Sexual Dimorphism of Inter-acromial Length: An Autopsy Based Study

Human anatomical variations, influenced by genetics, ethnicity, and environmental factors, play a crucial role in forensic identification. This study evaluates the reliability of inter-acromial length (IAL) as a sex-determining anthropometric parameter in forensic cases. Conducted at Shaheed Hasan Khan Mewati Government Medical College, Nalhar, the prospective study analyzed 100 postmortem cases (68 males, 32 females) aged ≥20 years, excluding those with deformities, trauma, or decomposition. IAL was measured using a sliding caliper between the acromial processes of the scapulae. Statistical analysis revealed a significant sex-based difference in mean IAL (males: 32.5 cm, females: 27.6 cm; p < .01). Receiver Operating Characteristic (ROC) analysis demonstrated strong diagnostic accuracy (AUC = 0.891), with an optimal IAL cut-off of 28.60 cm yielding 86.8% sensitivity, 78.1% specificity, and 84% overall accuracy. Positive and negative predictive values were 89.4% and 73.5%, respectively, supporting IAL’s utility in sex estimation. The findings align with sexual dimorphism principles, where broader male shoulders contribute to higher IAL values. Comparative analysis with prior studies confirmed IAL’s consistency as a sex predictor, though population-specific variations necessitate further validation. The study concludes that IAL is a practical, non-invasive tool for forensic sex determination, particularly in fragmented remains or mass disasters, complementing traditional methods. Future research should explore multiparameter models to enhance accuracy across diverse populations.