Table 3. Cross-sectional properties of femoral 50% sections of OH80 and KNM-ER 1808 (Homo erectus).

Specimen	CA	MA	TA	%CA	IX	IY	J
OH 80-12*	492	35	526	93.5	21.763	22.161	43.924
KNMER 1808	478	73	551	86.8	20.813	27.251	48.064

CA, cortical area; MA, medullary area; TA, total periosteal area; %CA, [(CA/TA) · 100); Ix, second moment of area about X (ML) axis (AP bending rigidity); Iy, second moment of area about y (AP) axis (ML bending rigidity); J, polar second moment of area. Areas in mm², second moments of area in mm⁴.

^*Measurements taken directly on the proximal break of the shaft at the mid-section.