Methods for testing helmets are usually based on translatory acceleration vector measurements on a headform-helmet assembly exposed to impact in a special drop test rig. The measured acceleration is assumed to be related to a corresponding degree of brain damage on the helmet wearers head. However, medical research indicates that rotational acceleration above a certain level would have detrimental effects on the brain just as severe as the effects of translatory acceleration. The disregard of rotation in present standards would therefore make helmet testing incomplete and may give users a false impression about helmet protection quality. The question may also be raised if instead of using acceleration it might be better to base helmet testing on impact force, which has possibilities of more complete tests including influence of rotation. Furthermore, force based testing would facilitate production and ensure more reproducible results.