Three-dimensional force model of the low-back for simple computer programming

1990 ◽  
Vol 5 (3) ◽  
pp. 175-179 ◽  
Author(s):  
M.F. Tracy
Keyword(s):  
Computer Programming ◽  
Three Dimensional ◽  
Force Model ◽  
Low Back ◽  
Simple Computer

Optimum Design for the Frame of Open Type Abrasive Flow Polish Machine

2012 ◽  
Vol 497 ◽  
pp. 89-93
Author(s):  
Liang Liang Yuan ◽  
Ke Hua Zhang ◽  
Li Min
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Finite Element Methods ◽  
Optimization Design ◽  
Low Cost ◽  
Three Dimensional ◽  
Force Model ◽  
Optimization Analysis ◽  
Open Type ◽  
Set Up

In order to process heterotype hole of workpiece precisely, an open abrasive flow polish machine is designed, and the optimization design of machine frame is done for low cost. Firstly, basing on the parameters designed with traditional ways, three-dimensional force model is set up with the soft of SolidWorks. Secondly, the statics and modal analysis for machine body have been done in Finite element methods (FEM), and then the optimization analysis of machine frame has been done. At last, the model of rebuild machine frame has been built. Result shows that the deformation angle value of machine frame increased from 0.72′ to 1.001′, the natural frequency of the machine decreased from 75.549 Hz to 62.262 Hz, the weight of machine decreased by 74.178 Kg after optimization. It meets the strength, stiffness and angel stiffness requirement of machine, reduces the weight and cost of machine.

Three-Dimensional Torso Motion in Tethered Front Crawl Stroke and its Implications on Low Back Pain

2016 ◽  
Vol 32 (1) ◽  
pp. 50-58 ◽  
Author(s):  
Tanghuizi Du ◽  
Ikumi Narita ◽  
Toshimasa Yanai
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Range Of Motion ◽  
Twist Angle ◽  
Three Dimensional ◽  
Low Back ◽  
Front Crawl ◽  
Active Range Of Motion ◽  
High Incidence ◽  
Competitive Swimmers

Low back pain is a common problem among competitive swimmers, and repeated torso hyperextension is claimed to be an etiological factor. The purpose of this study was to describe the three-dimensional torso configurations in the front crawl stroke and to test the hypothesis that swimmers experience torso hyperextension consistently across the stroke cycles. Nineteen collegiate swimmers underwent 2 measurements: a measurement of the active range of motion in 3 dimensions and a measurement of tethered front crawl stroke at their maximal effort. Torso extension beyond the active range of torso motion was defined as torso hyperextension. The largest torso extension angle exhibited during the stroke cycles was 9 ± 11° and it was recorded at or around 0.02 ± 0.08 s, the instant at which the torso attained the largest twist angle. No participant hyperextended the torso consistently across the stroke cycles and subjects exhibited torso extension angles during tethered front crawl swimming that were much less than their active range of motion. Therefore, our hypothesis was rejected, and the data suggest that repeated torso hyperextension during front crawl strokes should not be claimed to be the major cause of the high incidence of low back pain in swimmers.

scholarly journals Semi-Automating Low Back Compression Force Estimations with an Inertial Sensor

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 37
Author(s):  
Sam Gleadhill ◽  
Daniel James ◽  
Raymond Leadbetter ◽  
Tomohito Wada ◽  
Ryu Nagahara ◽  
...  
Keyword(s):  
Motion Capture ◽  
Injury Risk ◽  
Inertial Sensors ◽  
Inertial Sensor ◽  
Three Dimensional ◽  
Compressive Force ◽  
Low Back ◽  
Compression Force ◽  
Injury Risk Factor ◽  
Capture Method

There are currently no evidence-based practical automated injury risk factor estimation tools to monitor low back compressive force in ambulatory or sporting environments. For this purpose, inertial sensors may potentially replace laboratory-based systems with comparable results. The objective was to investigate inertial sensor validity to monitor low back compression force. Thirty participants completed a series of lifting tasks from the floor. Back compression force was estimated using a hand calculated method, an inertial sensor method and a three-dimensional motion capture method. Results demonstrated that semi-automation with a sensor had a higher agreement with motion capture compared to the hand calculated method, with angle errors of less than six degrees and back compression force errors of less than 200 Newtons. It was concluded that inertial sensors are valid to implement for static low back compression force estimations.

