at this stage (three-four years after his original concussions), the acute effects of a concussion such as headaches, inability to focus, vertigo, etc have stopped. the inflammation in his brain has largely subsided. but now is when he the long term effects of chronic traumatic encephlopathy might be setting in. in many, perhaps most cases of concussions/tbi/cte the true effects arent felt for several years sometimes even decades. at this stage sid, there is scarring in the brain that leads to impairment in visuospatial functioning (a recent paper found that visual working memory in athletes is impaired following tbi), executive functioning (decision-making), mood, personality, and behavior, etc. these effects are very subtle at first but can become more pronounced with time.
this stuff about his soft tissue injury/vertebral fracture injury causing all his symptoms is hogwash. thats was reported by one guy who ran with it, and pens fans have clung to it because it sounds better than sid having a concussion. his symptoms werent even consistent with the reported injury. no one on the previous or present medical staff ever said that and i have spoken to the docs on the previous medical staff and they agreed unequivocally that sid had one maybe two standard concussions.
Just stop.
Crosby led the NHL in points in 2013-14 with 104. No one has surpassed 90 since then. This has nothing to do with injuries or lingering effects of them. This has to do with two things: The NHL, which has stifled scoring and creativity; and Mike Johnston's anemic system.
NHL teams averaged 230 fewer power play opportunities last year than they did in 2005-06. That's a problem.
And while injuries hurt the Penguins at times last year, they were predominantly healthy in February and March (Despres was traded in March and Letang went out in the second to last game of the month) and scored an anemic 2 goals per game.
It's the system. Johnston's system is too regimented and scripted, and it's stifling the creativity. Not one of the Penguins' goals this year, save for maybe Letang's, has come via offensive pressure and creativity. It's all come off of turnovers or the occasional odd-man rush (or Malkin doing it himself).
That is the biggest reason behind the Penguins' drop-off in production, especially Sid's. He's built to create in the offensive zone with sustained pressure. He's built to pick apart penalty kills. When you're held back from doing those two things, your production is going to slip.
And let's keep in mind that if not for the mumps & a nagging bruise or pull here and there, Crosby probably leads the league in points last year, too, instead of finishing 3 behind Benn.