Abstract: Maximum length measurement of the tibia has been found to be variable both in description and implementation. Historically, the literature often excludes the intercondylar eminences from the tibia in metric analysis. This paper explores the quantitative effects of inclusion or exclusion of the eminences on the maximum length measure across ancestral population, age and sex in five human adult populations of American Whites and Blacks, two Native American samples, and East Asians. A Tukey’s post hoc comparison was employed to determine the overall effect of inclusion the intercondylar eminences has on metric assessment of the tibia. Results show no significant effect on comparative analysis of the tibia by age or sex. However, the difference between sample means by ancestry is significant (p < 0.0001). These results pose interesting questions concerning the morphological differences between ancestral groups. This investigation prompts further study of population variation of the human knee.