Anterior cruciate ligament (ACL), medial collateral ligament (MCL), and other ligament injuries of the knee can be    devastating for football players and may result in significant loss of playing time and/or require surgical treatment. As player safety and injury prevention continue to be a priority, many players and parents wonder if a knee brace can help prevent major football injuries.
 
Several factors come under consideration when trying to decide whether a player should wear a knee brace: 
Effectiveness in preventing an injury
Play hindrance
Added weight
Unnatural feel
Cost
Practicality of routine use
Possibility of increases in injuries in the hip or ankle
 
Prophylactic knee bracing or using a knee brace to prevent injury in football is controversial, with no clearcut answer from quality studies. Some studies suggest that prophylactic knee bracing helps prevent MCL injuries in “high risk positions” such as offensive and defensive linemen, linebackers, and tight ends and may decrease the severity of injuries when they do occur. However, there is no strong evidence to suggest that the rate of ACL  injuries is decreased by routine use of knee braces. Two published review articles on prophylactic bracing for prevention of knee injuries in football players concluded that data was not clear enough to make a recommendation for or against prophylactic bracing.
 
Widespread, routine use of prophylactic knee braces is not supported by available evidence or professional society recommendations. However, each player must consider individual factors such as position, level of competition,comfort, and cost when deciding if prophylactic bracing is advisable. As always, open dialogue among players, parents, coaches, athletic trainers, and team physicians is encouraged..