What is "neutral zone"

Transition zone \Tran*si"tion zone\ (Biogeography) The zone lying between the Boreal and Sonoran zones of North America. It includes an eastern or humid subdivision and a western arid one of corresponding temperature comprising the northern Great Plains and the lower slopes of the mountains of the western United States and Mexico. Called also Neutral zone.

n. 1 (context American football English) zone between the defensive line of scrimmage and the offensive line of scrimmage. 2 (context ice hockey English) zone on the playing surface between the attacking zone and the defending zone as delineated by the two blue lines.

Neutral zone may refer to:

In sports:

• Neutral zone (gridiron football), the region between offensive and defensive sides prior to the snap of the ball on a scrimmage play
• Ice hockey rink#Zones, zone between the blue lines in ice hockey
• Neutral zone (cycling), a non-competitive segment of a few miles at the beginning of a bicycle race

In geography:

• Neutral territory
• Neutral zone (territorial entity)
• Saudi–Iraqi neutral zone
• Saudi–Kuwaiti neutral zone

In dentistry:

• Neutral zone (dentistry), where the forces exerted by the muscles of the lips, cheek and tongue are in balance.

In other fields:

• Neutral zone (control theory), concept in control theory
• A Overhead line#Neutral section (phase break) on which electric trains operate but which lacks the overhead lines that power them. Residual momentum is required for such trains to cross a neutral zone.

In Star Trek:

• Star Trek: The Next Generation (pinball), target in the Star Trek: The Next Generation pinball game
• List of Star Trek regions of space#Neutral Zone, "buffer zone" between the territories of two different powers in the fictional Star Trek universe
• The Neutral Zone (Star Trek: The Next Generation), the finale of the first season of Star Trek: The Next Generation

In gridiron football, the neutral zone is an area in which no member of either team may be, other than the person holding the ball. The neutral zone only exists in dead ball situations (i.e. when play is not ongoing).

In American football, the neutral zone can be described as the length of the football (11 inches/28 centimeters) from one tip to the other when it is spotted (i.e. placed on a certain spot) on the field prior to the snap of the ball during a scrimmage down. In Canadian football, the neutral zone is a full one yard (3 feet or 36 inches) in front of the tip of the ball during a scrimmage down. The snapper (usually the center) is exempt, as he must place his hand on the ball (thus entering the neutral zone) to execute the snap.

The neutral zone is much longer for kickoffs, safety kicks and fair catch kicks, where ten yards separates the kicking team from the receiving team. The kicker and, if used, a holder are allowed to enter this neutral zone. In addition to not being allowed to enter the neutral zone before the kick, the kicking team may not recover their own kick until the ball has traveled beyond the neutral zone or has been touched by an opposing player.

Knowing whether the ball has passed beyond the neutral zone or remained in or behind the neutral zone is important during forward pass plays and during scrimmage kicks.

• "Behind the neutral zone" refers to the "offensive" side of the neutral zone.
• "In the neutral zone" refers to the actual neutral zone.
• "Beyond the neutral zone" refers to the "defensive" side of the neutral zone.

An additional definition of the neutral zone came into effect after a September 12, 2005, fight between the Philadelphia Eagles' Jeremiah Trotter and the Atlanta Falcons' Kevin Mathis that occurred prior to the opening kickoff. The NFL then instituted a rule that each end of the field from the end zone to the 45-yard line is reserved for one team, and that no player other than a kicker may be between the 45-yard lines prior to the game.

Category:American football terminology

A neutral zone is a delimited zone bordering at least one of the states that has agreed to set up a neutral territory. This has occurred in the past and/or present for:

• Neutral Moresnet, a 19th-century neutral zone between the United Kingdom of the Netherlands (and later Belgium) and Prussia (and later the German Empire).
• in the colonial era, the neutral zone between Thailand and French Indochina, 25 kilometres wide (roughly 15.5 miles) on the east bank of the Mekong, was placed under French control but formally remained under Thai sovereignty
• the Saudi–Iraqi neutral zone
• the Saudi–Kuwaiti neutral zone
• the neutral zones between Morocco and Ceuta and Melilla
• Antarctica
• Mount Vernon historic site, home of George Washington, during the US Civil War
• a strip of land in between Macau's Portas do Cerco and China's Kung-pei (Gongbei).

In many cases, a neutral zone is also a demilitarized zone.

In dentistry (particularly prosthodontics and to a lesser extent orthodontics), the neutral zone refers to that space in the oral cavity where the forces exerted by the musculature of the tongue are equal and balanced with the forces exerted by the buccinator muscle of the cheek laterally and the orbicularis oris muscle anteriorly. The neutral zone generally determines the horizontal location of teeth. Teeth are guided into the neutral zone as they erupt into the mouth during childhood development.

The neutral zone is an important concept in prosthodontics, because prosthetic teeth generally must conform to the horizontal position determined by the neutral zone. Prostheses which set teeth outside this zone risk problems such as discomfort, cheek or tongue biting, and instability of the denture.

The neutral zone is also important in orthodontics. Moving teeth outside of this zone means that the muscular forces on the teeth will be out of balance in one direction, and tend to be more likely to relapse to their original position.