Impact testing methods to simulate head impacts due to falls from standing height

Fall is one of the leading causes of traumatic brain injury (TBI), and thus, there is an increasing interest in validated tools and protective devices to prevent fall-related TBI. Developing head protective technologies for fall requires a reliable testing method to realistically mimic kinematics of head impacts due to fall to evaluate the injury attenuation of such protective headgears. The objective of this study is to recommend an appropriate and repeatable testing method for simulating fall-related head impacts due to standing height falls. To that end, several impact testing methods that commonly use to assess the efficacy of protective headgear were evaluated and compared. The four different test methods include: (1) a whole-body anthropomorphic test device (ATD) drop; (2) a drop-tower equipped with a Hybrid III head and neck assembly; (3) ASTM F429/F1446 standard; and (4) a linear impactor equipped with a Hybrid III head and neck assembly. Although the ATD drop system simulates fall-related head impacts realistically by considering the whole-body kinematics during falls from standing height, this method showed low repeatability. Among the three repeatable testing methods, only the drop tower with Hybrid III head and neck assembly showed statistically similar results to the ATD drop system for front and rear head impacts for all parameters examined in this study including peak linear acceleration, Head Injury Criterion, peak angular acceleration and peak angular velocity. The results suggested that drop-tower with Hybrid III head and neck assembly can realistically captured both translational and rotational motions of the head during impact due to standing height falls in a repeatable manner.