LIVERPOOL, ENGLAND—Phys.org reports that researchers from the University of Liverpool fitted 24 men and 16 women with sensors measuring their range of motion, muscle contractions, oxygen consumption, and speed while working with tools with handles and tools without handles. The volunteers were asked to attempt to chop down a simulated tree and scrape fibers from a carpet with both types of tools. The study found that the men and women employed a greater range of motion and worked with more force when using tools with handles. Although crafting hafted tools takes more time and effort, the researchers determined that the payoff in work achieved outweighed the cost of the time and effort to make them. In their view, these benefits likely contributed to the invention and spread of hafted tool technology among hominins between 500,000 and 250,000 years ago. Read the original scholarly article about this research in Journal of the Royal Society Interface. To read about spearpoints found in South Africa that appear to have been hafted to shafts some 460,000 years ago, go to "The First Spears."