The rising awareness of concussions is changing the way children play sports in Massachusetts. From high-tech football helmets to changes in practice drills, coaches are rethinking approaches in order to reduce head injuries among young athletes. Meanwhile, under a recent state law, middle and high schools are stepping up efforts to educate everyone on spotting concussions early and ensuring students do not return to play too soon. As fall seasons begin, here’s a glimpse at what’s next in concussion prevention.