Head Injury Criterion — HIC — is the most comprehensive single metric for evaluating traumatic brain injury risk from falls onto athletic surfaces. It appears alongside Gmax in field certification requirements and independent test reports, yet it is less frequently understood by field owners, specifiers, and procurement teams.
HIC is not a simpler version of Gmax, nor is it interchangeable with it. The two metrics measure different aspects of the same impact event — and a field can produce an acceptable Gmax while still generating a concerning HIC value. Understanding the difference between the two, and why both matter, is essential for anyone responsible for specifying, procuring, or managing a synthetic turf field.
