The American football game is played between two teams with a maximum of 53 players (NFL rules). Both sides send 11 players to the game and can change some or all of the players on the court at any time.
The side that has possession of the ball is the offensive side, and the goal is to push the ball to the opponent's position as much as possible, and strive to cross the scoring line into the opponent's end zone to score. There are two ways to attack, players run forward with the ball (rushing) or throw the ball forward (passing). The goal of the defender is to prevent the opponent from scoring as much as possible and force them to lose possession of the ball. If the offensive team succeeds in scoring or loses possession of the ball, the two teams will switch offense and defense, and the game will continue on offense and defense in turn until the end of the four quarters.
American football is a fiercely confrontational sport. Due to the common violent collisions in the game, players must wear armor-like protective gear. These protective gear mainly include helmets with cage masks, shoulder pads, and upper body armor that are connected to the chest protector. In addition, according to the league level, it will also include teeth, gloves, and cover the elbows, waist, hips, and crotch. , Thigh, knee pads, etc.
According to statistics, the use of protective gear can reduce the probability of various serious injuries by more than half. Nevertheless, the fierce nature of American football still makes injuries inevitable. Among them, concussions caused by the blunt force of a limb impact are particularly common, and tens of thousands of players are injured every year.