Some players go their entire NFL careers without having an injury that causes them to be sideline for a prolonged period. Others seem to have them season after season, and it isn't like it's always a recurring injury. Sean Lee was lost this season because of a turf toe injury, which wasn't related to his broken hand last year (which he played through) or the reason he fell in the NFL Draft, an ACL tear. Bruce Carter is gone after dislocating his left elbow, after also dropping in the draft because of a knee injury. Felix Jones, who had no significant injuries in college, has had injury after injury as a pro: tearing a ligament as a rookie while rehabbing a hamstring injury; missing games for a knee strain the next year; suffering ankle and shoulder injuries last year, and fighting through problems with both knees this year. So what's the correlation? Is it something in their genes where their ligaments/muscles are tighter or their bones aren't as dense? Is it something in their preparation where they are not getting stretched properly or missing something from their routine? Is it something in their play? Do they throw their bodies around recklessly or not know how to fall right or protect their bodies from being hit wrong? Is it a combination of all three or something else? I know Emmitt Smith talked about massages/chiropractic care being the key to his longevity. I know he also played through pain at times, and was good at not getting hit square on. But these injury problems still perplex me, so I'd appreciate whatever insights anyone might have.