Do nonheader impacts result in higher linear acceleration compared to purposeful headers in collegiate women's soccer players?
Unanticipated nonheader impacts cause higher linear accelerations than purposeful headers but occur infrequently, potentially not adding substantially to cumulative exposure.
Nonheader impacts, including head-to-head impacts and unintentional deflections, resulted in higher mean linear accelerations than purposeful headers, including shots, clears, and passes, but occurred infrequently on the field. Therefore, these unanticipated impacts may not add substantially to an athlete's cumulative exposure, which is a function of both frequency and magnitude of impact.
Lamond et al. (Fri,) studied this question.