The effects of testing methods on the flexural fatigue life of human cortical bone

L. V. Griffin, J. C. Gibeling, R. B. Martin, V. A. Gibson, Susan M Stover

Research output: Contribution to journalArticle

14 Scopus citations


A flexural model of four-point bending fatigue that has been experimentally validated for human cortical bone under toad control was used to determine how load and displacement control testing affects the fatigue behavior of human cortical bone in three-point and symmetric four-point bending. Under load control, it was predicted that three-point bending produced no significant differences in fatigue life when compared to four- point bending. However, three-point bending produced less stiffness loss with increasing cycles than four-point bending. In four-point bending, displacement control was predicted to produce about one and a half orders of magnitude greater fatigue life when compared to load control. This prediction agrees with experimental observations of equine cannon bone tested in load and displacement control (Gibson et al., 1998). Displacement controlled three-point bending was found to produce approximately a 25% greater fatigue life when compared to load control. The prediction of longer fatigue life under displacement control may have clinical relevance for the repair of damaged bone. The model can also be adapted to other geometric configurations, including modeling of whole long bones, and with appropriate fatigue data, other cortical bone types.

Original languageEnglish (US)
Pages (from-to)105-109
Number of pages5
JournalJournal of Biomechanics
Issue number1
StatePublished - Jan 1999



  • Flexural fatigue
  • Load and deflection control
  • Microdamage

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine

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