41 results match your criteria anteriorly flexibility

Bendy to the bone: Links between vertebral morphology and waterfall climbing in amphidromous gobioid fishes.

J Anat 2021 Apr 29. Epub 2021 Apr 29.

Department of Biological Sciences, Clemson University, Clemson, SC, USA.

Locomotor force production imposes strong demands on organismal form. Thus, the evolution of novel locomotor modes is often associated with morphological adaptations that help to meet those demands. In the goby lineage of fishes, most species are marine and use their fused pelvic fins to facilitate station holding in wave-swept environments. Read More

View Article and Full-Text PDF

Biomechanics of Circumferential Cervical Fixation Using Posterior Facet Cages: A Cadaveric Study.

Neurospine 2021 Mar 31;18(1):188-196. Epub 2021 Mar 31.

Spinal Biomechanics Laboratory, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA.

Objective: Anterior cervical discectomy and fusion (ACDF) is a common procedure for the treatment of cervical disease. Circumferential procedures are options for multilevel pathology. Potential complications of multilevel anterior procedures are dysphagia and pseudarthrosis, whereas potential complications of posterior surgery include development of cervical kyphosis and postoperative chronic neck pain. Read More

View Article and Full-Text PDF

Diverse Routes toward Early Somites in the Mouse Embryo.

Dev Cell 2021 01 11;56(1):141-153.e6. Epub 2020 Dec 11.

Cancer Research UK Cambridge Institute, University of Cambridge, CB2 0RE Cambridge, UK; Wellcome Sanger Institute, Wellcome Genome Campus, CB10 1SA Cambridge, UK; European Molecular Biology Laboratory, European Bioinformatics Institute, European Molecular Biology Laboratory, EBI), Wellcome Genome Campus, CB10 1SD Cambridge, UK. Electronic address:

Somite formation is foundational to creating the vertebrate segmental body plan. Here, we describe three transcriptional trajectories toward somite formation in the early mouse embryo. Precursors of the anterior-most somites ingress through the primitive streak before E7 and migrate anteriorly by E7. Read More

View Article and Full-Text PDF
January 2021

Performance variables associated with bicycle configuration and flexibility.

J Sci Med Sport 2021 Mar 25;24(3):312-317. Epub 2020 Sep 25.

Division of Exercise Science and Sports Medicine, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, South Africa.

Objectives: Cycling races are often won by the smallest of margins. Research has focused on optimal saddle height for performance, however the relationship between freely chosen bicycle configuration and individual factors such as anthropometrics and flexibility have not yet been investigated adequately. The aim of this study was to determine if an association between power production, bicycle configuration and flexibility exists. Read More

View Article and Full-Text PDF

Is the Risk of Aorta Injury or Impingement Higher During Correction Surgery in Patients with Severe and Rigid Scoliosis?

World Neurosurg 2020 07 24;139:e626-e634. Epub 2020 Apr 24.

Department of Orthopedic Surgery, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China.

Objective: To evaluate the position of the aorta relative to the spine and the risk of aortic injury during correction surgery in patients with idiopathic severe and rigid scoliosis (main curve Cobb angle >90° and flexibility <30%).

Methods: Twenty-seven patients with severe right thoracic/thoracolumbar scoliosis were recruited. The entry point-aorta distance (EAD), the left pedicle-aorta angle (α), the left aorta angle (β), and the vertebral rotation angle (γ) were measured from 4 vertebrae above (A4) to 4 below (B4) the apical vertebra (Apex) to quantify the spatial relationship between aorta and spine. Read More

View Article and Full-Text PDF

Utilizing the Flexibility of Directional Deep Brain Stimulation Intraoperatively (if Needed) to Minimize Microelectrode Lead Repositioning.

Cureus 2019 Jul 30;11(7):e5276. Epub 2019 Jul 30.

Neurosurgery, Inova Health System, Falls Church, USA.

