| Compressive force magnitude and intervertebral joint flexion/extension angle influence shear failure force magnitude in the porcine cervical spine. | |
| | |
MedLine Citation:
|
PMID: 22196209 Owner: NLM Status: Publisher |
Abstract/OtherAbstract:
|
Despite the findings that peak anterior shear load is highly correlated with low-back pain reporting, very little research has been conducted to determine how vertebral shear injury potential is influenced. The current study quantified the combined effects of vertebral joint compression and flexion/extension postural deviation from neutral on ultimate shear failure. Ninety-six porcine cervical specimens (48C3-C4, 48C5-C6) were tested. Each specimen was randomly assigned to one of twelve combinations of compressive force (15%, 30%, 45%, or 60% of predicted compressive failure force) and flexion/extension postural deviation (extended, neutral, or flexed). Vertebral joint shear failure was induced by applying posterior shear displacement of the caudal vertebra at a constant rate of 0.15mm/s. Throughout shear failure tests, vertebral joint kinematics were measured using an optoelectronic camera and a series of infrared light emitting diodes while shear force was measured from load cells rigidly interfaced in series with linear actuators that applied the shear displacement. Measurements of shear stiffness, ultimate force, displacement, and energy stored were made from the force-displacement data. Compressive force and postural deviation demonstrated main effects without a statistically significant interaction for any of the measurements. Shear failure force increased by 11.1% for each 15% increment in compressive force (p<0.05). Postural deviation from neutral impacted ultimate shear failure force by a 12.8% increase with extension (p<0.05) and a 13.2% decrease with flexion (p<0.05). Displacement at ultimate failure was not significantly altered by either compressive force or postural deviation. These results demonstrate that shear failure force may be governed by changes in facet articulation, either by postural deviation or by reducing vertebral joint height through compression that alter the moment arm length between the center of facet contact pressure and the pars interarticularis location. However, objective evidence of this alteration currently does not exist. Both compression and flexion/extension postural deviation should be equally considered while assessing shear injury potential. |
| | |
Authors:
|
Samuel J Howarth; Jack P Callaghan |
Related Documents
:
|
20120259 - Visual reaction time and size constancy. 14263779 - Adaptation to prismatically rotated visual fields. 11288829 - Distance discrimination during active electrolocation in the weakly electric fish gnath... 1635859 - Determinants of the perception of sagittal motion. 2726409 - Distance perception as a function of photographic area of view. 15376929 - Reconstruction of sculpture from its profiles with unknown camera positions. 8169939 - Representations of ecg--late potentials in the time frequency plane. 7178799 - Power spectral analysis of auditory brain stem responses to pure tone stimuli. 22280729 - Sounds of indo-pacific humpback dolphins (sousa chinensis) in west hong kong: a prelimi... |
Publication Detail:
|
Type: JOURNAL ARTICLE Date: 2011-12-21 |
Journal Detail:
|
Title: Journal of biomechanics Volume: - ISSN: 1873-2380 ISO Abbreviation: - Publication Date: 2011 Dec |
Date Detail:
|
Created Date: 2011-12-26 Completed Date: - Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 0157375 Medline TA: J Biomech Country: - |
Other Details:
|
Languages: ENG Pagination: - Citation Subset: - |
Copyright Information:
|
Copyright © 2011 Elsevier Ltd. All rights reserved. |
Affiliation:
|
Canadian Memorial Chiropractic College, Toronto, Ontario, Canada. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: The impact of the host on fungal infections.
Next Document: A Statistical Mechanical Model of Cholesterol/Phospholipid Mixtures: Linking Condensed Complexes, Su...