The study found that human ribs undergo considerable plastic deformation prior to complete structural failure. The experiments conducted in this study indirectly support previous data that show anterior rib shafts are less stiff and less strong than the posterior regions of the same element. Because the reduced stiffness probably enhances energy absorption capacity in the anterior shaft, rib fractures can potentially occur in regions that are comparatively “strong” by standard biomechanical measures. Mode of failure varied with transverse, buckle, spiral, and “butterfly” fractures observed. The comparison of calculated stress with observed strain values suggest that experimental, rather than theoretical, approaches will be most productive in furthering an understanding of rib fractures in forensic contexts. In this study, isolated human ribs (n=8) were end-loaded until failure (fracture) occurred in order to determine local deformations (bone strain) prior to and during structural failure, the local of ultimate failure, and facture mode. Structural properties of the ribs were used to calculate theoretical stresses and determine whether such calculations could be used to predict the site of fracture. 3 tables, 5 figures, and 19 references