Biomechanics of Head Trauma: Head Protection

Protection from injury caused by a blow to the head has been of interest since the beginning of recorded time. Injuries to the brain and its container, the skull, and to the outer covering of the head, the scalp, can be inflicted through a variety of mechanisms. Injuries include lacerations, abrasions, fractures, and other forms of tissue disruption. These are nearly always caused by excessive movement1 of one part of the head relative to another. A scalp laceration is the result of a mechanical action (cutting or tearing) that separates formerly contiguous pieces of scalp. A skull fracture will occur when the skull bone bends more than it is capable of doing without breaking. A brain contusion, for example, is a collection of blood caused by the rupture of blood vessels that have been stretched too much. Separating, bending, and stretching are merely descriptors of somewhat different kinds of movement. To protect against all these kinds of injuries may require a variety of approaches. Basically, however, it comes down to padding and load distribution.