@article{ref1,
title="Muscle tetanus and loading condition effects on the elastic and viscous characteristics of the thorax.<br />",
journal="Traffic injury prevention",
year="2003",
author="Kent, Richard W. and Bass, Cameron R. and Woods, William and Sherwood, Christopher P. and Madeley, N. J. and Salzar, Robert and Kitagawa, Yuichi",
volume="4",
number="4",
pages="297-314",
abstract="Thoracic deformation under an applied load is an  established indicator of injury risk, but the force required to achieve an  injurious level of deformation currently is not understood adequately. This  article evaluates how two potentially important factors, loading condition and  muscle tensing, affect the structural response of the dynamically loaded thorax.  Structural models of two human cadaver thoraxes and two porcine thoraxes were  used to quantify the effects. The human cadavers, which represent anthropometric  extremes, were subjected to anterior loading from (1) a 5.1-cm-wide belt  oriented diagonally (i.e., seatbelt-like loading), (2) a 15.2-cm-diameter rigid  hub, and (3) a 20.3-cm-wide belt oriented laterally (i.e., a distributed load).  A structural model having the mathematical formulation of a quasilinear  viscoelastic material model was used to model the elastic and viscous response,  with ramp-hold tests used to determine the model coefficients. The effect of  thoracic musculature was assessed using similar ramp-hold tests on the porcine  subjects, each with and without forced muscle contraction. Even maximally  contracted thoracic musculature is shown to have a minimal effect on the  response, with similar elastic and viscous characteristics exhibited by each  subject regardless of muscle tone. The elastic response is shown to be  approximately a factor of three stiffer for diagonal belt loading and for this  distributed loading condition than for the hub loading, indicating that the  response is influenced most by the particular anatomical structures that are  engaged and, secondarily, by the area of load application. Specifically,  shoulder involvement is shown to have a strong influence. The force relaxation  is found to be pronounced, but insensitive to the loading condition, with  long-time force relaxation coefficients (G( infinity )) in the range of 0.1 to  0.3. The findings of this study provide restraint-specific guidelines for the  force-deflection characteristics of both physical and computational thoracic  models.",
language="",
issn="1538-9588",
doi="",
url="http://dx.doi.org/"
}