[JRutledge]

In football it is very common to touch players and in many cases essential as an official. If you have a fumble and you have to dig in a pile to get the ball, you need to touch the players and in some cases tap the players to let them know they need to get up when they do not have the ball. Also there is a lot of padding on the players so it is not like we are touching bear skin or just clothes.

I cannot speak for other sports that it would be common because the only I know of is football.

Peace