BELLEVILLE - Former Giants offensive lineman David Diehl spoke to students about sports-related head injuries during an assembly Wednesday.

Students at Belleville High School received a lesson from the NFL star on the dangers student athletes face.

Diehl spoke to them about the signs and symptoms of concussions and the importance of getting tested before returning to the sports field.

"Having a concussion is basically your brain bouncing off your skull," Diehl says. "That's something we can't see, but doctors can see.  Playing sports, you can play through an ankle or knee.  But this is different."

Diehl is affiliated with St. Barnabas Hospital, which offers baseline screenings for student athletes. They can be used to determine when a student's brain has healed and is ready to return to the playing field.