Thousands of college football players began competing around the United States this week, but with the thrill of the new season comes new data on the risks of taking the field. A new study reports that running backs and quarterbacks suffer the hardest hits to the head, while linemen and linebackers are hit on the head most often. The researchers measured head blows during games and practices over three seasons at Brown University, Dartmouth College, and Virginia Tech.

The study, led by Joseph J. Crisco, professor of orthopaedics in the Warren Alpert Medical School of Brown University and director of the bioengineering laboratory at Rhode Island Hospital, documented 286,636 head blows among 314 players in the 2007-09 seasons. ...

Crisco devised the algorithm that Simbex's Head Impact Telemetry System uses to measure head impacts. ...

Although Crisco's analysis is still underway, his insights into head impact exposure led him and co-author Richard Greenwald, a Dartmouth engineer, to write a commentary earlier this year in Current Sports Medicine Reports, in which they argued that intentional use of the head in sports must be curbed.