Eight fresh-frozen human cadaver upper extremities were utilized. A 100 N axial force was applied across the elbow joint at elbow flexion angles of (0°, 30°, 60°, and 90°) and forearm rotation angles (0°, 45° supination, and 45° pronation). Pressure mapping sensors were placed in both the radiocapitellar and ulnotrochlear joints. Force distributions and contact areas were measured, and paired t-tests were used for comparison (p < 0.05). Results The average maximum loading percentage of the radiocapitellar and ulnotrochlear joint pressures were 57.8 ± 4.6% and 42.2 ± 4.6%, respectively. Elbow flexion angle and forearm rotation did not significantly affect the joint loading. There was no significant difference between the contact areas of each joint, although ulnotrochlear and radiocapitellar joints demonstrated an inverse relationship. Conclusion Our study is the only one to date to comprehensively evaluate loading mechanics throughout both functional elbow flexion and forearm rotation across both articulations. The load sharing ratio across the radiocapitellar and ulnotrochlear joints was 58%:42%, agreeing with previously reported ratios with limited parameters. A relationship may be present between increasing radiocapitellar and decreasing ulnotrochlear contact areas as elbow flexion increases.

Nitrogen-doped carbon supports with terminated hydrogen and their effects on active gold species: a density functional study

2014 ◽  
Vol 16 (46) ◽  
pp. 25498-25507 ◽  
Author(s):  
Junjie Gu ◽  
Qian Du ◽  
You Han ◽  
Zhenghua He ◽  
Wei Li ◽  
...  
Keyword(s):  
Valence State ◽  
Density Functional ◽  
Functional Study ◽  
Carbon Supports ◽  
Acetylene Hydrochlorination ◽  
Density Functional Study ◽  
Nitrogen Doped ◽  
Doped Graphene ◽  
The Stability ◽  
Nitrogen Doped Carbon

The stabilities of gold species on N-doped graphene increase with its valence state. Au2Cl6 interacts preferentially with HCl on N-doped supports, enhancing the stability of Au catalysts for acetylene hydrochlorination.

Applying a Hybrid Experimental-Computational Technique to Study Elbow Joint Ligamentous Stabilizers

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Danial Sharifi Kia ◽  
Ryan Willing
Keyword(s):  
Soft Tissue ◽  
Elbow Joint ◽  
Computational Technique ◽  
Joint Stability ◽  
Collateral Ligament ◽  
Principle Of Superposition ◽  
Flexion Extension ◽  
Joint Biomechanics ◽  
The Stability

Much of our understanding of the role of elbow ligaments to overall joint biomechanics has been developed through in vitro cadaver studies using joint motion simulators. The principle of superposition can be used to indirectly compute the force contributions of ligaments during prescribed motions. Previous studies have analyzed the contribution of different soft tissue structures to the stability of human elbow joints, but have limitations in evaluating the loads sustained by those tissues. This paper introduces a unique, hybrid experimental-computational technique for measuring and simulating the biomechanical contributions of ligaments to elbow joint kinematics and stability. in vitro testing of cadaveric joints is enhanced by the incorporation of fully parametric virtual ligaments, which are used in place of the native joint stabilizers to characterize the contribution of elbow ligaments during simple flexion–extension (FE) motions using the principle of superposition. Our results support previously reported findings that the anterior medial collateral ligament (AMCL) and the radial collateral ligament (RCL) are the primary soft tissue stabilizers for the elbow joint. Tuned virtual ligaments employed in this study were able to restore the kinematics and laxity of elbows to within 2 deg of native joint behavior. The hybrid framework presented in this study demonstrates promising capabilities in measuring the biomechanical contribution of ligamentous structures to joint stability.

A Density Functional Study of Structure and Stability of Ni8, Ni8 + and Ni8 − Cluster

2005 ◽  
Vol 1 (4) ◽  
pp. 172-182 ◽  
Author(s):  
Patrizia Calaminici ◽  
Marcela R. Beltrán
Keyword(s):  
Density Functional ◽  
Local Density ◽  
Structural Parameters ◽  
Binding Energies ◽  
Functional Study ◽  
Generalized Gradient ◽  
Exchange Correlation ◽  
Generalized Gradient Approximation ◽  
The Stability ◽  
Anionic Cluster

Density functional calculations of neutral, cationic and anionic nickel octamer are presented. The structure optimization and frequency analysis were performed on the local density approximation (LDA) level with the exchange correlation functional by Vosko,Wilk and Nusair (VWN). Improved calculations for the stability were based on the generalized gradient approximation (GGA) where the exchange correlation functional of Perdew and Wang (PW) was used. For neutral, cationic and anionic cluster several isomers and different spin multiplicities were investigated in order to find the lowest structures. Structural parameters, relative energies, binding energies, harmonic frequencies, adiabatic ionization potential and electron affinity will be presented. The calculated values are compared with available experimental data.

scholarly journals Kinematic instrumental analysis of the shoulder and elbow joint in normal conditions and with hypermobility of the joint in the gait cycle

2019 ◽  
Vol 7 (1) ◽  
pp. 35-42
Author(s):  
Olga I. Vorontcova ◽  
Larisa A. Udochkina ◽  
Marina S. Baranec ◽  
Marina V. Grechitaeva ◽  
Ludmila A. Goncharova
Keyword(s):  
Internal Rotation ◽  
Shoulder Joint ◽  
Elbow Joint ◽  
External Rotation ◽  
Joint Hypermobility ◽  
Instrumental Method ◽  
Joint Hypermobility Syndrome ◽  
Arm Swing ◽  
Common Sign ◽  
Analysis System

Background. There is evidence for violation or a complete change in the arm swing cycle during walking in a number of pathologic conditions. Aim. We assess the functional state of the shoulder and elbow joints in normal conditions and with joint hypermobility syndrome (JHS) using the kinematic instrumental method of analyzing gait. Material and methods. We studied 27 adolescent girls 1215 years old with JHS and healthy subjects. A Vicon motion capture analysis system (Vicon, Oxford, Great Britain) was used to record biomechanical parameters. Results. A decrease in limb movement amplitudes was noted in the shoulder joint around the frontal and sagittal axes in patients with JHS compared to the norm. During the arm swing cycle in the normal state, the shoulder is in a state of internal rotation, whereas in the girls with JHS, the shoulder is in a state of external rotation for most of the arm swing cycle. The elbow joint in the JHS subjects showed a significant increase in flexion angle of the forearm in the swing phase of 41.5 0.90 and a decrease in this angle in the stance phase. The JHS group also showed a decrease in power of the muscles acting on the shoulder joint. Conclusions. A common sign of changes in the range of motion of the links of the upper limb in the shoulder and elbow joints in subjects with JHS was decreased amplitude of their flexion and decreased power of the joints. In the adolescents with JHS in the shoulder joint, a significant decrease in the internal rotation angles and reduction of the limb was found.

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