Theoretical baseball rule question

[Dudd]

So, while unsuccessfully trying to fall asleep, the following question popped into my head. Say a batter hits a homerun, but injures himself running the bases. Pulls a Jason Kendall rounding first and completely shatters his angle, for example. Does the run still count even though he didn't make it home? I know that there are rules against assisting a baserunner (see: Mark McGwire getting grabbed by his first base coach after missing the base on his 62nd home run, obviously not enforced), and I know that there have been cases of guys hitting a walk off homerun with men on base not making it all the way around the bases and getting credited with a single or double. These are the kinds of things that keep me up at night, so I turn to 2+2 for clarification.

[pryor15]

i would imagine in such a scenario the rule wouldn't be enforced and the HR would count.

[asb165]

I am almost positive this happened last year to Gabe Kapler. You are allowed to insert a pinch runner to run around the bases. Actually, after looking it up, Kapler was on 2nd base, didn't know if it was a home run, and while running, tore his achilles. Same rule applies though:

"Instead of going home, Kapler was loaded onto a cart and taken off the field, leading to a scene so rare that an umpiring crew that included John Hirschbeck, a big-league ump for over 22 years, and Wally Bell (13 years), had never witnessed it. While Graffanino waited at second base -- he would have been out if he had passed the runner -- a pinch runner, Alejandro Machado, entered the game.

That substitution was allowed under the Official Rules of Major League Baseball 5.10 (c), which reads: ''When an accident incapacitates a player or an umpire:

(1) If an accident to a runner is such as to prevent him from proceeding to a base to which he is entitled, as on a home run hit out of the playing field . . . a substitute runner shall be permitted to complete the play."

[RogerZBT]

A pinch runner could be inserted and finish rounding the bases, so the run would definitely count. I'm not sure what the scoring would be. I'd guess credit a HR and any RBI to the batter and the run to the pinch runner.