This index case report describes the intraoperative use of an eight-contact directional deep brain stimulation (DBS) lead to avoid adjustment and repeat microelectrode passes after the initial pass elicited side-effects that suggested a slightly anteriorly placed lead. While targeting the subthalamic nucleus (STN), intraoperative microelectrode recording (MER) confirmed that lead positioning and macrostimulation resulted in response at 1 mA but sustained dysarthria at 2 mA. This suggested a slightly anteriorly located electrode. Read More

View Article and Full-Text PDF

Persistence in postural dynamics is dependent on constraints of vision, postural orientation, and the temporal structure of support surface translations.

Exp Brain Res 2019 Mar 1;237(3):601-610. Epub 2018 Dec 1.

Department of Biomechanics, University of Nebraska at Omaha, BRB#210, Biomechanics Research Building, 6160 University Drive, Omaha, NE, 68182-0860, USA.

Activities of daily living require maintaining upright posture within a variety of environmental constraints. A healthy postural control system can adapt to different environmental constraints. Afferent sensory information is used to determine where the body is in relation to the gravitational vertical and efferent motor commands make corrections with the goal of keeping the center of mass within the base of support. Read More

View Article and Full-Text PDF

Non-structural misalignments of body posture in the sagittal plane.

Scoliosis Spinal Disord 2018 5;13. Epub 2018 Mar 5.

4Spine Disorders and Pediatric Orthopedics Department, University of Medical Sciences, 28 Czerwca 1956 135/147 Street, 61-545 Poznań, Poland.

Background: The physiological sagittal spinal curvature represents a typical feature of good body posture in the sagittal plane. The cervical and the lumbar spine are curved anteriorly (lordosis), while the thoracic segment is curved posteriorly (kyphosis). The pelvis is inclined anteriorly, and the lower limbs' joints remain in a neutral position. Read More

View Article and Full-Text PDF

Evaluation of the relationship between the static measurement of transverse arch flexibility of the forefoot and gait parameters in healthy subjects.

J Phys Ther Sci 2017 Mar 22;29(3):413-418. Epub 2017 Mar 22.

Sports Management Center, Graduate School, Bunkyo Gakuin University, Japan.

[Purpose] To investigate the relationship between the static measurement of the transverse arch of the forefoot, using a 3-dimensional (3D) foot scanner, and kinetics and kinematics of gait parameters in the sagittal plane. [Subjects and Methods] Twenty healthy subjects participated in this study. The transverse arch of the forefoot was measured under three conditions as follows: condition 1, sitting; condition 2, standing; and condition 3, foot forward and lower leg tilting anteriorly to the maximum position with heel contact. Read More

View Article and Full-Text PDF

Percutaneous access to the vertebral bodies: a video and fluoroscopic overview of access techniques for trans-, extra-, and infrapedicular approaches.

World Neurosurg 2013 Sep-Oct;80(3-4):428-35. Epub 2012 Sep 23.

Department of Neurosurgery, University of Cincinnati (UC) College of Medicine, Cincinnati, Ohio, USA; UC Neuroscience Institute, Cincinnati, Ohio, USA; Mayfield Clinic, Cincinnati, Ohio, USA. Electronic address:

Objective: With increasing popularity of percutaneous spinal access for minimally invasive spinal neurosurgery, the treatment paradigm has shifted from open approaches to vertebroplasty or kyphoplasty for degenerative spinal disease and vertebral compression fractures. Addressing the challenges of this shift, we integrate the fluoroscopic studies of these percutaneous approaches with the three-dimensional surgical anatomy. Step-by-step techniques are illustrated in video demonstrations that highlight the nuances of effective percutaneous access during spinal surgeries for vertebral compression fractures and pedicle screw fixation. Read More

View Article and Full-Text PDF
December 2013

Treatment of postburn anteriorly located neck contractures with local flaps.

J Craniofac Surg 2012 Sep;23(5):e387-90

Department of Oral and Maxillofacial Surgery, School of Stomatology, China Medical University, Shenyang, China.

Objective: The objective of this study was to summarize our experience of using local flaps for the reconstruction of neck defects after cervical contractures release, particularly of using the extended deltopectoral flaps whose distal margin was beyond the anterior axillary line even reaching dorsalis for reconstruction of anterior neck scar contractures in a single-stage procedure.

