ABSTRACT
Soldiers have worn helmets and armour for protection from enemy weapons from as early as 1015 BC. The protective equipment has made use of a variety of materials including hair-filled hides, quilted cloth, wood and metals. Helmet design continues to develop with the application of advances in ballistic materials and manufacturing technologies and the need to overcome changes in combat threat, such as the increased exposure to improvised explosive devices (IEDs). The main components of the human head include the scalp, skull, blood vessels, meninges, cerebrospinal fluid (CSF) and the brain. The scalp is 5–7 mm thick and consists of, from exterior to interior, the cutaneous, hair-bearing skin, a subcutaneous connective tissue layer and a thin tendinous layer. These three layers are bound together as a single unit beneath which is loose areolar tissue. The US Enhanced Combat Helmet (ECH) has been in development since 2007 for the US Marine Corps and US Army.
