«Terrible triad» of the shoulder. Biomechanicalsemi-natural modeling andjustificationto rotator cuff restoration

The aim of this study: was determine the force of tension and deformation of axillary nerve in rupture rotator cuff and paresis of deltoid muscle of the shoulder joint. Material and methods: Semi-natural modelling based on the axial scans spiral computed tomography of the intact shoulder joint was performed to determine the degree of traction load on the axillary nerve with distal displacement shoulder head and tendon rupture which paresis of the deltoid muscle. Result: The values of deformations for axillary nerve being at the limit of tissue strength at distal displacement of humeral head of the model by 50 %, progressively increased with increasing distal displacement of humeral head to 100 % of its diameter, reaching values 1.7 times higher than the strength nervous tissue. Conclusion: The progressive changes occurring in the axillary nerve under the action of traction loads, and as a consequence of its ischemia, over time can lead not only to demyelination, but also to the defeat of the axons themselves atrophy of its fibers. In turn, deltoid muscle atrophy increases the traction load on the affected axillary nerve, which forms a vicious circle. The only possible option to "break" the vicious circle is restore the stabilizing structures damaged during the injury, among which one of the most important is the tendons of the rotator cuff of the shoulder. Surgical restoration of the integrity rotator cuff of the shoulder reduces the traction load acting on the axillary nerve, which in turn significantly improves the conditions for reinnervation of the deltoid muscle.

A Novel Optimized Finite Element Model of Lenke 1 Adolescent Idiopathic Scoliosis Based on Dynamic Flexibility in Vivo

Bacground: It is of great significance to optimize the finite element model by spinal flexibility of adolescent idiopathic scoliosis (AIS) patients. The elastic modulus of the intervertebral disc is of critical importance in determining the overall flexibility of the spine. The aim of the present study was to optimize the finite element model of Lenke 1 AIS based on the dynamic flexibility in vivo by matching the optimal elastic modulus of the intervertebral disc.Methods: The Cobb angles under different longitudinal traction loads of one patient with Lenke 1 AIS were dynamically measured by using a spine morphometer with a posture sensor to plot the Cobb angle-longitudinal traction load characteristic curve. A 3D finite element model of the patient was established. The patient’s Cobb angle-longitudinal traction load characteristic curve was used as the dynamic flexibility in vivo to determine the optimal intervertebral disc elastic modulus of the model. Results: The dynamic flexibility curve in vivo of one Lenke 1 AIS patient was successfully obtained, and the patient’s optimal elastic modulus of the intervertebral disc for the finite element model was 5 MPa according to the dynamic flexibility curve in vivo.Conclusions: The use of dynamic flexibility in vivo to optimize the finite element model can provide a new perspective and approach for model optimization, which can reproduce the biomechanical characteristics in vivo of AIS patients.

Performance of agricultural tractor with and without automatic transmission and engine rotation management

HIGHLIGHTS Electronic gear selection and autonomous engine rotation management bring benefits to tractor driving. The electronic management responded positively to the increase in the traction load. The use of electronic management software should be more widespread among farmers and researchers.

APPLICATION OF ACTIVE-ADAPTIVE NETWORK TECHNOLOGIES FOR POWER QUALITY MANAGEMENT IN ELECTRIC NETWORKS WITH TRACTION LOAD

On the basis of the system approach, the analysis of the basic technologies of the intelligent electric power system that provide adaptive management of the electric network is carried out. The expediency of their application for adaptive power quality management in electric networks with traction load by expanding the functions is shown. The variants of their configuration are proposed to improve the quality of electricity and ensure optimal parameters of electricity quality indicators.