Olecranon Fossa


Shape Simulator

Metric Pattern Analysis

                

Use shape simulator to recreate the olecranon fossa of a humerus you are analysing. Change triangularity and concavity until they closely resemble your individual's shape as much as possible. Below the LDA model gives you the probability of your individual being a male or a female based on the visual criteria you simulated. Here, the method works like a morphoscopic/visual scoring method, but in a continuous scale.


Analysis Report
Probabilistic Result

Linear Discriminant 1

Predicted Class
Shape Simulator

Best separation occurs with PC3 and PC5 for our sample, with the analyses performed, and we provide a model in the Shape Simulator tab to work with these sex-correlated variables.

Here we allow you to interact with all the other PCs so you can better understand what kind of information a PCA actually extracts from shape data. As you will see, those are all very abstract shape transformations, that describe the variability on the dataset, but not necessarily what would better help you describe/analyse a particular problem.

Disclaimer


This decision support system is freely provided as an aid for profiling skeletal material. Osteomics has no responsibility for its ultimate use or misuse. While Osteomics tries to ensure the software is theoretically grounded and statically accurate, we provide no warranty and make no specific claims as to its performance or its appropriateness for use in any particular situation. If a paper is available for any of our tools, please read it before applying the method. Always keep in mind: you are the expert, these tools are just decision support systems. They do not have the final word.



Reference


Outline Shape Analysis on the Trochlear Constriction and Olecranon Fossa of the Humerus: Insights for Sex Estimation and a New Computational Tool

Saskia Ammer, João d'Oliveira Coelho, Eugénia M. Cunha

Available at DOI:10.1111/1556-4029.14096


Abstract

Sex estimation through visual analysis of the distal humerus can contribute to establishing the biological profile of an unidentified skeletal individual. Using statistical shape modeling, the trochlear constriction open curves and olecranon fossa closed outlines of 151 humeri were digitized and analyzed. The shape configurations exhibited strikingly different degrees of sexual dimorphism when evaluated using linear discriminant analysis with leave-one-out cross-validation. The trochlear constriction performed poorly, correctly classifying 63.6% of the individuals. However, the olecranon fossa showed high sexual dimorphism, presenting a 94.0% accuracy. A simpler model using only two principal components was also generated. While the accuracy is slightly inferior (88.1%), it has the advantage of being constrained to bidimensional components that were translated into morphoscopic variables within a simulator interface. This allowed us to implement the method through a web-application that does not require users to be trained in landmark digitization or have knowledge of geometric morphometrics.


Dataset details

Model developed from a subsample of an osteological collection of a portuguese population, for more info click here

- 80 female and 71 male distal humeri


Keywords

Forensic science, forensic anthropology, outline shape analysis, web application, sex estimation, distal humerus