Search Results
Results 351 - 400 of 813
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Haberl Hannes - - 2004
Experimental data suggest that lumbar torsion contributes to lumbar disc degenerative changes, such as instability, spondylolisthesis and spinal canal stenosis. However, some basic mechanical characteristics of the lumbar spine under torsional loading have not yet been reported in detail. For example, the function of the facet joints under combined mechanical ...
Parkinson Robert J - - 2004
OBJECTIVE: To quantify the time-varying stiffness and kinematic responses of the in vivo lumbar spine exposed to dynamic repetitive flexion movements. DESIGN: Changes in in vivo passive lumbar moment-angle relationships were monitored in response to dynamic repetitive flexion. BACKGROUND: While previous in vitro studies have provided conflicting evidence on the ...
Del Rossi Gianluca - - 2004
STUDY DESIGN: A repeated-measures design using a cadaveric model was used in this preliminary investigation on the effectiveness of spine-board transfer techniques. OBJECTIVES: To compare the amount of angulation (flexion-extension) motion that results at the cervical spine during the execution of the log-roll maneuver and the lift-and-slide technique; and to ...
Elliott Dawn M - - 2004
STUDY DESIGN: Measure the mechanical properties of the mouse and rat disc in compression and torsion. OBJECTIVES: Validate mouse and rat disc as a biomechanical model of the human disc by comparing the normalized properties in compression and torsion loading. SUMMARY OF BACKGROUND DATA: Rodents have been widely used as ...
Hamaoui A - - 2004
This study questioned whether postural sway increase in low back pain subjects was related to impaired spine mobility, and especially to a decrease in the range of motion, which was assumed to represent structural spine stiffness. Ten low back pain subjects and ten healthy control subjects performed spine flexion-extension and ...
Ianuzzi Allyson - - 2004
BACKGROUND CONTEXT: The lumbar facet joint capsule is innervated with nociceptors and mechanoreceptors, and is thought to play a role in low back pain as well as to function proprioceptively. PURPOSE: In order to examine the facet capsule's potential proprioceptive role, relationships between intracapsular strain and relative spine position were ...
Puttlitz Christian M - - 2004
BACKGROUND: Craniovertebral arthrodesis in the upper cervical spine is challenging because of the high degree of mobility afforded by this region. A novel method for achieving atlantoaxial fixation with use of polyaxial screws inserted bilaterally into the lateral masses of C1 and transpedicularly into C2 with longitudinal rod connection has ...
Kuroki Hiroshi - - 2004
STUDY DESIGN: An in vitro biomechanical cadaveric study. OBJECTIVES To elucidate the effect of flexion-extension cyclic loads on the motion behavior of lumbar spine after different discectomies. SUMMARY OF BACKGROUND DATA: Biomechanical cadaveric studies to evaluate the effect of discectomy have been performed and have indicated the relevance between the ...
Kulig Kornelia - - 2004
STUDY DESIGN: Descriptive study. OBJECTIVE: The purpose of this study was to describe the segmental motion of the lumbar spine during a posterior-to-anterior (PA) mobilization procedure using dynamic magnetic resonance imaging and to propose a mechanism of the lumbar spine's motion as a result of a PA force to a ...
Gardner-Morse Mack G - - 2004
The objectives of this study were to obtain linearized stiffness matrices, and assess the linearity and hysteresis of the motion segments of the human lumbar spine under physiological conditions of axial preload and fluid environment. Also, the stiffness matrices were expressed in the form of an 'equivalent' structure that would ...
Vander Kooi Douglas - - 2004
STUDY DESIGN: L3-L5 vertebral body motion was tracked fluoroscopically as individuals performed flexion-extension movements wearing different thoracolumbosacral orthoses (TLSOs). OBJECTIVE: To assess the effect of custom fitted TLSOs on lumbar vertebral body motion. SUMMARY OF BACKGROUND DATA: Several methods have been used to evaluate dynamic vertebral motion in vivo. Controversy ...
Dhanrajan Tiruchinapalli M - - 2004
Evidence for morphological substrates of long-term changes in synaptic efficacy is controversial, partly because it is difficult to employ an unambiguous control. We have used a high-frequency stimulation protocol in vivo to induce long-term potentiation (LTP) in the hippocampal dentate gyrus of aged (22-month-old) rats and have found a clear ...
