Metric Input
Fill the numeric input boxes above with the measurements (in mm) you collected. Anatomical descriptions of the metrics are available in the upper tab menu.
Model Summary
///////// Calcaneal measurements
CM1 - Maximum length ▁▂▇▅▁
Projected line from the most posterior point of the tuberosity of the calcaneus to the most anterior/superior point of the cuboidal facet (Martin, 1928).
CM1a - Length ▁▂▇▅▁Projected line from the most posterior point of the tuberosity of the calcaneus to the mid-point of the cuboidal facet (Martin, 1928)
CM2 - Load arm width ▁▂▇▆▂Transverse projected line perpendicular to the long axis from the most lateral point of the posterior articular surface, to the most medial point of the sustentaculum tali (Martin, 1928).
CLAL - Load arm length ▁▃▇▅▁Projected line from the most posterior point of the posterior articular surface for the talus, to the most anterior/superior point of the cuboidal facet (Slal, according to Steele, 1976).
CM4 - Body height ▃▇▆▃▁Projected height from the most inferior point of the tuberosity of the calcaneus to the most inferior point of the body of the calcaneus (Martin, 1928).
CM5 - Body length ▁▂▇▆▂Projected line from the most superior point of the tuber calcanei to the most distally point of the posterior facet of the calcaneus, measured parallel to the sagittal axis of the bone (Martin, 1928).
CMBH - Maximum body height ▁▇▇▅▂Greatest projected height of the calcaneus, and measured from the most inferior point of the tuberosity of the calcaneus to the most superior point of the posterior facet of the calcaneus (Smh, according to Steele, 1976).
CM7 - Tuber calcanei length ▂▇▇▆▁Greatest projected height of the tuber calcanei, measured from the most superior point of the tuber calcanei to the most inferior point of the Processus medialis tuberis calcanei (Martin, 1928).
CM8 - Tuber calcanei width ▁▂▇▅▂Projected line laterally/medially of the tuber calcanei, perpendicular to the sagittal plane (Martin, 1928).
Calcaneus in lateral view
Calcaneus in superior view
///////// Talar measurements
TM1 - Maximum length ▁▃▇▅▂
From the M. flexor hallucis longus groove to the most anterior point on the head measured parallel to the sagittal axis of the trochlea (Martin, 1928).
TM2 - Width of the talus ▁▅▇▇▂Maximum projected line laterally/medially perpendicular to the sagittal plane. The lateral point is the most lateral point on the articular surface for the lateral maleolus and the line generally bisects the articular surface for the tibia slightly forward of the midpoint (Martin, 1928).
TM3 - Body height ▁▂▇▅▁Height of the body along the sagittal plane, taking above the articular surface for the tibia. The measurement is taken by placing the talus on a flat surface (Martin, 1928).
TM3a - Maximum body height ▁▃▇▅▁Maximum height of the body in an inferior/medially perpendicular to the sagittal plane. The measurement is taken by placing the talus on a flat surface and then determining the most superior point of the articular surface for the tibia. The superior point is generally along the medial rim of the facet (Martin, 1928).
TM4 - Trochlear length ▁▅▇▅▁Maximum length of the trochlear articular surface on the midline measured parallel to the sagittal axis of the trochlea (Martin, 1928).
TM5 - Trochlear width ▂▇▇▃▁From the mid-lateral edge of the trochlea to its mid-medial edge measured perpendicular to the sagittal plane of the trochlea (Martin, 1928).
Talus in the superior view
Talus in anterior view.
///////// References
Martin R. 1928. Lehrbuch der Anthropologie. Stuttgart, Gustav Fischer Verlag.
Steele DG. 1976. The estimation of sex on the basis of the talus and calcaneus. American Journal of Physical Anthropology. Vol 45 : 581–588.
Hindfoot metric models for sex estimation
///////// Reference data:
Curate, F., d'Oliveira Coelho J, Silva, AM. 2021. CalcTalus – an online decision support system for the estimation of sex with the calcaneus and talus. Archaeological and Anthropological Sciences. Vol 13: 74. DOI: 10.1007/s12520-021-01327-y
///////// Classification Model:
Logistic Regressions and Support vector Machines
Abstract
Objectives: The estimation of biological sex is a primary source of information regarding unidentified skeletal individuals in bioarcheological and forensic contexts. This study aims to propose new metric standards for the estimation of sex using variables of the calcaneus and talus. An ancillary goal encompasses the creation of a web-based decision support system for the assessment of sex.
Materials and Methods: Six measurements from the talus and nine from the calcaneus were collected from 180 adult individuals (93 females; 87 males) belonging to the Coimbra Identified Skeletal Collection. Logistic regression (LR), support vector machines (SVM) and a decision-tree algorithm were employed to develop models for sex prediction.
Results: Univariable sectioning points generated with a decision-tree algorithm yielded an accuracy under cross-validation from 78.3% to 82.2% with talar measurements, and from 73.6% to 86.4% with calcanei variables. Systematic error ranged from 0.2% to 34.1%. Univariable and multivariable models, produced with LR and SVM, correctly predicted sex in 85.0 – 91.3% of cases (bias from 0.3 to 4.3%).
Discussion: Obtained cross-validated accuracies obtained with the new models are similar to earlier results on the subject. The performance of multivariable models predictive is substantially superior, hinting the relevance of population specific standards for sex estimation. The operationalization of these models in a free, user-friendly, web-application – CalcTalus – facilitates the probabilistic assessment of sex, providing performance metrics for the statistical templates.
///////// Keywords
sex estimation; biological profile; talus; calcaneus; decision support systems
Disclaimer
This decision support system is freely provided as an aid for profiling skeletal material. The authors hold no responsibility for its ultimate use or misuse. As creators we try to ensure that 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. Please read any research paper regarding this tool before applying it. Always keep in mind: you are the expert, this is just a decision support system.