ZRod
Heisman Trophy Winner
I don't know that they're more susceptible, it's just much older technology that didn't necessarily have concussions prevention at the forefront. As I understand it one of the major advantage of modern helmets is that they are much lighter. Therefore the player will tend to keep his head up and allow his neck to naturally absorb some of the impact and lessen the load on the head. I may be way off but that's how I understood it and it made since with the way we were always coached to tackle with your head up.