Influence of Impact Direction on the Human Head in Prediction of Subdural Hematoma

Abstract

The objective of the present study was to analyze the effect of different loading directions following impact, and to evaluate existing global head injury criteria. Detailed and parameterized models of the adult human head were created by using the Finite Element Method (FEM). Loads corresponding to the same impact power were imposed in different directions. Furthermore, the Head Injury Criterion (HIC) and the recently proposed Head Impact Power (HIP) criterion were evaluated with respect to the relative motion between the skull and the brain, as well as the strain in the bridging veins. It was found that the influence of impact direction had a substantial effect on the intracranial response. The largest relative skull-brain motion and strain in the bridging veins occurred with the anterior-posterior (AP) and posterior-anterior (PA) rotational impulses. HIC was unable to predict consequences of a pure rotational impulse while HIP needed individual scaling coefficients for the different terms to account for difference in load direction. When using the proposed scaling procedure, a better prediction of subdural hematoma (SDH) was obtained. It is thus suggested that an evaluation of the synergistic terms is necessary to further improve the injury prediction. These variations should be considered when developing new head injury criteria.

The Influence of Impactor Mass on the Dynamic Response of the Hybrid III Headform and Brain Tissue Deformation

“…This finding was consistent with previous research that shows variation occurs in the head kinematics and brain tissue response by changing the parameters of the impact [11][12][13][14][15]21].…”

“…In order to decrease the incidence and risks of head injuries, it is important to better understand the mechanism of these brain injuries. Impact parameters are described using a number of characteristics including impact site, mass, velocity, angle of impact and compliance of impactor, creating unique dynamic head responses and consequently different head and brain injuries [11][12][13][14][15].…”

Application of Auxetic Foam in Sports Helmets

“…A slip plane between a helmet's shell and deformable layer aims to reduce rotational acceleration and is now included in many cycling and snowsports helmets [24]. Evidence supporting slip plane technology's ability to reduce the likelihood of concussion is based on computational models, which have been criticized for not including physical validation [25][26][27]. A similar concept, increasing rotational deformation by reducing shear modulus, has reduced the severity of oblique impacts [22].…”

The influence of dynamic response and brain deformation metrics on the occurrence of subdural hematoma in different regions of the brain

“…10,12,27 Investigators researching SDH using finite element modeling have found that anterior-posterior motion can cause higher strain on the brain tissues and vasculature than lateral motions; 34 however, the study used a tied interface between the skull and brain and was limited, as SDH is thought to result from relative brain skull motion. 16 In 2003, Kleiven 16 used a finite element modeling approach to investigate the directional sensitivity of SDH. He indicated that the largest skull-brain motion, and therefore greatest strains in the brain tissue and vasculature, was found in the anterior-posterior rotational motions, with near 0 for translational motions.…”

“…These results supported the anterior-posterior theory of directional sensitivity for SDH. While lateral tests were conducted, Kleiven 16 found that the relative brain-skull motion and strains were lower for corresponding rotational impulses and even lower for translational motion. Using a finite element model of the human brain, Zhou et al 34 found that anterior-posterior motions potentially cause higher strains in regions associated with SDH than lateral direction motions.…”