Vogt Lutz - - 2003
External tracking of three-dimensional lumbar spine and pelvic oscillations is a method recently used in clinical gait analysis. This investigation validated the use of plate mounted marker configurations overlying the median sacral crest (S1) against single marker sets placed over the anterior and posterior superior iliac spine for the assessment ...
Klein P - - 2003
OBJECTIVE: Determination of the three-dimensional kinematics of the head relative to the upper trunk obtained during a manipulation applied on two different cervical levels and on both sides. DESIGN: Descriptive study performed on 14 asymptomatic volunteers. The range of motion was measured by a 3D electrogoniometer during manipulation executed by ...
Lewandowski Jacek - - 2003
The aim of the study has been to evaluate the range of motion of the cervical spine in relation to the age of the participants, and to determine the dimorphic and asymmetrical differences in the range of motion in pre-determined age categories. The study involved 300 children (150 girls and ...
Holt P J E - - 2003
Low back pain is a common problem in rowers of all levels. Few studies have looked at the relationship between rowing technique, the forces generated during the rowing stroke and the kinematics of spinal motion. Of particular concern with respect to spinal injury and damage are the effects of fatigue ...
Colloca Christopher J - - 2003
OBJECTIVE: To simultaneously quantify vertebral motions and neuromuscular and spinal nerve root responses to mechanical force, manually assisted, short-lever spinal manipulative thrusts. METHODS: Four patients underwent lumbar laminarthrectomy to decompress the central spinal canal and neuroforamina, as clinically indicated. Prior to decompression, finely threaded, 1.8-mm diameter intraosseous pins were rigidly ...
Gavin Thomas M - - 2003
The analysis of current cervical collars (Aspen and Miami J collars) and cervical thoracic orthoses (CTOs) (Aspen 2-post and Aspen 4-post CTOs) in reducing cervical intervertebral and gross range of motion in flexion and extension was performed using 20 normal volunteer subjects. The gross sagittal motion of the head was ...
Keller Tony S - - 2003
OBJECTIVE: To quantify in vivo spinal motions and coupling patterns occurring in human subjects in response to mechanical force, manually assisted, short-lever spinal manipulative thrusts (SMTs) applied to varying vertebral contact points and utilizing various excursion (force) settings. METHODS: Triaxial accelerometers were attached to intraosseous pins rigidly fixed to the ...
Cunningham Bryan W - - 2003
STUDY DESIGN: This in vitro biomechanical study was undertaken to quantify the multidirectional intervertebral kinematics following total disc replacement arthroplasty compared to conventional stabilization techniques. OBJECTIVE: Using an in vitro human cadaveric model, the primary objective was to compare the multidirectional flexibility properties and map the center of intervertebral rotation ...
Miyamoto Hiroshi - - 2003
STUDY DESIGN: Biomechanical analysis of the movement of the lumbar spinal nerve roots (NRs). OBJECTIVES: The characteristics of the movement of lumbar spinal NRs corresponding to the change of posture were three-dimensionally analyzed in nonsimulated and simulated adhesion conditions using a porcine model. SUMMARY OF BACKGROUND DATA: There is a ...
Cholewicki Jacek - - 2003
The amounts of thoracic and lumbar spine motion restriction and passive trunk stiffness provided by three thoracolumbosacral orthoses (TLSOs) (Aspen TLSO, Boston Body Jacket, and CAMP TLSO) were compared. Ten subjects executed maximum trunk flexion, extension, and lateral bending motions. The spine motion was measured noninvasively with a thin strain ...
Wigfield Crispin C - - 2003
There is concern that cervical interbody fusion can result in accelerated degenerative changes occurring at adjacent spinal levels. The cervical spine clearly evolved to be mobile. It would seem to be desirable for spinal surgeons to have an alternative to fusion, and spinal arthroplasty is an appealing concept. The Bristol ...
JASON S. ANDERSON
The cranial anatomy of Coloraderpeton brilli Vaughn and postcranial anatomy of Oestocephalus amphiuminus Cope are reconsidered in light of new ophiderpetontid material from Nýřany, Czech Republic. Coloraderpeton is distinct from Oestocephalus amphiuminus in having a quadrate region extended farther posterior of the occiput and a tabular restricted from the lateral ...
Detwiler Paul W - - 2003
OBJECT: The authors compared differences in biomechanical stability between two decompressive laminectomy techniques for treating lumbar stenosis. A Christmas tree laminectomy (CTL), in which bilateral facetectomies and foraminotomies are performed, was compared with facet-sparing laminectomy (FSL), in which the facets are undercut but not resected. Spinal instability was assessed immediately ...
