Experimental evidence concerning spear use in Neandertals and early modern humans

Can a bimanual activity such as thrusting a spear during hunting produce bilateral asymmetries in the strength of the upper limbs? This question is important to arguments about the predatory capabilities of Neandertals and early modern humans. To address this question, we determined the magnitude and direction of reaction forces on the upper limbs during thrusting spear use. We collected lateral video records of eight adults thrusting an instrumented aluminum rod into a padded target. This "spear" was instrumented with two sets of four strain gauges placed at two positions along the shaft to register the force along the shaft and the distribution of those forces relative to the two limbs. From the gauge output and video we were able to calculate loads experienced by the trailing limb (holding the proximal spear) and the leading limb (holding the distal spear) as well as approximate bending moments along the trailing limb. The trailing limb provides a significantly greater portion of the force during spear impact and when the spear is held forcefully on the target. The loads on this limb at spear impact are twice body weight and the bending moments on the trailing humerus are large and appear to occur primarily in the parasagittal plane. These data, in combination with fossil humeral cross-sectional data and the lack of evidence for throwing spears among Eurasian Neandertals, suggest that previously documented humeral strength asymmetries in Eurasian Neandertals and early Upper Palcolithic Modern human males can be plausibly linked to spear thrusting. © 2002 Elsevier Science Ltd. All rights reserved.

Duke Scholars

Author Daniel Oliver Schmitt Evolutionary Anthropology

Author Steven E. Churchill Evolutionary Anthropology