| A helmet is a form of protective clothing | | | | other warring nations. |
| worn on the head and usually made of metal or | | | | |
| other hard substance, such as Kevlar, resin | | | | World War I and its increased use of heavy |
| fiber, or plastic typically for protection of | | | | artillery had renewed the need for steel |
| the head in combat, or in civilian life, from | | | | helmets, which were quickly introduced by all |
| sports injuries, falling objects or | | | | the combatant nations for their foot |
| high-speed collisions. | | | | soldiers. In the 20th century, such helmets |
| | | | offered protection for the head from shrapnel |
| Helmets are common in the military, | | | | and spent, or glancing bullets. |
| construction, mining, and some sports, | | | | |
| including american football, baseball, ice | | | | The use of protective helmets by millions of |
| hockey, equestrian sports, motorsports, and | | | | fighting men in the two world wars increased |
| rock climbing. Motorcycle helmets and bicycle | | | | awareness of "hard hat" protection. By the |
| helmets are compulsory headgear in some | | | | 1950s, hundreds of new applications for |
| jurisdictions; in the United Kingdom only | | | | helmets were found. The helmet offered an |
| Sikhs are allowed to ride motorcycles without | | | | unexpected advantage: Symbolism. It can |
| wearing motorcycle helmets. Bicycle helmet | | | | signify that, like a soldier, the wearer is |
| compulsion and even strong promotion has been | | | | someone qualified for or capable of a certain |
| a heated subject of debate amongst cyclists | | | | task or activity, such as construction, |
| and scientists since at least the 1990's, | | | | operation of heavy machinery, or |
| lately focusing on alleged net protective | | | | participation in certain sports. |
| effect at the population level. | | | | |
| | | | Today's militaries often use high-quality |
| Helmets were among the oldest forms of combat | | | | helmets made of ballistic materials such as |
| protection, and are known to have been worn | | | | Kevlar, which have excellent bullet and |
| by ancient Greeks, Romans, throughout the | | | | fragmentation stopping power. Some helmets |
| Middle Ages, and up to the end of the 1600s | | | | also have good non-ballistic protective |
| by many combatants. At that time, they were | | | | qualities, though many do not. Non-ballistic |
| purely military equipment, protecting the | | | | injuries may be caused by many things, |
| head from cutting blows with swords, flying | | | | including (but not limited to) concussive |
| arrows, and low-velocity musketry. They were | | | | shockwaves from explosions, motor vehicle |
| initially constructed from leather, and then | | | | accidents, or falls. |
| bronze and iron during the Bronze and Iron | | | | |
| Ages, but soon came to be made entirely from | | | | Function and structure |
| forged steel in many societies after about | | | | |
| 950A.D. Military use of helmets declined | | | | Despite various designs and requirements, |
| after 1670, and rifled firearms ended their | | | | helmets always protect the user's head |
| use by foot soldiers after 1700. By the 18th | | | | through a mechanical energy-absorption |
| century, cavalry units often wore steel body | | | | process. Therefore, their structure and |
| cuirasses, and frequently metal skull | | | | protective capacity are altered in |
| protectors under their hats, called | | | | high-energy impacts. Beside their |
| "secrets". The often-ridiculed Prussian | | | | energy-absorption capability, their volume |
| spiked helmet, or Pickelhaube, saved many | | | | and weight are also important issues, since |
| soldiers by diverting sideways otherwise | | | | higher volume and weight increase the injury |
| mortal sabre blows to the head. Its | | | | risk for the user's head and neck. |
| usefulness was ended by the increased use of | | | | |
| heavy artillery during World War I, replaced | | | | Classical helmets from the ancient Greeks to |
| by the German steel helmet, or Stahlhelm, and | | | | today treat the head uniformly and are |
| afterwards it was worn merely for tradition. | | | | currently tested on rigid headforms. |
| | | | Anatomical helmets adapted to the inner head |
| The Napoleonic era saw ornate cavalry helmets | | | | structure were invented by neurosurgeons at |
| reintroduced for cuirassiers and dragoons in | | | | the end of the 20th century. Since the |
| some armies; they continued to be used by | | | | materials are disposed according to the |
| French forces during World War I as late as | | | | anatomical structure of the head, they are |
| 1915, when they were replaced by the new | | | | smaller and lighter than the classical |
| French Adrian helmet. It was soon followed by | | | | helmets. |
| the adoption of similar steel helmets by the | | | | |