The Development of Population-Wide Descriptions of Human Rib and Rib Cage Geometry, wide rib cages

A novel parametric shape model of the human rib centroidal path using logarithmic spirals is presented, providing a more accurate and efficient fit than previous models of overall rib geometry, and it utilizes direct geometric properties such rib size, aspect ratio, and “skewness” in its parameterization. The development of population-wide descriptions of human rib and rib cage geometry by Sven Alan Holcombe Co-Chairs: Professor James B. Grotberg, Professor Stewart C. Wang Elderly individuals, obese individuals, and females all have greater risk of rib fractures and other associated thoracic injuries than younger mid-sized male adults in motor vehicle crashes. Differences in body morphology between these vulnerable populations and the subjects represented by physical or computational human body models is a potential source for this risk disparity, and efforts are required to quantify these differences in order to protect a wider population. We present a novel parametric shape model of the human rib centroidal path using logarithmic spirals. It provides a more accurate and efficient fit than previous models of overall rib geometry, and it utilizes direct geometric properties such rib size, aspect ratio, and “skewness” in its parameterization. The model was fitted to 21,124 ribs from 1000 adult CT scans, and regression analyses produced a flexible rib shape model to build ribs typical for any population of a given age, height, weight, and sex. Significant differences in rib shape were quantified across populations, and a new aging effect was uncovered whereby rib span and rib aspect ratio are seen to increase with age, producing characteristically shallower and flatter overall