The tackle made by Marcus Trufant caused Lewis' head to accelerate in his helmet at 30 to 60 g's, according to a study done by Virginia Tech. Researchers at VT collect data with the Head Impact Telemetry System, which plants sensors and wireless transmitters in helmets. Stefan Duma, director of the university's Center for Injury Biomechanics, states, "We see 100-g impacts all the time, and several over 150 g's."
