This exhibit shows the mechanism of an infant rotational acceleration brain injury. A sudden force causes the head to quickly hyperextend backward, while the brain shifts forward and strikes the anterior skull (coup injury). The head then recoils forward and stops sharply, causing the brain to shift backward and strike the posterior skull (contrecoup injury). Bridging veins within the subdural space are torn anteriorly and posteriorly, causing the accumulation of subdural hematomas. Diffuse axonal injuries also occur as a result of acceleration forces on the brain. Differing densities between the grey matter (neurons) and white matter (axons) causes them to shift at varying speeds, shearing the axons at the grey-white matter junction.