On a basis of a method for muscle cross-sectional area estimation from cortical bone area that was previously developed (Slizewski et al. Anat Rec 2013; 296:1695–1707), we reconstructed muscle cross-sectional area at 65% of radius length for a sample of Neolithic human remains from the Linear Pottery Culture (ca. 5,700–4,900 years BC). Muscle cross-sectional area estimations for the Neolithic sample were compared to in vivo measurements from a recent human sample. Results demonstrate that the Neolithic individuals had larger muscle cross-sectional area relative to radius length than the contemporary humans and that their forearms were more muscular and robust. We also found significant differences in relative muscle cross-sectional area between Neolithic and recent children that indicate different levels of physical stress and isometric activities. Our results fit into the framework of studies previously published about the sample and the Linear Pottery Culture. Therefore, the new approach was successfully applied to an archaeological sample for the first time here. Results of our pilot study indicate that muscle cross-sectional area estimation could in the future supplement other anthropological methods currently in use for the analysis of postcranial remains. Anat Rec, 297:1103–1114, 2014. © 2014 Wiley Periodicals, Inc.