Changes in long bone diaphyseal strength with horticultural intensification in west-central Illinois.

This study examines changes in long bone diaphyseal strength in west-central Illinois from the Middle Woodland through the Mississippian periods. Significant differences occur between the Middle Woodland and the Late Woodland periods, at the time when use of native seed crops intensifies. In females, both humeral and femoral strength increases, which may be related to their role in growing and processing these crops. In males, right arm strength declines, which may be tied in part to the replacement of the atlatl by the bow. Fewer significant changes occur between the earlier and later Late Woodland periods, at the time when maize is introduced as a dietary staple, possibly because maize is at first grown as only one of a series of other starchy seeds. Finally, in the Mississippian period, when maize use intensifies, female left arm strength declines. This may be because maize is easier to process than native seeds, or it may reflect innovations in processing technology in the Mississippian period. External dimensions and shape indices, in part, reflect the trends seen in biomechanical strength. Comparisons are made to similar studies in other regions.