Kinematics of the Human Pelvis Following Open Book Injury

2002 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Mohamed Samir Hefzy ◽  
Nabil Ebraheim ◽  
Anis Mekhail ◽  
Richard Yeasting
Keyword(s):  
Motion Tracking ◽  
Articular Surface ◽  
Tracking System ◽  
Three Dimensional ◽  
Vertical Displacement ◽  
X Rays ◽  
Open Book ◽  
Sacroiliac Joints ◽  
Pure Rotation ◽  
Planar Surfaces

The objective of this study is to determine the three dimensional kinematics of the human pelvis including both sacroiliac joints following a simulated open book fracture induced on cadavers by applying anterior-posterior compressive loads to the pelvis. An electromagnetic digitizing and motion tracking system was utilized to measure the morphology of the pelvis and the relative movements of its bones during this simulated open book fracture. The screw displacement axis method was used to describe the relative motions between the sacrum and each hip bone. Morphologically, it was found that the articular surfaces forming the sacroiliac joints can be approximated with planar surfaces directed from proximal and lateral to distal and medial and from posteromedial to anterolateral. The kinematic data indicate that the motion of the hip bone with respect to the sacrum on the side of the sacroiliac joint (SIJ) opening is almost a pure rotation which translates clinically on the A-P x-rays as pure opening of the SIJ without vertical displacement. The average axis of rotation was found to be almost parallel to the SIJ planar articular surface.

scholarly journals Multi-sensor three-dimensional Monte Carlo localization for long-term aerial robot navigation

2017 ◽  
Vol 14 (5) ◽  
pp. 172988141773275 ◽  
Author(s):  
Francisco J Perez-Grau ◽  
Fernando Caballero ◽  
Antidio Viguria ◽  
Anibal Ollero
Keyword(s):  
Monte Carlo ◽  
Motion Tracking ◽  
Robot Navigation ◽  
Tracking System ◽  
Three Dimensional ◽  
Measurement Unit ◽  
Indoor Environments ◽  
Localization Algorithm ◽  
Monte Carlo Localization ◽  
Motion Tracking System

This article presents an enhanced version of the Monte Carlo localization algorithm, commonly used for robot navigation in indoor environments, which is suitable for aerial robots moving in a three-dimentional environment and makes use of a combination of measurements from an Red,Green,Blue-Depth (RGB-D) sensor, distances to several radio-tags placed in the environment, and an inertial measurement unit. The approach is demonstrated with an unmanned aerial vehicle flying for 10 min indoors and validated with a very precise motion tracking system. The approach has been implemented using the robot operating system framework and works smoothly on a regular i7 computer, leaving plenty of computational capacity for other navigation tasks such as motion planning or control.

scholarly journals Validation of a single camera three-dimensional motion tracking system

2010 ◽  
Vol 43 (7) ◽  
pp. 1437-1440 ◽  
Author(s):  
Joshua T. Weinhandl ◽  
Brian S.R. Armstrong ◽  
Todd P. Kusik ◽  
Robb T. Barrows ◽  
Kristian M. O’Connor
Keyword(s):  
Motion Tracking ◽  
Tracking System ◽  
Three Dimensional ◽  
Single Camera ◽  
Motion Tracking System

Kinematic Differences Between Those With and Without Medial Knee Displacement During a Single-leg Squat

2014 ◽  
Vol 30 (6) ◽  
pp. 707-712 ◽  
Author(s):  
Timothy C. Mauntel ◽  
Barnett S. Frank ◽  
Rebecca L. Begalle ◽  
J. Troy Blackburn ◽  
Darin A. Padua
Keyword(s):  
Motion Tracking ◽  
Tracking System ◽  
Three Dimensional ◽  
Control Group ◽  
Knee Valgus ◽  
Medial Knee ◽  
Lower Extremity Injuries ◽  
Valgus Angle ◽  
Peak Knee ◽  
Single Leg Squat

A greater knee valgus angle is a risk factor for lower extremity injuries. Visually observed medial knee displacement is used as a proxy for knee valgus motion during movement assessments in an attempt to identify individuals at heightened risk for injury. The validity of medial knee displacement as an indicator of valgus motion has yet to be determined during a single-leg squat. This study compared three-dimensional knee and hip angles between participants who displayed medial knee displacement (MKD group) during a single-leg squat and those who did not (control group). Participants completed five single-leg squats. An electromagnetic motion tracking system was used to quantify peak knee and hip joint angles during the descent phase of each squat. MANOVA identified a difference between the MKD and control group kinematics. ANOVA post hoc testing revealed greater knee valgus angle in the MKD (12.86 ± 5.76) compared with the control (6.08 ± 5.23) group. There were no other differences between groups. Medial knee displacement is indicative of knee valgus motion; however, it is not indicative of greater knee or hip rotation, or hip adduction. These data indicate that clinicians can accurately identify individuals with greater knee valgus angle through visually observed medial knee displacement.

