没提战场包扎的问题，和士气，仪式，卫生有点关系，中国也许说法不同？
美国有个电影叫jarhead.
Military
The practice of shaving heads has been used in the military. Although sometimes explained as being for hygiene reasons, the image of strict, disciplined conformity may certainly be a factor. During World War II's Allied invasion of Normandy on D-Day, many soldiers chose to have their heads completely shaved, denying the defending Germans something to grab onto when the battle moved to close quarters. For the new recruit, it can be a rite of passage, and variations become a badge of honour.
The militaries of the United States, Russia, and several other countries have welcomed their recruits by giving them haircuts using hair clippers with no guard attached. As of 2011, shaved heads continued to be standard haircuts in the United States Air Force, United States Marine Corps, United States Army, and the United States Coast Guard during basic/recruit training – upon graduation from training, grooming restrictions are relaxed in accordance with each service's regulations. In Greece, this practice was abolished on June 25, 1982, when the military started allowing recruits to have up to 4 cm of hair. Before then, the regulation haircut in the Greek army for recruits was en hro (an archaic phrase for "shaved to the bone").
A shaved head continues to be common place in the United States military. There have been traditions spawned from shaving a service members head. Most notable is the tradition of shaving one's head when a service member enters the Mediterranean Sea by ship for the first time, known as "Med Head"[citation needed].
Prison and punishment
Prisoners commonly have their heads shaven, often ostensibly to prevent the spread of lice, but may also be used as a demeaning measure.
Having the head shaved can be a punishment prescribed in law.[2]
The Nazis punished persons accused of Rassenschande (racial defilement) by parading them through the streets with shaved heads and placards around their necks detailing their crime.[3]
During and after the end of World War II, thousands of French women had their heads shaved in front of cheering crowds as punishment for collaborating with the Nazis during the war.[4][5][6] Also some Finnish women got their heads shaved for allegedly having relationships with Soviet POWs during World War II.[7]
