Coordination strategies used in stone knapping
Article first published online: 28 JAN 2013
Copyright © 2013 Wiley Periodicals, Inc.
American Journal of Physical Anthropology
Volume 150, Issue 4, pages 539–550, April 2013
How to Cite
Rein, R., Bril, B. and Nonaka, T. (2013), Coordination strategies used in stone knapping. Am. J. Phys. Anthropol., 150: 539–550. doi: 10.1002/ajpa.22224
- Issue published online: 18 MAR 2013
- Article first published online: 28 JAN 2013
- Manuscript Accepted: 11 DEC 2012
- Manuscript Received: 29 FEB 2012
- European Union for the project “Handtomouth: a framework for understanding the archaeological and fossil records of human cognitive evolution”. Grant Number: 29065
- Fyssen Foundation and Volkswagenstiftung through the project “Towards a grammar of gestures: Evolution, Brain, and Linguistic Structures”. Grant Number: II/82175
- motor control;
Stone tool-use and manufacture is seen as an important skill during the evolution of our species and recently there has been increased interest in the understanding of perceptual-motor abilities underlying this skill. This study provides further information with respect to the motor strategies used during stone knapping. Kinematics of the striking arm were recorded in expert and novice knappers while producing flakes of two different sizes. Using Uncontrolled Manifold Analysis, the results showed that knappers structure joint angle movements such that the hammer trajectory variability is minimized across trials, with experts displaying significantly smaller variability compared with novices. Principal component analysis further revealed that a single component captures the complexity of the strike and that the strike is governed by movements of the elbow and the wrist. Analysis of movement velocities indicated that both groups adjusted movement velocities according to flake size although experts used smaller hammer, wrist, and elbow velocities in both flake conditions compared with novices. The results suggest that while the gross striking movement is easy to replicate for a novice knapper, it requires prolonged training before a knapper becomes attuned to the finer details necessary for controlled flaking. © 2013 Wiley Periodicals, Inc.