I've wondered about this. The constant harping on keeping arms in might be something. Maybe guys are just stronger too, if a DE gets around, it could definitely twist some muscles trying to turn after him. The league is very cautious about any hands that even look like they go above shoulder pads. a 15 yard penalty is a nightmare for these guys, so change in technique? Too many bench presses during lifting? It's hard to say, but I've never really heard of so many before. I'm with you Felix, seems odd, then again the game is always changing and guys are faster and stronger so they are more difficult to push back maybe. Turf could also play an issue. If the field is looser or not as sure footed for players, this could cause some pulls. ???
Maybe someone should invent the man bra, a strap not unlike a knee brace that wraps around the pectorals. Not to mention, in today's social climate of whack jobs it'd probably sell a shit ton