No abstract

The goal of this study was to identify changes in acetabular morphology associated with the use of horses by Native Americans. Previous studies reported "elongate" acetabula in horseback-riding members of the Omaha and Ponca populations. Such a difference in acetabular shape is a potentially useful osteological marker of habitual horseback riding. This report compares acetabula of adult males from two Native American Arikara populations known to have differed substantially in their use of horses. Population samples were from separate sites in South Dakota: Larson (nonriding) and Leavenworth (riding). Outlines of acetabular rims were digitized and analyzed, using a simplified 12-point Fourier analysis. A Fourier series with six terms accurately described acetabular shape. Significant differences (P<0.10) between riding and nonriding populations were observed in two Fourier coefficients. Acetabula of riding Arikara were found to have smaller B(4) coefficients (P = 0. 061) and more positive B(2) coefficients (P = 0.080), indicating expanded anterior-superior borders relative to acetabula of non-riding Arikara.