I think coaching philosophy is also a factor.
A not insignificant number of last year's injuries happened when players were attempting to get more out of a play than the play actually provided for.
Off the top of my head, I can remember Wilson and Deebo getting hurt by their maniacal determination to run through defenders.That's their game, and Shanahan loves them for it, but it comes at a cost, and sometimes that cost is availability.
The whole YAC philosophy that much of our offense is built on puts players in more situations where they are likely to get hurt.
Kittle got hurt making a catch with an awkward pirouette (so his feet were not directly under him, much like how the Warrior's James Wiseman was lost for the season this year on an awkward one-legged leap at the rim). Nice play, but no more Kittle for quite a few games.
Jimmy got hurt once when he put his head down to go through a defender on the left sideline in a futile (though admirable) attempt to get an important first down. Another time (or maybe twice?), Jimmy got hurt when he tried in vain to escape a sack, leaving his ankle exposed, when a smarter approach might have been to cut his losses on that play, curl into a ball for safety, protect the football, and accept the sack.
My memory's not perfect, but you get the idea, and I know there were other, perhaps better, examples of this, I don't keep lists of them, lol.
It's football, and some of these things are how you win, but at some point you have to find the balance of taking what is there from a particular play and living to fight another day.
I would think that balance and proportionate risk would be skills that could be taught and worked on, so conditioning coach stuff (though maybe non-traditional approaches would be best to teach this), but also the overall coaching philosophy that tries to maximize the YAC or outcome of every play beyond its safe threshold has a great cost.
Watch someone like Russell Wilson. He finds clever and effective ways to escape and/or to run upfield, and rarely gets squared up. Sacked a lot, makes hella plays upfield, but rarely gets hurt. He's not looking for YAC, he's looking to avoid contact, and when it's imminent, he puts his body in a safe position for it (often sliding when upfield), it's something he has mastered.
Frank Gore is another example of a guy who knows how to get a lot out of a play but not in a reckless way, he keeps his feet under control and underneath him, and when the play's over, he takes care of the ball and goes down to safety.
Jerry Rice was another player who sure as hell knew how to get a lot out of a play, combining great balance and control with intelligence that told him, despite his conviction that every time he had the ball he should score, how to reasonably come to terms with how a play was resolving so he could keep playing.
I'm not saying this explains all of our problems, obviously a number of these injuries (such as Bosa's) don't fit this profile, but I think our team, more than most, has a lot of injuries that do. Something to consider.
[ Edited by FiftyNiner on May 6, 2021 at 12:34 AM ]