Hand Geometry in Forensic Application: Estimating Hand Length Derived from Phalangeal Lengths

The human hand plays a significant role in the identification of sex and identity, especially when partial remains are recovered from crime scenes. This study explores the importance of using digital phalanx lengths to estimate Hand Length (HL), examine sexual dimorphism, and identify the most reliable biometric predictors of sex in the Bengali population. This study collected bilateral palm impressions from 100 university-level students (50 men, 20.18 ± 1.38; 50 women, 19.61 ± 1.48) from North 24 Pargana District. Different phalanx segments were measured and correlated with HL using regression models.

The independent t test revealed that all the middle and distal phalangeal lengths were was significantly higher in men (P < .01). Except for the Proximal Phalanges of the Middle (right hand), Ring (right hand), and Little (both left and right hands) fingers, all the proximal phalangeal lengths were found significantly higher (P < .01) in men than in women. Furthermore, sexual dimorphism was observed, with men showing significantly longer palmar lengths than women (P < .05). Regression analysis revealed that Middle Phalanx of Ring Finger/D4 (LM) in men, and Proximal Phalanx of Index Finger/D2 (CD) in women show the highest predictive value in estimating HL, with statistically significant R² values (P < .05). However, the estimated equation remained consistent across both hands, thereby supporting the literature and emphasising the need for a specific hand-geometry-based dataset.

This study therefore confirms the reliability of hand geometry for forensic identification, serves as an accurate sex predictor in cases with partial prints, and highlights the need for more population-specific biometric data.