Population-specific equations for stature estimation using forearm bones: insights from Northeastern Thailand’s diverse ethnic landscape

Stature estimation from skeletal remains is crucial in forensic anthropology. This study aimed to develop population-specific equations for stature estimation using ulna and radius measurements in a Northeastern Thai population, a region known for its ethnic diversity. A total of 400 ulnae and 400 radii (200 of each bone from each sex) were analyzed from dry bone specimens. The study objectives were to: (1) develop and validate regression equations for stature estimation, (2) investigate sex differences in the relationship between forearm bone lengths and stature, and (3) compare the accuracy of these equations with existing formulae for other populations. Results showed significant sexual dimorphism in stature and bone lengths. The mean stature was 164.93 ± 6.54 cm for males and 156.21 ± 5.81 cm for females (<i>p</i> < 0.05). Positive correlations were observed between bone lengths and stature, with stronger correlations in males (ulna: r = 0.670; radius: r = 0.663) compared to females (ulna: r = 0.402; radius: r = 0.393). Regression equations for the pooled sample yielded coefficients of determination (r²) of 0.516 for ulna and 0.509 for radius. Sex-specific equations demonstrated higher accuracy, particularly for males. The standard error of estimate ranged from 4.87 cm to 5.35 cm across all equations. These findings suggest that ulna and radius lengths are reliable predictors of stature in the Northeastern Thai population, with sex-specific equations offering improved accuracy. This study contributes to the development of population-specific standards in forensic anthropology and highlights the importance of considering sexual dimorphism in stature estimation. The results have significant implications for forensic investigations and archaeological studies in the region.