Factors Influencing Accuracy of Screw Displacement Axis Detection With a D.C.-Based Electromagnetic Tracking System

1998 ◽  
Vol 120 (3) ◽  
pp. 431-435 ◽  
Author(s):  
M. Bottlang ◽  
J. L. Marsh ◽  
T. D. Brown
Keyword(s):  
Motion Tracking ◽  
Tracking System ◽  
Three Dimensional ◽  
Joint Motion ◽  
Electromagnetic Tracking ◽  
Source Data ◽  
Surgical Setting ◽  
Smoothing Procedure ◽  
Electromagnetic Tracking System ◽  
Single Receiver

Recent technical improvements and cost reductions in electromagnetic motion tracking systems invite their application to motion axis determination in the surgical setting. After evaluation of the accuracy of a state-of-the-art D. C. electromagnetic tracking system, which generates complete three-dimensional kinematic outputs from just a single receiver, we calculated screw displacement axes (SDA’s) from its source data. The accuracy of SDA determination from such source data was evaluated for various rotational increment sizes around a revolute joint. A novel smoothing procedure, customized for this type of source data, was developed, enabling SDA detection from incremental rotations of less than 1 deg, at an accuracy appropriate for intra-operative measurement of human joint motion. Examples of SDA determination are given for motion tracking of a ball joint and of the elbow articulation.

scholarly journals Optimization and Simulation of Virtual Experiment System of Human Sports Science Based on VR

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Gaixin Li
Keyword(s):  
Virtual Reality ◽  
Motion Tracking ◽  
Tracking System ◽  
Three Dimensional ◽  
Human Motion ◽  
Flow Diagram ◽  
Virtual Experiment ◽  
Experiment System ◽  
Sports Science ◽  
Motion Tracking System

Virtual reality technology is an emerging technology developed on the basis of information technology. It is widely used in military, medical, mining, entertainment, and other fields. Therefore, many countries have been vigorously conducting research in recent years. As one of the important components of the virtual reality system, the three-dimensional human motion tracking system is of great significance to the research of practical virtual reality systems. It introduces the measurement principle of the spatial three-dimensional coordinate dynamic measurement device and discusses in detail the ultrasonic transmission, reception, amplification, filtering, comparison, shaping circuit, and single-chip interface circuit. This paper introduces the working principle and characteristics of the virtual experiment system and gives the structure diagram, hardware schematic diagram, and software flow diagram of the system. We mainly study the method of tracking human motion by measuring the three-dimensional coordinates of the space point, which lays a good foundation for the research of the actual three-dimensional motion tracking system. At the same time, the three-dimensional human body modeling is discussed, and the interactive movement policy of the human arm is briefly introduced. It has a certain effect on the actual virtual reality human-computer interaction system.

Use of a real-time three-dimensional motion tracking system for measurement of intrafractional motion of the thoracic wall in dogs

2013 ◽  
Vol 74 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Monique N. Mayer ◽  
Joel L. Lanovaz ◽  
Michael J. Smith ◽  
Narinder Sidhu ◽  
Cheryl L. Waldner
Keyword(s):  
Real Time ◽  
Motion Tracking ◽  
Tracking System ◽  
Three Dimensional ◽  
Thoracic Wall ◽  
Intrafractional Motion ◽  
Motion Tracking System

Estimation of Muscle Response Using Three-Dimensional Musculoskeletal Models Before Impact Situation: A Simulation Study

2010 ◽  
Vol 132 (12) ◽  
Author(s):  
Tae Soo Bae ◽  
Peter Loan ◽  
Kuiwon Choi ◽  
Daehie Hong ◽  
Mu Seong Mun
Keyword(s):  
Degrees Of Freedom ◽  
Motion Tracking ◽  
Tracking System ◽  
Three Dimensional ◽  
Dynamic Simulations ◽  
Inverse Dynamic ◽  
Low Speed ◽  
Car Crash ◽  
Musculoskeletal Models ◽  
Ankle Joints

