This document specifies test methods for measuring the Head Injury Criterion (HIC) of sports surfaces. Two different methods are specified. In Procedure A, a series of tests are undertaken from differing drop heights and the HIC values are plotted, and the Critical Fall Height determined. In Procedure B, a series of tests are made at a fixed drop height and the mean value of HIC is calculated. This test method is primarily intended for use on synthetic turf sport surfaces. It may be carried out in a laboratory on test specimens or in situ on installed sports surfaces. NOTE Annex A contains an indicative test method where a single test is made at each drop height and an indicative value of HIC is calculated. This test method can also be used on other forms of sports surfacing that may be intended to provide impact protection against head impacts.