LATERAL AND POSTERIOR DYNAMIC BENDING OF THE MID-SHAFT FEMUR: FRACTURE RISK CURVES FOR THE ADULT POPULATION

The objective of this research was to develop injury risk functions for dynamic bending of the human femur in the posterior-to-anterior and lateral-to-medial loading directions. Forty -five experiments were done on human cadaver femurs using a dynamic three-point drop test setup. An impactor of 9.8 kg was dropped from 2.2 m for an impact velocity of 5 m/s. Five-axis load cells measured the support and impactor loads, and an in situ strain gage measured the failure strain and subsequent strain rate. All 45 tests resulted in mid-shaft femur fractures with oblique and comminuted wedge fractures as the most common fracture patterns. In the posterior-to-anterior bending tests the impactor loads were 4310 + or - 1040 N, and the reaction loads were 3780 + or - 930 N. In the lateral-to-medial bending tests the impactor loads were 4780 + or - 792 N, and the reaction loads were 4180 + or - 764 N. The difference between the sum of the reaction forces and the applied load is due to inertial effects. Femur cross-sectional area, maximum distance to the neutral axis, occupant mass, area moment of inertia, and occupant gender are found to be significant predictors of fracture tolerance. No significant difference is found for bone mineral density, loading direction, age, and leg aspect.

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  • English

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  • Accession Number: 00988084
  • Record Type: Publication
  • ISBN: 0768014468
  • Report/Paper Numbers: 2004-22-0002
  • Files: TRIS
  • Created Date: Mar 20 2005 12:00AM