Helmets certified by today’s linear acceleration based criteria are credited with all-but eliminating fatal focal injury in sports. Brain injuries may still occur where there is absence of severe focal injury leading to discussions regarding how helmet assessment methods might move towards the inclusion of impact parameters relevant to brain injury. To first understand the relationship between kinematic measures and computed brain strain, we conducted hundreds of impacts using the 50th percentile Hybrid III head-neck equipped with an ice hockey helmet. We then input the three-dimensional impact kinematics to a finite element brain model called the Simulated Injury Monitor (SIMon) to compute brain strain measures including the cumulative strain damage measure (specifically CSDM-15). Resultant change in angular velocity (ΔωR) was the single best kinematic predictor for CSDM-15 and better predicted strain than the current helmet certification metric, peak g. The best two-variable model included peak angular acceleration and ΔωR, though an efficient model for predicting CSDM-15 that included at least one linear and one angular kinematic included two variables:​ peak g and ΔωR. A preliminary metric based on peak g and ΔωR was presented and a possible threshold limit was proposed.