When physics meets biology: low and high-velocity penetration, blunt impact, and blast injuries to the brain.

The incidence of traumatic brain injuries (TBI) in the US has reached epidemic proportions with well over 2 million new cases reported each year. TBI can occur in both civilians and warfighters, with head injuries occurring in both combat and non-combat situations from a variety of threats, including ballistic penetration, acceleration, blunt impact, and blast. Most generally, TBI is a condition in which physical loads exceed the capacity of brain tissues to absorb without injury.

Biophysical mechanisms of traumatic brain injuries.

Despite years of effort to prevent traumatic brain injuries (TBIs), the occurrence of TBI in the United States alone has reached epidemic proportions. When an external force is applied to the head, it is converted into stresses that must be absorbed into the brain or redirected by a helmet or other protective equipment. Complex interactions of the head, neck, and jaw kinematics result in strains in the brain.