Methods: From 1987 to 2008, neck scar contractures were reconstructed using various local flaps in 68 patients with postburn anteriorly located neck contractures. The local flaps used consisted of 36 deltopectoral flaps, 6 extended deltopectoral flaps, 4 free scapular flaps, 8 neck-shoulder flaps, and 14 Z-plasties. Read More

View Article and Full-Text PDF
September 2012

The locomotory system of pearlfish Carapus acus: what morphological features are characteristic for highly flexible fishes?

J Morphol 2012 May 22;273(5):519-29. Epub 2011 Dec 22.

Steinmann-Institut für Geologie, Mineralogie und Paläontologie, Bereich Paläontologie, University of Bonn, Germany.

The body curvature displayed by fishes differs remarkably between species. Some nonmuscular features (e.g. Read More

View Article and Full-Text PDF

Occipitocervicothoracic stabilization in pediatric patients.

J Neurosurg Pediatr 2011 Jul;8(1):57-62

Department of Neurosurgery, University of Florida College of Medicine, Gainesville, Florida 32610, USA.

Object: Although rarely encountered, pediatric patients with severe cervical spine deformities and instability may occasionally require occipitocervicothoracic instrumentation and fusion. This case series reports the experience of 4 pediatric centers in managing this condition. Occipitocervical fixation is the treatment of choice for craniocervical instability that is symptomatic or threatens neurological function. Read More

View Article and Full-Text PDF

Jumping kinematics in the wandering spider Cupiennius salei.

J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2010 Jun 20;196(6):421-38. Epub 2010 Apr 20.

Friedrich-Schiller University, Institute of Sports Science, Science of Motion, Seidelstr. 20, 07749 Jena, Germany.

Spiders use hemolymph pressure to extend their legs. This mechanism should be challenged when required to rapidly generate forces during jumping, particularly in large spiders. However, effective use of leg muscles could facilitate rapid jumping. Read More

View Article and Full-Text PDF

Use of anterior tibial translation in the management of patellofemoral pain syndrome in older patients: a case series.

J Man Manip Ther 2007 ;15(4):216-24

The currently most plausible pathophysiologic theory for the etiology of pain in patients with patellofemoral pain syndrome involves abnormal mechanical stress to the patellofemoral joint. At this time, there is no consensus nor is there a sufficient body of research evidence to guide management of patients with patellofemoral pain syndrome. This means that clinicians have to rely to some extent on a mechanism-based approach. Read More

View Article and Full-Text PDF

Managing the maxillary partially edentulous patient with extensive anterior tooth loss and advanced periodontal disease using a removable partial denture: a clinical report.

J Prosthet Dent 2008 Oct;100(4):259-63

Department of Restorative Dentistry, Division of Prosthodontics, University of Washington, Seattle, WA 98195-7452, USA.

The treatment modality, a continuous occlusal rest removable partial denture, not only restored missing teeth but also stabilized the remaining dentition in a patient with advanced periodontal attachment loss. By engaging the guiding planes at the mesial surfaces of the abutments anteriorly and also the distal surfaces of the abutments posteriorly, the remaining teeth, with varying amounts of mobility, were splinted together by the framework. This conservative treatment option allows flexibility for easy repair during the life span of the prosthesis. Read More

View Article and Full-Text PDF
October 2008

Optimizing the design of preactivated titanium T-loop springs with Loop software.

Am J Orthod Dentofacial Orthop 2008 Jul;134(1):161-6

FAEPO/UNESP and FAMOSP/GESTOS, Araraquara, São Paulo, Brazil.

A TMA (Ormco Corp, Glendora, Calif) T-loop spring (TTLS), preactivated with a gable bend distal to the loop, holds promise for producing controlled tipping of the canines and translation of the posterior segment. However, there is currently no consensus as to where the preactivated gable bend or the loop should be placed, what the height of the loop should be, or how the interbracket distance changes the moments produced. Using the Loop software program (dHal, Athens, Greece), we systematically modified a . Read More

View Article and Full-Text PDF

Spinal growth modulation with an anterolateral flexible tether in an immature bovine model: disc health and motion preservation.

Spine (Phila Pa 1976) 2008 Apr;33(7):724-33

Rady Children's Hospital, San Diego, Children's Way, San Diego, California 92123, USA.

