Traumatic brain injury (TBI) is a severe health problem for society. Meanwhile, predicting and preventing TBI remains challenging in the field. Peak rotational velocity was demonstrated to be correlated to brain strain responses, and hence could potentially serve as a good predictor for brain injury. Brain strain was influenced by impact direction, deceleration and impact loading curve shapes. Wearing helmets is an effective way to protect the brain from TBI, but there lacks a study on evaluating helmet performance based on both energy absorption and brain strain response, which this study addressed. Interestingly, helmet shell absorbed around half of the energy, followed by interior foams close to impact locations. Facemask also affected brain strain response as it changed both the rigidity and inertia of the helmet.