The objective of this study was to determine the influence of impact deflection and neck compliance on the Gadd severity index (GSI), peak linear acceleration, and peak angular acceleration during a front impact to a Hybrid III head using a pneumatic linear impactor. Impact deflection was performed by translating the headform laterally and was shown to be effective at reducing the linear and angular accelerations as well as the GSI. Neck compliance was altered using one Hybrid III 50th percentile neck and two modified Hybrid III necks. A less compliant neck increased linear acceleration but decreased angular acceleration and GSI. When compared with estimated injury thresholds, the results demonstrated that an increase in the lateral translation or a decrease in the neck compliance resulted in a significant decrease in the risk of injury as reflected by peak linear and angular accelerations and the GSI.
Keywords: sports; mild traumatic brain injury; biomechanics; linear acceleration; angular acceleration