TY - JOUR
T1 - Experimentally tested computer modeling of stress fractures in rats
AU - Stern-Perry, Michal
AU - Gefen, Amit
AU - Shabshin, Nogah
AU - Epstein, Yoram
PY - 2011/4/1
Y1 - 2011/4/1
N2 - Experimentally tested computer modeling of stress fractures in rats. J Appl Physiol 110: 909 -916, 2011. First published February 17, 2011; doi:10.1152/japplphysiol.01468.2010.-The objective of this study was to develop a finite-element (FE) modeling methodology for studying the etiology of a stress fracture (SF). Several variants of three-dimensional FE models of a rat hindlimb, which differed in length or stiffness of tissues, enabling the analyses of mechanical strains and stress in the tibia, were created. We compared the occurrence of SFs in an animal model to validate locations of peak strains/stresses in the FE models. Four Sprague-Dawley male rats, age ̃7 wk, were subjected to mechanical cyclic loads of 1.2 Hz and ̃6 N, which were delivered to their hindlimb for 30 min, 3 times/wk, up to 12 wk, by using a specially designed apparatus. The results showed that 1) FE modeling predicted the maximal strains/stresses (̃220,0 με and ̃29 MPa, respectively) between the mid- and proximal thirds of the tibia; 2) in a longer shin, greater and more inhomogeneous tensile strains/stresses were evident, at the same location; 3) anatomical variants in shin length influenced the strain/ stress distributions to a greater extent with respect to changes in mechanical properties of tissues; and 4) bone stiffness was more dominant than muscle stiffness in affecting the strain/stress distributions. In the animal study, 35,000 loading cycles were associated with the formation of a SF. The location of the identified SF in the rat limb verified the FE model. We find the suggested model a valuable tool in studying various aspects of SFs.
AB - Experimentally tested computer modeling of stress fractures in rats. J Appl Physiol 110: 909 -916, 2011. First published February 17, 2011; doi:10.1152/japplphysiol.01468.2010.-The objective of this study was to develop a finite-element (FE) modeling methodology for studying the etiology of a stress fracture (SF). Several variants of three-dimensional FE models of a rat hindlimb, which differed in length or stiffness of tissues, enabling the analyses of mechanical strains and stress in the tibia, were created. We compared the occurrence of SFs in an animal model to validate locations of peak strains/stresses in the FE models. Four Sprague-Dawley male rats, age ̃7 wk, were subjected to mechanical cyclic loads of 1.2 Hz and ̃6 N, which were delivered to their hindlimb for 30 min, 3 times/wk, up to 12 wk, by using a specially designed apparatus. The results showed that 1) FE modeling predicted the maximal strains/stresses (̃220,0 με and ̃29 MPa, respectively) between the mid- and proximal thirds of the tibia; 2) in a longer shin, greater and more inhomogeneous tensile strains/stresses were evident, at the same location; 3) anatomical variants in shin length influenced the strain/ stress distributions to a greater extent with respect to changes in mechanical properties of tissues; and 4) bone stiffness was more dominant than muscle stiffness in affecting the strain/stress distributions. In the animal study, 35,000 loading cycles were associated with the formation of a SF. The location of the identified SF in the rat limb verified the FE model. We find the suggested model a valuable tool in studying various aspects of SFs.
KW - Bone
KW - Finite element
KW - Overuse injury
KW - Rodent
KW - Tibia
UR - http://www.scopus.com/inward/record.url?scp=79954591730&partnerID=8YFLogxK
U2 - 10.1152/japplphysiol.01468.2010
DO - 10.1152/japplphysiol.01468.2010
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AN - SCOPUS:79954591730
SN - 8750-7587
VL - 110
SP - 909
EP - 916
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 4
ER -