Black bear femoral porosity decreases and mechanical properties increase with age despite annual periods of disuse (hibernation)

Meghan E. McGee, Keith W. Magic, Danielle L. Miller, Aaron J. Maki, Seth W. Donahue

Research output: Contribution to journalArticle

9 Scopus citations


Inactivity causes bone loss, and a remobilization period that is 2-3 times longer than the disuse period is required to recover lost bone. Black bears (Ursus americanus), however, experience annual disuse (hibernation) and active periods that are approximately equal in length, but maintain bone material properties with age. Here, the effects of annual hibernation periods on whole bone properties were investigated. This study shows that mineral, geometrical and whole bone mechanical properties increase with age in black bear femurs, whereas porosity decreases with age. These results provide further support that black bears possess a biological mechanism to avoid disuse osteoporosis.

Original languageEnglish (US)
Pages (from-to)1942-1952
Number of pages11
JournalEngineering Fracture Mechanics
Issue number12
Publication statusPublished - Aug 1 2007
Externally publishedYes



  • Black bear
  • Cortical bone
  • Disuse osteoporosis
  • Mechanical properties
  • Structural properties

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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