Not from youth league all the way up to the NFL. The majority of concussions are from practice. And the accumulated effect of full speed tackling in practice adds to the potential for long term brain damage.

So you run maybe 1-2 drills per week max with full-speed/take-to-the ground tackling. Then you run full speed tackling drills without taking to the ground, 3/4 speed, and slow-motion form tackling the rest of the time.