Egloff Boris - - 2003
This article proposes the differentiation of Joy, Interest, and Activation in the Positive Affect (PA) scale of the Positive and Negative Affect Schedule (PANAS; D. Watson, L. A. Clark, & A. Tellegen, 1988). Study 1 analyzed the dynamic course of PA before, during, and after an exam and established the ...
Gorden Jeffery A. - - 2003
OBJECTIVES: To evaluate the effectiveness of 3 football collars in reducing cervical range of motion. DESIGN AND SETTING: A repeated-measures design in a controlled laboratory setting. SUBJECTS: Fifteen male National Collegiate Athletic Association Division I varsity football athletes. MEASUREMENTS: Cervical hyperextension and lateral flexion were measured with video analysis. Subjects ...
Amodei Dario - - 2003
The point-spread function and emissivity are calculated for a mirror made from regular hexagonal segments of just a few different sizes. A mirror of this type has many similar segments, which is an advantage for manufacturing, and for an approximately f/1 mirror with > or = 1000 segments and > ...
Nihei Aki - - 2003
The structure of the ligamentum flavum has yet to be fully elucidated and no studies have investigated fine structural differences at different spinal levels in any animals. The aim of the present study was to clarify structural differences in the ligamentum flavum at different spinal levels (cervical: C3/4 and C5/6; ...
Patwardhan Avinash G AG Musculoskeletal Biomechanics Laboratory, Department of Veterans Affairs, Edward J. Hines Veterans Affairs Hospital, Hines, Illinois 60141, USA. - - 2003
Insertion of an anterior lumbar interbody fusion cage has been shown to reduce motion in a human spine segment in all loading directions except extension. The "stand-alone" cages depend on compressive preload produced by anular pretensioning and muscle forces for initial stabilization. However, the effect that the in vivo compressive ...
Schmoelz W - - 2003
In recent years, nonfusion stabilization of the lumbar spine has gained more and more popularity. These nonfusion systems intend to maintain or restore the intersegmental motions to magnitudes of the intact spine and have no negative effects on the segments adjacent to the stabilized one. This study investigated the DYNESYS, ...
DiAngelo Denis J - - 2003
An in vitro biomechanical study was conducted to determine the effects of fusion and nonfusion anterior cervical instrumentation on cervical spine biomechanics in a multilevel human cadaveric model. Three spine conditions were studied: harvested, single-level artificial cervical joint, and single-level graft with anterior cervical plate. A programmable testing apparatus was ...
Shimamoto Norimichi - - 2003
STUDY DESIGN: A nondestructive biomechanical investigation among five anterior spinal instrumentation systems for scoliosis. OBJECTIVES: The purpose of this study is to analyze the static and dynamic biomechanical stability of five different systems. SUMMARY OF BACKGROUND DATA: Although a variety of anterior spinal instrumentation systems for scoliosis are available, very ...
Vorro Joseph - - 2003
In part 2 of their report, the authors continue to evaluate myoelectric data obtained from spinal motion dynamics involved in clinical rotation tests. They add to the ipsilateral regional analysis of motor performance as previously presented and analyze the total bilateral myoelectric activity gathered concurrently at individual thoracic vertebral segments ...
Walsh E Geoffrey - - 2003
Subjects sat on a 'Balans' chair supported by the shaft of a large torque generator. The lower but not the upper part of the body was free to make to/fro movements maintained by feeding back a modified velocity signal to the generator. The stiffness could be increased by the use ...
Gardner-Morse Mack G - - 2003
The stiffness of motion segments, together with muscle actions, stabilizes the spinal column. The objective of this study was to compare the experimentally measured load-displacement behavior of porcine lumbar motion segments in vitro with physiological axial compressive preloads of 0, 200 and 400 N equilibrated in a physiological fluid environment, ...
Averbeck Bruno B BB Brain Sciences Center, Veterans Affairs Medical Center, Minneapolis, MN 55417, - - 2003
In drawing a copy of a geometrical shape, a sequence of movements must be produced to represent the sides of the object in the proper spatial relationship. We investigated neural mechanisms of this process by training monkeys to draw (using a joystick) copies of geometrical shapes (triangles, squares, trapezoids and ...