Study Design: An immature bovine model was used to evaluate multilevel anterolateral flexible tethering in a growing spine.

Objective: To evaluate radiographic, biochemical, histologic, and biomechanical results of tethered spinal growth.

Summary Of Background Data: An anterolateral flexible tether has been shown to create a kyphotic and scoliotic spinal deformity in calves. Read More

View Article and Full-Text PDF

Biodynamics. Influence of gender, power, and hand position on pelvic motion during seated cycling.

Med Sci Sports Exerc 2007 Dec;39(12):2204-11

Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.

Introduction/purpose: An understanding of normal pelvic motion during seated cycling is relevant to saddle design and bicycle fitting. In this study, we investigated the effects of gender, power, and hand position on pelvic motion throughout a pedal stroke. We also investigated whether anthropometric factors could explain any interindividual differences observed. Read More

View Article and Full-Text PDF
December 2007

Biomechanical comparison of instrumented and uninstrumented multilevel cervical discectomy versus corpectomy.

Spine (Phila Pa 1976) 2007 May;32(11):1220-6

Spinal Biomechanics, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013, USA.

Study Design: In vitro flexibility test comparing biomechanics of cervical corpectomy versus discectomy with and without instrumentation.

Objectives: To evaluate whether the additional effort required to perform multilevel discectomies instead of corpectomies is worthwhile biomechanically.

Summary Of Background Data: Both cervical corpectomy and discectomy have been shown to be effective clinically. Read More

View Article and Full-Text PDF

[Usefullness of intrasacral fixation in an extremely unstable lumbosacral spine].

No Shinkei Geka 2007 Apr;35(4):377-84

Department of Neurosurgery, National Hospital Organization Iwakuni Clinical Center, Yamaguchi 740-8510, Japan.

Intrasacral fixation technique devised by Jackson is said to provide rigid lumbosacral fixation. We treated 3 cases of lumbosacral lesions using this technique in which lumbosacral segment had become extremely unstable during surgical intervention adding to the effect of original lesions. In all cases, surgeries were performed in 2 stages, intrasacral fixation and anterior stabilization. Read More

View Article and Full-Text PDF

Biomechanical evaluation of the Total Facet Arthroplasty System: 3-dimensional kinematics.

Spine (Phila Pa 1976) 2007 Jan;32(1):55-62

Department of Orthopaedics, University of British Columbia and Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada.

Study Design: An in vitro biomechanical study to quantify 3-dimensional kinematics of the lumbar spine following facet arthroplasty.

Objectives: To compare the multidirectional flexibility properties and helical axis of motion of the Total Facet Arthroplasty System (TFAS) (Archus Orthopedics, Redmond, WA) to the intact condition and to posterior pedicle screw fixation.

Summary Of Background Data: Facet arthroplasty in the lumbar spine is a new concept in the field of spinal surgery. Read More

View Article and Full-Text PDF
January 2007

In vitro, biomechanical comparison of an anterior lumbar interbody fusion with an anteriorly placed, low-profile lumbar plate and posteriorly placed pedicle screws or translaminar screws.

Spine (Phila Pa 1976) 2005 Aug;30(16):1846-51

Orthopaedic Biomechanics Lab, Minneapolis Medical Research Foundation, Minneapolis, MN, USA.

Study Design: An in vitro biomechanical comparison of anteriorly placed lumbar plates, pedicle screws, and translaminar screws in the anterior lumbar interbody fusion (ALIF) setting.

Objectives: To determine whether an anteriorly placed lumbar plate reduces the flexibility in terms of neutral zone and range of motion of a simulated ALIF, and to compare this reduction in flexibility to that provided by posteriorly placed pedicle screws and translaminar screws.

Summary Of Background Data: Pedicular and translaminar facet fixation add stability and increase fusion rates, compared with ALIF alone. Read More

View Article and Full-Text PDF

Biomechanical analysis of rigid stabilization techniques for three-column injury in the lower cervical spine.

Spine (Phila Pa 1976) 2005 Apr;30(8):915-22

VKV Amerikan Hastanesi, Department of Neurosurgery, Istanbul, Turkey.

Study Design: Comparison of nondestructive multidirectional flexibility in groups of specimens receiving two different posterior instrumentation constructs with or without anterior plating.

