Ice hockey is most popular in Canada, central and eastern Europe and the northern regions of the US. Ice hockey is the official national winter sports of Canada,where the modern version of the sport was created, and enjoys immense popularity; alongside Canada, hockey is the most popular winter sport in Finland the Belarus and Switzerland. Ice hockey is a content team sports played on ice, usually in a rink, in which two teams of skaters use their sticks to shoot a vulcanized rubber puck into their opponent’s nqet to score points. The sport is known to be fast-paced and physical, with teams usually consisting of six players each: one goaltender, and five players who skate up and down the ice trying to take the puck and score a goal against the opposing team. Ice hockey is used in places where hockey more often refers to field hockey such as , Asia, Africa, and some European countries. In Russia and Ukraine, where hockey can also refer to bandy, ice hockey is often called hockey with puck. The two most important codes are those of the llHf and the NHL.Both of the codes, and others, originated from Canadian rules of ice hockey of the early 20th Century. During normal play, there are six players per side on the ice at any time, one of them being the goaltender, each of whom is on ice skates. The objective of the game is to score goals by shooting a hard vulcanized rubber disc, the puck, into the opponent’s goal net, which is placed at the opposite end of the rink. The players use their sticks to pass or shoot the puck. Within certain restrictions, players may redirect the puck with any part of their body. Players may not hold the puck in their hand and are prohibited from using their hands to pass the puck to their teammates, unless they are in the defensive zone. Players are also prohibited from kicking the puck into the opponent’s goal, though intentional redirections off the skate are permitted. Players may not intentionally bat the puck into the net with their hands. Between the six players on the ice, they are typically divided into three forwards, two defencemen, and a goaltender. The term skaters is typically used to describe all players who are not goaltenders. The forward positions consist of a centre and two wingers: a left wing and a right wing. Forwards often play together as units or lines, with the same three forwards always playing together. The defensemen usually stay together as a pair generally divided between left and right. Left and right side wingers or defencemen are generally positioned as such, based on the side on which they carry their stick. A substitution of an entire unit at once is called a line change. Teams typically employ alternate sets of forward lines and defensive pairings when shorthanded or on a power play. The goaltender stands in a, usually blue, semi-circle called the crease in the defensive zone keeping pucks from going in. Substitutions are permitted at any time during the game, although during a stoppage of play the home team is permitted the final change. When players are substituted during play, it is called changing on the fly. A new NHL rule added in the 2005 06 season prevents a team from changing their line after they ice the puck. ice hockey, infractions of the rules lead to play stoppages whereby the play is restarted at a face off. Some infractions result in the imposition of a penalty to a player or team. In the simplest case, the offending player is sent to the penalty box and their team has to play with one less player on the ice for a designated amount of time. Minor penalties last for two minutes, major penalties last for five minutes, and a double minor penalty is two consecutive penalties of two minutes duration. A single minor penalty may be extended by a further two minutes for causing visible injury to the victimized player. This is usually when blood is drawn during high sticking. Players may be also assessed personal extended penalties or game expulsions for misconduct in addition to the penalty or penalties their team must serve. The team that has been given a penalty is said to be playing short-handed while the opposing team is on a power play. In In the case of a goal scored during the first two minutes of a double-minor, the penalty clock is set down to two minutes upon a score, effectively expiring the first minor penalty. Five-minute major penalties are called for especially violent instances of most minor infractions that result in intentional injury to an opponent, or when a “minor” penalty results in visible injury , as well as for fighting. Major penalties are always served in full; they do not terminate on a goal scored by the other team. Major penalties assessed for fighting are typically offsetting, meaning neither team is short-handed and the players exit the penalty box upon a stoppage of play following the expiration of their respective penalties. The foul of “boarding” is penalized either by a minor or major penalty at the discretion of the referee, based on the violent state of the hit. A minor or major penalty for boarding is often assessed when a player checks an opponent from behind and into the boards. Even a shallow cut to the head results in a loss of a large amount of blood. Not only are lacerations common, “it is estimated that direct trauma accounts for 80% of all [hockey] injuries. Most of these injuries are caused by player contact, falls and contact with a puck, high stick and occasionally, a skate blade.One of the causes of head injury is checking from behind. Due to the danger of delivering a check from behind, many leagues, including the NHL have made this a major and game misconduct penalty. Another type of check that accounts for many of the player-to-player contact concussions is a check to the head resulting in a misconduct penalty. A check to the head can be defined as delivering a hit while the receiving player’s head is down and their waist is bent and the aggressor is targeting the opponent player’s head. The most dangerous result of a head injury in hockey can be classified as a concussion. Most concussions occur during player-to-player contact rather than when a player is checked into the boards.