Angular dimensions and squatting facets in human dry tali of South Indian origin

The angular dimensions of the talus are indicative of its biomechanical role in load transmission. Squatting facets on the neck of the talus are indicative of habitual squatting. The primary objective of this study was to estimate the strength of association between the talar angles and the presence of squatting facets. The secondary objectives were to estimate the side differences in the angular dimensions and to assess the reliability of the method. One hundred and sixty dry tali of unknown sex were studied. The neck angle, vertical angle, torsion angle, trochlear surface angle and depth angle were measured using a photographic method. The presence of squatting facets was noted. The mean and standard deviation of those angles were 108.3 ± 5.23, 89.87 ± 3.97, 37.57 ± 5.62, 9.7 ± 3.3 and 156 ± 5.1 degrees respectively. The neck, vertical and depth angles were significantly higher on the left side. There were significant positive correlations between the neck and vertical angles, the neck and depth angles and the torsion and depth angles. Squatting facets were noted in 90 of the 160 (56%) of the tali. The torsion angle was significantly higher in tali with squatting facets. Intraobserver and inter-observer reliability of the methods were found to be good to excellent. The findings of this study indicate the factors that can possibly influence the magnitude of the talar angles. This data can be useful for designing talar prostheses and analyzing the biomechanical interface of the hind foot bones.