The biggest difference between rugby and football is that rugby is a game of avoidance and football is a game of collision. In rugby that extra yard gained or lost in a tackle is inconsequential because the clock never stops and the ball is always live and in play, moving from player to player avoiding contact. Much like soccer, rugby tends to have fewer injuries than other team sports like hockey, football and lacrosse.
Because they don’t wear heavy protective equipment, rugby players are more aware of their physical position, particularly their head, neck and shoulders. By playing for possession of the ball, not yardage, and the rule of no blocking, players tend to be less likely to be injured by other players. Rugby however is a full contact sport and there is always a risk of injury. For more on rugby safety, read this short article written by Dr. Lyle J. Mitchell, past president of the American College of Sports Medicine: Is Rugby a Safe Sport for America’s Youth?