I'm surprised I'm the one posting this.

Toll of Glory

They seem to link all of Campbell's physical ailments with his running style, a position I'd dispute.
If you want to say this his habit of meeting would-be tacklers head-on contributed to concussions, and the after-effects of those concussions have led to his present state, I'd agree with you there.
I do not, however, believe that merely being a physical runner leads to these types of problems. Otherwise, we'd see John David Crowe, Larry Csonka, or Jim Brown with the same issues.

I did find Campbell's complaints about problems getting endorsements saddening. I wonder if he realizes that he isn't a hero to the average college kid who buys a computer, he's a hero to that kid's parents?