Previous studies have measured the accuracy of sensors that measure head impact exposure. There is very little research, however, evaluating the proportion of false negatives through head impact sensors. A recent study featuring PISC Senior Scholar Kristy Arbogast, PhD, explores the proportion of false negatives in high school soccer head impact data. Male and female high school athletes were evaluated while wearing Smart-Impact Monitor-G impact sensors while playing competitive soccer games. Analysis of video footage from these competitive soccer games reveals 1,991 head contact exposures. In comparison, data from impact sensors records 55% of the head impacts witnessed on video. False negatives vary among the two genders. The team recommends that, based on the significant proportion of false negatives, future studies should consider video review a “complementary tool” when using head impact sensors.