Unlike American football, in case of Rugby any kind of screening and obstruction to players who do not have the ball is not allowed. This is the main reason why Rugby is much safer than American football. Unlike American football, only lateral passes are legal, and running and kicking can advance the ball.
The dangers of professional football is a hot topic. Studies have found high rates of concussions, traumatic brain injuries, and a serious brain disorder called chronic traumatic encephalopathy (CTE) in former players. These injuries can have terribly debilitating effects.