Head Injury Mechanisms And Injury Criteria

Sections Head Injury Types and Locations Head Injury Mechanisms Head Injury Criteria Head Injury Tolerance Levels

Figure 9

Definition And Anatomy

The head is the entire body part located on and attached to the rest of the body by the neck.  In terms of injuries it has been divided into two zones:

• The skull or cranium, which forms a spherical complex of plate type bone, which contains and protects the brain and forms the attachment to the neck on its base

• The face, which contains the eyes, nose and mouth and is made up of a complex agglomeration of bones, attached to and forms part of the skull, covered in muscles and skin

The brain is obliviously one of the few vital life supporting organs of the body controlling all the voluntary and involuntary motions of the body plus the centre of consciousness.  Brain injuries can be fatal and have long and short-term disabilities.

The face contains the sensory sight (eyes), smell (nose) and taste (mouth) organs as well as the orifices for respiration and intake of food.  Severe injuries to the face can be life threatening if it impairs the ability to breath but also can cause immediate problems in being able to see for egress from the rail vehicle, as well as long-term disability and disfigurement.

The head is a particularly vulnerable body part both due to its exposed position on the flexible neck and the sensitivity of the face and brain to impact injuries.  Direct impact forces and accelerations cause the majority of head injuries.  In the rail environment brain injuries are usually caused be direct impact with rigid objects and surface such as grab handles, seat backs, table and the floor.