Henderson runs non-stop for most of the match.
This is possibly just as much of a reason as any other.
Michael Johnson, he of 400 metre fame, used to run on tracks (a bit more firm than football pitches) with a very strange gait. Did he complain about stress injuries?
Anyway, if it is his gait causing the problems, it shouldn't become too bad a problem until we don't need him anymore...
Michael Johnson was unusual because he broke convention with regard to how people thought the quickest way to run was.
But yes he suffered stress fractures and plenty of other injuries. And you have to bear in mind he'd never perform anywhere near as regulalry as Henderson.
Are we going to do a run down of everyone who ran funny to see if they were ever injured, so we can disprove the notion that biomechanics are related to injury