Parks K A - - 2003
STUDY DESIGN: A clinical convenience sample of workers with low back problems was tested once for a variety of parameters. OBJECTIVES: To quantify the links between lumbar range of motion and scores obtained from functional evaluation tests. SUMMARY OF BACKGROUND DATA: Although lumbar range of motion traditionally has been the ...
Mihara Hisanori - - 2003
STUDY DESIGN: Biomechanical analysis of the level above pars defects was performed using calf lumbar spines. OBJECTIVES: To evaluate whether complete spondylolysis contributes to the pathology of the upper adjacent motion segment to the pars defect. SUMMARY OF BACKGROUND DATA: It is well recognized that patients with spondylolysis show a ...
Przybylski Mirosław - - 2003
The pattern of microhabitat preferences of spined loach was examined in a natural, unpolluted lowland river. This fish co-occurred with 9 other species but non-random association was noted only with Ukrainian Lamprey, the most abundant species in the studied fish community. Spined loach was distributed only in areas adjacent to ...
Stemper Brian D - - 2003
A comprehensive characterization of the biomechanics of the cervical spine in rear impact will lead to an understanding of the mechanisms of whiplash injury. Cervical kinematics have been experimentally described using human volunteers, full-body cadaver specimens, and isolated and intact head-neck specimens. However, forces and moments at the cervico-thoracic junction ...
Wright Thomas C TC - - 2003
There is a resurgence of interest in the use of visual techniques to identify cervical intraepithelial neoplasia (CIN). These visual techniques can be divided into two general categories. One is the simple visual screening method, such as direct visual inspection (DVI), during which the cervix is visualized with either the ...
Seaver Elaine C - - 2003
Understanding the evolutionary origins of segmented body plans in the metazoa has been a long-standing fascination for scientists. Competing hypotheses explaining the presence of distinct segmented taxa range from the suggestion that all segmentation in the metazoa is homologous to the proposal that segmentation arose independently many times, even within ...
Causa F - - 2002
Structure-function relationship of natural tissues is crucial to design a device mimicking the structures present in human body. For this purpose, to provide guidelines to design an intervertebral disc (IVD) substitute, in this study the influence of the spatial location and structural components on the mechanical properties of porcine IVD ...
Lotz J C - - 2002
Intervertebral disc degeneration has been linked in humans to extreme spinal loading regimens. However, mechanisms by which spinal force influences disc cellularity, morphology and consequently biomechanical function are unclear. To gain insight into mechanobiological interactions within the disc, we developed an in vivo murine tail-compression model. Results from this model ...
Windsor Robert E - - 2002
STUDY DESIGN: Fluoroscopically guided, minimum threshold electrical stimulation of the right first, second, third, and fourth lumbar medial branches and the fifth lumbar dorsal ramus in each of eight healthy test subjects was performed. The stimulation thresholds and referral patterns were recorded. A composite drawing of the referral patterns was ...
DiAngelo Denis J - - 2002
An in vitro biomechanical study was conducted to determine the effects of anterior stabilization on lumbar interbody cage fusion biomechanics in a multilevel human cadaveric lumbar model. Three spine conditions were compared: harvested, bilateral multilevel cages (CAGES), and CAGES with bioabsorbable anterior plates (CBAP), tested under flexion/extension, lateral bending, and ...
Winkelstein Beth A - - 2002
The flexibility matrix currently forms the basis for multibody dynamics models of cervical spine motion. While studies have aimed to determine cervical motion segment behavior, their accuracy and utility have been limited by both experimental and analytical assumptions. Flexibility terms have been primarily represented as constants despite the spine's nonlinear ...
Keller Tony S - - 2002
BACKGROUND: Clinicians apply posteroanterior (PA) forces to the spine for both mobility assessment and certain spinal mobilization and manipulation treatments. Commonly applied forces include low-frequency sinusoidal oscillations (<2 Hz) as used in mobilization, single haversine thrusts (<0.5 seconds) as imparted in high-velocity, low-amplitude (HVLA) manipulation, or very rapid impulsive thrusts ...
Rao Raj D - - 2002
BACKGROUND CONTEXT: Bilateral laminotomy has been proposed as an alternative to laminectomy for decompression of lumbar spinal stenosis. Preservation of the posterior midline ligaments with laminotomy is presumed to maintain spinal segment stability. There have been no previous studies that directly compare the amount of destabilization and increase in disc ...
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