a b s t r a c t The sport of American football is associated with a high incidence of concussion, which research has iden-tified may lead to long term neurological damage. As a result, it is important that protective technologies be developed to help mitigate the incidence of this type of brain trauma. This research examines how the design characteristics between different American football helmet models affect the linear and rotational acceleration responses as well as brain deformation metrics using a centric/non-centric impacting proto-col. The protocol involved impacting the helmets at nine centric/non-centric sites. Brain deformation metrics were calculated using the University College Dublin Brain Trauma Model. The results revealed that design characteristics do influence the brain deformation metrics associated with incidence of con-cussion. Further analysis revealed that rotational acceleration was more related to brain deformation metrics than linear acceleration. These results show that when attempting to reduce brain deformation metrics, the development of rotational acceleration diminishing technologies may be beneficial. This research indicates that helmet design may be able to reduce the risk of concussive injury.