Comparing FE human body model rib geometry to population data

Area of Science:

• Biomechanics and Computational Modeling
• Human Anatomy and Injury Assessment

Background:

• Finite element human body models (HBMs) are crucial for assessing injury risk in impact simulations.
• Accurate representation of thoracic structures, especially ribs, is vital for reliable biomechanical modeling and injury prediction.

Purpose of the Study:

• To evaluate the geometric accuracy of ribs in five widely used HBMs against population-wide rib geometry data.
• To identify specific areas of geometric discrepancy in rib global shape, cross-sectional properties, and cortical bone thickness.

Main Methods:

• Compared rib geometry from five HBMs (GHBMC M50, THUMS M50, GHBMC F05, THUMS F05, VIVA F50) to population reference data.
• Utilized a parametric global shape model to assess rib shape parameters against expected values.
• Analyzed cross-sectional area, inertial moments, and cortical bone thickness along the length of HBM ribs.

Main Results:

• Several male and female HBMs exhibited rib shape parameters significantly deviating (outside 1SD) from population expectations.
• HBM ribs generally showed larger cross-sectional areas compared to average population values (0.9-1.7SDs).
• Models with constant cortical bone thickness overestimated bone content, and discrepancies were most pronounced at the sternal end of ribs.

Conclusions:

• Current HBM rib geometry often deviates from expected population data, impacting biofidelity.
• Discrepancies in rib geometry, particularly at the sternal end, correlate with regions prone to fracture.
• Findings provide a basis for prioritizing improvements in HBM rib geometry for enhanced injury prediction accuracy.