When car crash experiments are performed using cadavers or dummies, the active muscles’ reaction on crash situations cannot be observed. The aim of this study is to estimate muscles’ response of the major muscle groups using three-dimensional musculoskeletal model by dynamic simulations of low-speed sled-impact. The three-dimensional musculoskeletal models of eight subjects were developed, including 241 degrees of freedom and 86 muscles. The muscle parameters considering limb lengths and the force-generating properties of the muscles were redefined by optimization to fit for each subject. Kinematic data and external forces measured by motion tracking system and dynamometer were then input as boundary conditions. Through a least-squares optimization algorithm, active muscles’ responses were calculated during inverse dynamic analysis tracking the motion of each subject. Electromyography for major muscles at elbow, knee, and ankle joints was measured to validate each model. For low-speed sled-impact crash, experiment and simulation with optimized and unoptimized muscle parameters were performed at 9.4 m/h and 10 m/h and muscle activities were compared among them. The muscle activities with optimized parameters were closer to experimental measurements than the results without optimization. In addition, the extensor muscle activities at knee, ankle, and elbow joint were found considerably at impact time, unlike previous studies using cadaver or dummies. This study demonstrated the need to optimize the muscle parameters to predict impact situation correctly in computational studies using musculoskeletal models. And to improve accuracy of analysis for car crash injury using humanlike dummies, muscle reflex function, major extensor muscles’ response at elbow, knee, and ankle joints, should be considered.

UNSUPERVISED MARKERLESS 3-DOF MOTION TRACKING IN REAL TIME USING A SINGLE LOW-BUDGET CAMERA

2012 ◽  
Vol 22 (05) ◽  
pp. 1250019 ◽  
Author(s):  
LUIS QUESADA ◽  
ALEJANDRO J. LEÓN
Keyword(s):  
Real Time ◽  
Degrees Of Freedom ◽  
Motion Tracking ◽  
Tracking System ◽  
Three Dimensional ◽  
Target Object ◽  
Commercial Applications ◽  
Amount Of Knowledge ◽  
Partially Occluded ◽  
Motion Tracking System

Motion tracking is a critical task in many computer vision applications. Existing motion tracking techniques require either a great amount of knowledge on the target object or specific hardware. These requirements discourage the wide spread of commercial applications based on motion tracking. In this paper, we present a novel three degrees of freedom motion tracking system that needs no knowledge on the target object and that only requires a single low-budget camera that can be found installed in most computers and smartphones. Our system estimates, in real time, the three-dimensional position of a nonmodeled unmarked object that may be nonrigid, nonconvex, partially occluded, self-occluded, or motion blurred, given that it is opaque, evenly colored, enough contrasting with the background in each frame, and that it does not rotate. Our system is also able to determine the most relevant object to track in the screen. Our proposal does not impose additional constraints, therefore it allows a market-wide implementation of applications that require the estimation of the three position degrees of freedom of an object.

Proximal Overresection During Femoral Osteochondroplasty Negatively Affects the Distractive Stability of the Hip Joint: A Cadaver Study

2021 ◽  
pp. 036354652110289
Author(s):  
Lionel E. Lazaro ◽  
Daniel P. Lim ◽  
Trevor J. Nelson ◽  
Sam A. Eberlein ◽  
Michael B. Banffy ◽  
...  
Keyword(s):  
Femoral Head ◽  
Hip Joint ◽  
Motion Tracking ◽  
External Rotation ◽  
Articular Surface ◽  
Tracking System ◽  
Metal Plate ◽  
Rotational Stability ◽  
Rotational Instability ◽  
Proximal Extension

Background: Contact between the acetabular labrum and articular cartilage of the femoral head creates a suction seal that helps maintain stability of the femoral head in the acetabulum. A femoral osteochodroplasty may occasionally extend proximally into the femoral head, diminishing the articular surface area available for sealing contact. Purpose: To determine whether proximal overresection decreases the rotational and distractive stability of the hip joint. Study Design: Controlled laboratory study. Methods: Six hemipelvises in the following conditions were tested: intact, T-capsulotomy, osteochondroplasty to the physeal scar, and 5- and 10-mm proximal extension. The pelvis was secured to a metal plate, and the femur was potted and attached to a multiaxial hip jig. Specimens were axially distracted using a load from 0 to 150 N. For rotational stability testing, 5 N·m of internal and external torque was applied. Both tests were performed at different angles of flexion (0°, 15°, 30°, 60°, 90°). Displacement and rotation were recorded using a 3-dimensional motion tracking system. Results: The T-capsulotomy decreased the distractive stability of the hip joint. A femoral osteochondroplasty up to the physeal scar did not seem to affect the distractive stability. However, a proximal extension of the resection by 5 and 10 mm increased axial instability at every angle of flexion tested, with the greatest increase observed at larger angles of flexion ( P < .01). External rotation increased significantly after T-capsulotomy in smaller angles of flexion (0°, P = .01; 15°, P = .01; 30°, P = .03). Femoral osteochondroplasty did not create further external rotational instability, except when the resection was extended 10 mm proximally and the hip was in 90° of flexion ( P = .04). Conclusion: This cadaveric study demonstrated that proximal extension of osteochondroplasty into the femoral head compromises the distractive stability of the hip joint but does not affect hip rotational stability. Clinical Relevance: Clinically, this study highlights the importance of accuracy when performing femoral osteochondroplasty to minimize proximal extension that may increase iatrogenic instability of the hip joint.

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