In the episode Maud Pie, Maud Pie
manages to smash a giant boulder to pieces with a ratatatat-motion.
This gives me the really weird idea...what if this is an imperfect form of a certain technique? Specifically, Ryouga Hibiki's Breaking Point technique? At one point in the past, Ryouga got so lost he ended up in Equestria, turned into a pony, and mentors Maud Pie. She's got the strength to keep up with him, at least. Probably a friendship/Ryouga teaches Maud martial arts story.
Limestone Pie would be standing off to the side, continuing to be a bitchy tsundere. She'd probably be the first pony Ryouga meets, actually. I have the perfect scene in my head already. He accidentally enters Equestria and after finding himself lost, sits on a giant boulder. Cue Limestone freaking out: "DON'T TOUCH HOULDERS BOULDER!"