As Heads Collide, Helmet Measures Impacts

Feb. 1, 2008 -- This Superbowl Sunday, heads will knock.

And new research using high-tech helmets is showing that even low-impact head hits can cause brain injuries. The results, which challenge some conventional views about head trauma, could lead to safer practice sessions, improve sports equipment, and help physicians better understand injuries such as concussions.

Players who look like they have been hit really hard aren't necessarily the ones who will sustain the most brain damage, said Kevin Guskiewicz, professor of exercise and sport science and director of the Sports Medicine Research Laboratory at the University of North Carolina, Chapel Hill.

"There's no relationship between the magnitude of the impact and the clinical outcome," he said.

Guskiewicz and his team conducted their research using a sensor-imbedded helmet called the Revolution IQ HITS, distributed by Rosemont, Ill.-based Riddell. The helmet, which was made commercially available last fall and sells for $999, contains six sensors that measure acceleration.

Placed at the crown of the helmet, as well as the left side, right side, face and back, the sensors measure in real time the amount of g-force a player's head experiences at impact, where the hit occurs, and where it comes from.

The sensors communicate the force measurements wirelessly by way of a radio frequency to a receiver on the sidelines. The data is then automatically uploaded to a computer program that tracks impact location and magnitude.

G-force, which is a measure of acceleration against the Earth's gravitational pull, is something astronauts or jet pilots experience. But even in car crash tests at 25 m.p.h., dummies hit windshields at 100g.

Football players are no different. They commonly experience hits at forces between 50g and 100g. Previous research suggested that concussions likely resulted at forces above 75g, but the new study indicates otherwise.