You and I both remember when turf became a thing ... and the sharp increase in knee injuries.
Still, I dunno if that's all of it. The NFL still has a fair number of grass fields ... right? Maybe I'm daft on this.
But we seem to see knee and ankle injuries on such slight provocation. Think of Talib's injury on Coliseum grass. (That was a home game, right?) It seemed that nothing had happened ... and he's out months. Or Bradford's ACL just running out of bounds. (Was that at home on turf?)
I dunno. I just remember those old SOBs taking massive punishment. Of course, maybe a lot of it was just teams playing hurt guys and leaving them with bad knees for life.
Anyway, I am occasionally struck by the level of conversation among fans and pundits about dings that in the old days would be largely ignored. And the protections QBs get. Amazing difference.