Objective: To compare stability after a three-column injury stabilized posteriorly by lateral mass screws-rods at C5-C6 and pedicle screws-rods at C7 ("LLP") or by pedicle screws-rods at C5-C6-C7 ("PPP"), and to compare posterior, anterior, and combined anterior-posterior fixation.

Summary Of Background Data: Pedicle screws resist pullout better than lateral mass screws, but little research has compared the stability of pedicle screws to that of lateral mass screws used within constructs. Read More

View Article and Full-Text PDF

Biomechanical comparison of anterior cervical plating and combined anterior/lateral mass plating.

Spine J 2001 May-Jun;1(3):166-70

Spinal Biomechanics Research Laboratory, Barrow Neurological Institute, 350 W. Thomas Road, Phoenix, AZ 85013, USA.

Background Context: Previous studies showed anterior plates of older design to be inadequate for stabilizing the cervical spine in all loading directions. No studies have investigated enhancement in stability obtained by combining anterior and posterior plates.

Purpose: To determine which modes of loading are stabilized by anterior plating after a cervical burst fracture and to determine whether adding posterior plating further significantly stabilizes the construct. Read More

View Article and Full-Text PDF

A biomechanical comparison between anterior and transverse interbody fusion cages.

Spine (Phila Pa 1976) 2001 Jun;26(12):E261-7

Division of Neurosurgery, University of Iowa, Iowa City Veterans Affairs Medical Center, Iowa City, Iowa, USA.

Study Design: Human cadaveric lumbar spines underwent placement of threaded fusion cages (TFCs) in either an anterior or transverse orientation. Spines underwent load testing and angular rotation measurement in the intact state, after diskectomy, after cage placement, and after fatiguing. Angular rotations were compared between cage orientations and interventions. Read More

View Article and Full-Text PDF

Load-sharing between anterior and posterior elements in a lumbar motion segment implanted with an artificial disc.

Spine (Phila Pa 1976) 2001 Mar;26(6):E122-9

Iowa Spine Research Center, Departments of Biomedical Engineering andOrthopaedics, University of Iowa, Iowa City, Iowa, USA.

Study Design: A nonlinear three-dimensional finite element model of the osteoligamentous L3-L4 motion segment was used to predict changes in posterior element loads as a function of disc implantation and associated surgical procedures.

Objectives: To evaluate the effects of disc implantation on the biomechanics of the posterior spinal elements (including the facet joints, pedicles, and lamina) and on the vertebral bodies.

Summary Of Background Data: Although several artificial disc designs have been used clinically, biomechanical data-particularly the change in loads in the posterior elements after disc implantation-are sparse. Read More

View Article and Full-Text PDF

The effect of anterior osteophytes and flexural position on thoracic trabecular strain.

Spine (Phila Pa 1976) 2001 Jan;26(1):22-6

Department of Orthopaedic Surgery, Tokai University School of Medicine, Kangawa, Japan.

Study Design: Compressive and shear trabecular strains were evaluated using six cadaveric thoracic spines that included anterior osteophytes. The treatments were divided into three groups: 1) osteophytes intact and the specimen in the neutral position, 2) osteophytes removed and the specimen in the neutral position, and 3) osteophytes removed and the specimen with 5 degrees of additional flexion.

Objectives: To investigate the influence of osteophytes and flexural position on vertebral trabecular strain during axial compression. Read More

View Article and Full-Text PDF
January 2001

Spinal stability with anterior or posterior ray threaded fusion cages.

J Neurosurg 2000 Jul;93(1 Suppl):102-8

Department of Biomedical Engineering, University of Iowa College of Medicine and Veterans Administration Medical Center, Iowa City 52242, USA.

Object: The authors conducted a study to determine if the rigidity supplied to the spine by posterior placement of the Ray threaded fusion cage (TFC) is further enhanced by the placement of pedicle screws and, additionally, if bilateral anteriorly placed TFCs render the spine more rigid than a single anteriorly placed TFC.

Methods: Ten human cadaveric spinal specimens (L2-S1) were affixed within a testing frame. Loads of 1. Read More

View Article and Full-Text PDF