DRUMMER CAFE

   I'm not sure what you mean by American vs. German grips, but, with some practice, you can change your grips during playing. Gripping my sticks in a matched position (both sticks are straight out from my hands, with the fingers wrapped one way and the thumbs wrapped the opposite side) is good for driving beats, but I switch to the traditional grip (left hand has the stick at about a 90 degree angle, with the thumb over to control) when I need to be more precise in my sticking.
  This may also help in keeping your hands and wrist more comfortable, as you aren't confined to a single position all the time.