Hybrid imaging (SPECT/computed tomography) with three-dimensional reconstruction: a new diagnostic tool for the study of low back pain after spinal fusion surgery

2015 ◽  
Vol 15 (2) ◽  
pp. 377-378 ◽  
Author(s):  
Estefania López Rodriguez ◽  
Rosario Garcia Jimenez ◽  
Marta Sanchez Aguilar ◽  
Julio Valencia Anguita ◽  
Javier Luis Simon
Keyword(s):  
Computed Tomography ◽  
Low Back Pain ◽  
Back Pain ◽  
Diagnostic Tool ◽  
Hybrid Imaging ◽  
Three Dimensional ◽  
Low Back ◽  
Fusion Surgery ◽  
Spinal Fusion Surgery ◽  
Dimensional Reconstruction

Numerical Simulation of Touchdown/Takeoff Hysterisis of Spherical Pad Slider by Considering the Liquid Bridge Between the Slider and Lubricant-Disk

2008 ◽  
Author(s):  
Hui Li ◽  
Jianhua Li ◽  
Junguo Xu ◽  
Yuki Shimizu ◽  
Kyosuke Ono ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Liquid Bridge ◽  
3D Model ◽  
Three Dimensional ◽  
Disk Surface ◽  
Force Model ◽  
Disk Interface ◽  
Meniscus Force ◽  
Geometry Model ◽  
Balance State

This work carries on a numerical simulation of the touchdown/takeoff (TD/TO) hysterisis of the spherical pad slider. It numerically studies the meniscus bridge’s formation and meniscus force interaction between the spherical pad and lubricant over the disk surface. It proposes a geometry model for the lubricant bridge, and correspondingly, a force model for the meniscus force acting on the spherical pad slider due to the lubricant bridge. By solving the liquid balance state at the meniscus boundary, it obtains the geometry of the liquid bridge. A parametric study is done to study the effects of the geometry of spherical pad, Hamaker constant of lubricant-disk, and surface energy of lubricant on the formation of the liquid bridge. The overflow phenomenon is analyzed to find out the acceptable dimension of the spherical pad design. Moreover, a three-dimensional (3D) model of spherical pad slider/disk interface is built to study the steady-state flying of the spherical pad slider. The different parameters are analyzed to study their effects on the TD/TO hysteresis.

Intervertebral Disc Shape Variation and its Relationship to Degeneration Using Principal Components Analysis of a Population of MR Images

2012 ◽  
Author(s):  
John M. Peloquin ◽  
Jonathon H. Yoder ◽  
Nathan T. Jacobs ◽  
Sung M. Moon ◽  
Alexander C. Wright ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Intervertebral Disc ◽  
Material Properties ◽  
Three Dimensional ◽  
Low Back ◽  
Shape Variation ◽  
Mr Images ◽  
Physiological Basis ◽  
Prevalent Disease ◽  
Components Analysis

Degeneration of the intervertebral disc (IVD) is implicated in low back pain, which is a costly and prevalent disease. Since the IVD is a mechanically active organ, it is important to consider its mechanical behavior as one factor in the degenerate pathology. Strain can be measured directly by imaging methods, but the stress distribution within the disc must be calculated. The stress distribution for a particular strain state is dependent on the IVD’s material properties and its geometry. While the material properties of the tissues comprising IVD have been extensively studied, its three-dimensional geometry remains incompletely characterized. Prior whole-disc models have been constructed from single IVDs. While this approach ensures that the geometry has a physiological basis, it is uncertain the degree to which results from a single IVD shape can be generalized to the entire population.

In Vivo Three-Dimensional Morphometric Analysis of the Lumbar Spinal Bony Canal in Healthy and Low Back Pain Patients

2011 ◽  
Author(s):  
J. S. An ◽  
A. A. Espinoza Orías ◽  
H. S. An ◽  
G. B. J. Andersson ◽  
N. Inoue
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Imaging Technique ◽  
Three Dimensional ◽  
Low Back ◽  
Bony Canal ◽  
Three Dimensional Models ◽  
Lumbar Spinal ◽  
Pain Patients

To accurately quantify the anatomic parameters of the lumbar spinal bony canal using a novel three-dimensional imaging technique based on in vivo CT three-dimensional models.

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