Natalie Silva, a high school senior in Massachusetts, wants to play soccer in college, but she is still recovering from a right knee injury during a game over a year ago. Silva remembers colliding with an opposing player. As she fell, she heard her knee “pop” when her cleats got stuck in the turf on a field where her Uxbridge High School team was playing an away game. “I was playing on an indoor field where the turf is on top of concrete. If it was grass, there would’ve been more cushion,”