A system is provided for assessing heard injury criterion (HIC) by analyzing signals received from sensors of a sensor array to calculate an impact force on an impact area, determine the linear acceleration based on the impact force and mass of the wearer's head. HIC values are calculated within a variable duration sliding window across a time period within which an impact occurs based on the integral of linear acceleration for the time period of the window, to determine a maximal HIC which is converted to a biofeedback signal.