Comment by codingdave

I just went down a small rabbit hole, watching some videos of quadrupedal running, and what struck me was how un-balanced the motion looked. Even the guy who is (one of) the world's fastest has this weird twist in his back while he is doing it, to make sure his knees and elbows don't smack together. That may be sustainable when you are young and strong, but I worry this guy, or anyone else who gets into this, is going to be wracked with long-term damage and in a lot of pain when older.