Defensive Lineman Techniques in a 3-4/50 Front

we start our d-lineman off crowding the line...however, if they are getting too deep with their penetration, we will back them off 12-18 inches...as far as technique..we are in a 4 point sprinters stance, we teach it the same as a sprinter in track....we place our hind foot in the direction that we are going(right foot back if we are slanting right)we take a 45 degree directional step up field...if we get pressure we rip...if there is no pressure,we close off of the down block........